2009 IEEE Nuclear Science Symposium and Medical Imaging Conference

Abstract Book

ContentsNuclear Science Symposium .......................................................................................................... 5 NP: NSS Plenary .................................................................................................................... 5 N01: Photodetectors and Scintillation Detectors I ................................................................. 5 N02: Semiconductor Detectors I: Silicon Detectors and Applications .................................. 8 N03: Analog and Digital Circuits I ...................................................................................... 10 N04: Nuclear Measurements and Monitoring Techniques .................................................. 12 N05: New Detector Concepts and Instrumentation I ........................................................... 15 N06: Instrumentation for Homeland Security I ................................................................... 17 N07: Data Acquisition and Analysis Systems I ................................................................... 19 N08: Radiation Damage Effects I: Semiconductor Devices ................................................ 22 J01: Instrumentation for Medical and Biological Research I: Radionuclide Imaging......... 24 N09: Computing and Software for Experiments I: Simulation ........................................... 26 N10: Trigger and Front-End Systems I ................................................................................ 29 N11: Gaseous Detectors I: Development of Techniques ..................................................... 31 N12: High Energy Physics Instrumentation I ...................................................................... 33 J02: Instrumentation for Medical and Biological Research II: X-ray Imaging and Radiotherapy Applications .......................................................... 35 N13: Posters I ....................................................................................................................... 38 J03: Joint NSS/MIC 3 ........................................................................................................ 113 N14: Instrumentation for Homeland Security II ................................................................ 115 N15: Nuclear Physics Instrumentation I ............................................................................ 118 N16: Gaseous Detectors II: Varied Applications in Astrophysics and Particle Physics ... 120 N17: Computing and Software for Experiments II: New Computing Technologies......... 122 J04: Joint NSS/MIC 4 ........................................................................................................ 125 N18: Gamma-ray Imaging I: Compton Imaging ............................................................... 127 N19: Analog and Digital Circuits II................................................................................... 129 N20: Neutron Imaging and Detectors for Neutron Imaging .............................................. 131 N21: Trigger and Front-End Systems II ............................................................................ 134 N22: Semiconductor Detectors II: Silicon Devices ........................................................... 136 N23: Computing and Software for Experiments III: High Energy Physics Computing.... 138 N24: New Detector Concepts and Instrumentation II........................................................ 140 J05: NSS/MIC Joint Posters .............................................................................................. 143 N25: Posters II ................................................................................................................... 150 N26: Gamma-Ray Imaging II ............................................................................................ 229 N27: Analog and Digital Circuits III ................................................................................. 231 N28: Photodetectors and Scintillation Detectors II ........................................................... 2332

N29: New Detector Concepts and Instrumentation III ...................................................... 236 N30: Accelerators and Beam Line Instrumentation........................................................... 238 N31: Semiconductor Detectors III: CZT Detectors ........................................................... 240 N32: Radiation Damage Effects II: Scintillators ............................................................... 243 N33: Computing and Software for Experiments IV: Software for Experimental Applications .................................................................. 244 N34: High Energy Physics Instrumentation II ................................................................... 247 N35: Astrophysics and Space Instrumentation I: Component development ..................... 249 N36: Nuclear Physics Instrumentation II ........................................................................... 251 N37: Astrophysics and Space Instrumentation II: Instruments ......................................... 253 N38: Synchrotron Radiation Instrumentation .................................................................... 255 N39: Computing and Software for Experiments V: Bio-medical Software ...................... 257 N40: Photodetectors and Scintillation Detectors III .......................................................... 259 N41: Semiconductor Detectors IV: CdTe and other Wide Band Gap Materials ............... 261 N42: Data Acquisition and Analysis Systems II................................................................ 263 N43: High Energy Physics Instrumentation III ................................................................. 266 N44: Gaseous Detectors III: GEM Applications in Particle Physics ................................. 268 N45: High Energy Physics Instrumentation IV ................................................................. 270 Medical Imaging Conference ...................................................................................................... 272 J01: Instrumentation for Medical and Biological Research I: Radionuclide Imaging ............................................................................................... 272 J02: Instrumentation for Medical and Biological Research II: X-ray Imaging and Radiotherapy Applications ........................................................ 272 J03: Joint NSS/MIC 3 ........................................................................................................ 272 J04: Joint NSS/MIC 4 ........................................................................................................ 272 M01: Plenary 1 ................................................................................................................... 272 J05: NSS/MIC Joint Posters .............................................................................................. 273 M02: Image Processing and Evaluation ............................................................................ 273 M03: Image Reconstruction 1 ............................................................................................ 275 M04: Quantitative Imaging Techniques ............................................................................ 277 M05: MIC Posters 1 ........................................................................................................... 280 M06: PET/SPECT instrumentation 1................................................................................. 327 M07: Image Reconstruction 2 ............................................................................................ 329 M08: X-ray imaging 1 ....................................................................................................... 332 M09: MIC Posters 2 ........................................................................................................... 335 M10: PET/SPECT instrumentation 2................................................................................. 383 M11: Plenary 2 / Multimodality Instrumentation and Techniques .................................... 385 M12: X-ray imaging 2 ....................................................................................................... 3873

M13: MIC Posters 3 ........................................................................................................... 389 M14: Simulation and Modelling of Medical Imaging Systems ......................................... 436 M15: Animal Imaging Instrumentation and Techniques ................................................... 438 Special Focus Workshops ........................................................................................................... 442 High Performance Medical Imaging (HPMI) 2009 ................................................................ 442 HP1 Platforms and Architectures....................................................................................... 442 HP2 APIs and Applications ............................................................................................... 443 HP3 Physics and Algorithms ............................................................................................. 444 HPP Poster Session ............................................................................................................ 446 Nuclear Techniques Applied to Cultural Heritage ................................................................. 450 CH1 Nuclear Techniques Applied to Cultural Heritage I .................................................. 450 CH2 Nuclear Techniques Applied to Cultural Heritage II ................................................ 452 Contrast in Neutron Imaging .................................................................................................. 453 CN1 Contrast in Neutron Imaging 1 .................................................................................. 453 CN2 Contrast in Neutron Imaging 2 .................................................................................. 455 Author Index ............................................................................................................................... 457 Contributions from Collaborations ......................................................................................... 457 Contributions from Individuals ............................................................................................... 459

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Nuclear Science SymposiumNP: NSS Plenary Monday, Oct. 26 NP-1: 08:30-12:00 International Ballroom Center

The U.S. Nuclear Renaissance and the Challenges It Presents

W. E. Burchill President, American Nuclear Society, La Grange Park, IL, USA Dr. Burchill will discuss the factors that are producing the renaissance of nuclear power in the United States, the current status of that renaissance, and the challenges that it presents. These challenges include re-establishing the United States nuclear infrastructure, addressing political issues, building public confidence, licensing the Yucca Mountain High Level Waste Repository, and closing the nuclear fuel cycle.NP-2:

The Intelligence Advanced Research Projects Activity (IARPA) -- What It Is and Why You Should Care

L. J. Porter Office of the Director of National Intelligence, College Park, MD, USA Dr. Porter will give an overview of the newly created Intelligence Advanced Research Project Activity (IARPA). She will describe its mission, why it was established, what hard problems it is focused on solving, and how researchers can engage with IARPA to help solve those problems.N01: Photodetectors and Scintillation Detectors I Monday, Oct. 26 N01-1: 13:30-15:30 International Ballroom North

A. Burger1, P. Battacharya1, M. Groza1, N. Cherepy2, S. Payne2, B. Sturm2, O. Drury2, E. van Loef3, R. Howrami3, W. Higgins3, K. Shah3, J. Ramey4, L. Boatner4 1 Fisk University, Nashville, TN 37208, USA 2 Lawrence Livermore National Laboratory, Livermore, CA 94550, USA 3 Radiation Monitoring Devices, Watertown, MA 02472, USA 4 Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA This presentation will review recent developments in the emerging strontium iodide scintillator technology. The topics covered will include the handling of precursors, crystal growth and crystal characterization. Results related to purification, synthesis and doping, crystal uniformity and dopant distribution as well as the crystal performance for gamma spectroscopy will be presented and discussed. SrI2(Eu) yields >100,000 photons/MeV in the Eu2+ luminescence band (435 nm central wavelength), with a decay time of ~1.2 microsec, and exhibits excellent light yield proportionality (and hence intrinsic energy resolution) that is superior to that of Cedoped lanthanum bromide [1-5]. We have demonstrated energy resolution of 2.6% at 662 keV, and we observe evidence that a significant component of the resolution broadening derives from material inhomogeneity. For this reason, we are working on improving materials purification, handling and crystal growth methods. In addition, we are developing prototype SrI2(Eu)-based gamma ray spectrometers with optimized optics and pulse processing with the goal of realizing the intrinsic energy resolution limit of SrI2(Eu) for gamma ray spectroscopy, estimated at ~2% at 662 keV. References 1. N.J. Cherepy, G. Hull, A. Drobshoff, S.A. Payne, E. van Loef, C. Wilson, K. Shah, U.N. Roy, A. Burger, L.A. Boatner, W-S Choong, W.W. Moses Strontium and Barium Iodide High Light Yield Scintillators, Appl. Phys. Lett. vol. 92, p. 083508, (2008). 2. R. Hawrami, M. Groza, Y.Cui, A. Burger, M.D Aggarwal, N. Cherepy and S.A. Payne, SrI2, a Novel Scintillator Crystal for Nuclear Isotope Identifiers, Proc. SPIE, Vol. 7079, 70790 (2008).Acknowledgements This work was supported by the Domestic Nuclear Detection Office in the Department of Homeland Security (A. Janos), and performed under the auspices of the U.S. DOE by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Oak Ridge National Laboratory is managed for the U.S. DOE by UT-Battelle under contract DE-AC05-00OR22725.

Recent Developments in Strontium Iodide Detectors

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N01-2:

Luminescence Centers in Ca Co-Doped LSO:Ce Single Crystals

K. Yang, C. L. Melcher Scintillation Materials Research Center, University of Tennessee, Knoxville, TN, USA Recent reports show Ca co-doping significantly reduces the charged trap populations in cerium doped lutetium oxyorthosilicate (Lu2SiO5:Ce, LSO:Ce). Thus afterglow is suppressed and scintillation decay is accelerated. In the present study, we investigate the effect of Ca co-doping on the luminescence centers in LSO:Ce by analyses of photoluminescence decay time, excitation and emission spectra at low temperature as a function of Ca concentrations. It is well-known that Ce doped LSO has two types of Ce luminescence (Ce1 and Ce2) with two distinct sets of excitation and emission spectra and decay constants. In our investigations, emission and excitation spectra of both Ce1 and Ce2 are well resolved at low temperature. These spectra indicate Ca co-doping does not alter the energy level structure of either Ce1 or Ce2 luminescence centers in LSO but changes the relative emission intensities. Photoluminescence decay studies show Ca co-doping has minimal effect on the decay of Ce1 but decreases the decay time measured at Ce2 emission wavelength. Experimental data suggest Ca co-doping reduces the relative population of Ce2 to Ce1. Thus, the luminescence from Ce2 is suppressed, which contributes to the fast scintillation decay property of Ca co-doped LSO:Ce.N01-3:

K. Roemer1, G. Pausch1, C.-M. Herbach1, Y. Kong1, R. Lentering1, C. Plettner1, J. Stein1, M. Moszyski2, L. Swiderski2, T. Szczniak2 1 ICx Technologies GmbH, Solingen, Germany 2 Soltan Institute for Nuclear Studies, wierk-Otwock, Poland Scintillator-based Compton cameras for remote localization and identification of radio nuclides require scatter detectors made of low-Z materials. The energy resolution of such detectors in a range dominated by Compton scattering is a crucial parameter. It has to be known for performance estimates, and it must be quantified and optimized for detector designs to be used in real systems, but it is hard to measure. The Compton Coincidence Technique (CCT) appears as the best method for reliable and direct measurements, but appropriate facilities are expensive. This paper suggests and investigates a modified CCT which provides less expensive means for qualifying of scatter detectors in a reasonable time frame. The assembly consists of a single HPGe detector, the scatter detector to be investigated, and one or more common gamma sources in close geometry. Pulse height and timing information from both detectors is gathered by multi-parameter data acquisition. Coincidences of both detectors are due to a plurality of Compton scattering angles and corresponding energy transfers. A thorough data analysis then allows extracting the detector resolution for multiple energies from data sets measured within hours. Results obtained for NaI, plastic, and CaF2 scatter detectors will be presented and discussed.N01-4: Concentration Dependence of Nonproportionality of LaBr3(Ce), SrI2(Eu), and Other Scintillator Crystals

A Technique for Measuring the Energy Resolution of Low-Z Scintillators

S. Payne1, L. Ahle1, S. Sheets1, N. Cherepy1, W. Moses2, G. Bizarri2, W.-S. Choong2 1 LLNL, Livermore, CA, USA 2 LBNL, Berkeley, CA, USA

We have explored the nonproportionality of numerous crystals including: alkali halides [NaI(Tl), CsI doped with Tl and Na]; LaBr3(Ce) as a function of Ce-doping from 0.5 30%, and other crystals such SrI2(Eu), YAG(Ce), YAP(Ce), and LaCl3(Ce). We have found that we able to model the nonproportionality curves on the basis of three parameters: (dE/dx)ONS which accounts for the attraction between electrons and holes; EXC which is the maximal fraction of excitons that are created following the cascade; and (dE/dx)BIRKS which allows for exciton-exciton annihilation (and the concomitant fall in light yield at low electron energy). During the talk we will develop our model of nonproportionality to explain the electron light yield curves, and also show how Landau fluctuations can be interpreted to explain how the intrinsic resolution can be deduced. Interestingly, there is a small but reproducible change in the LaBr3(Ce) nonproportionality for different concentrations leading a prediction of slightly improved resolution at higher doping - due to diminished exciton creation and annihilation processes.This work is supported by the National Nuclear Security Administration, Office of Defense Nuclear Nonproliferation, Office of Nonproliferation Research and Development (NA-22) of the U.S. Department of Energy and the Domestic Nuclear Detection Office of the Department of Homeland Security. Thanks to Eric Mattmann and Bruno Aleonard from St. Gobain for the loan of the LaBr3(Ce), BrilLanCe 380 crystals. We wish to thank Lynn Boatner (Oak Ridge National Lab), Arnold Burger (Fisk University) and Kanai Shah (RMD, Inc.) for providing crystals. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC5207NA27344 and by Lawrence Berkeley National Laboratory under Contract No. DE-AC02-05CH11231.

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N01-5:

Scintillation Properties of Cs2LiLaCl6

J. Glodo, E. V. D. van Loef, A. Churilov, W. M. Higgins, R. Hawrami, K. S. Shah Radiation Monitoring Devices, Inc., Watertown, MA, USA The elpasolite family is rich in compositions that are very promising for radiation detection. Some of these compositions contain Li ions. Since Li atoms capture neutrons, releasing at the same time charge particles as a byproduct of this process, Li based compositions may be used for thermal neutron detection. The first of the elpasolite crystals proposed for neutron detection was Cs2LiYCl6:Ce (CLYC). Recently, we have been investigating a similar composition: Ce doped Cs2LiLaCl6 (CLLC) for neutron and gamma detection systems. This material shows significantly higher light output than CLYC. While, typically CLYC provides about 20,000 photons/MeV, the light output of CLLC can reach 40,000 photons/MeV. High light output and good linearity allow CLLC to achieve excellent energy resolution of 3.4% FWHM at 662 keV. The thermal neutron detection is readily achieved with CLLC. The gamma equivalent energy for thermal neutron full energy peak is about 3 MeV, thus the light output per neutron can be as high as 120,000 photons. Similar to CLYC, CLLC also exhibits Core-to-Valence Luminescence that is only observed under gamma excitation. This allows pulse shape discrimination to be effectively implemented for this material in order to distinguish between gamma and neutron radiation. In this communication we report our recent results on this material, including its properties versus Ce concentration.N01-6:

N. Cherepy1, J. Kuntz1, J. Roberts1, T. Tillotson1, S. Fisher1, R. Sanner1, W. Ralph1, R. Gaume2, O. Drury1, S. Payne1 1 Lawrence Livermore National Laboratory, Livermore, CA, USA 2 Stanford University, Stanford, CA, USA

Fabrication and Characterization of Transparent Ceramic Garnet Scintillators for Gamma Ray Spectroscopy

Transparent ceramics offer an alternative to single crystal scintillators for gamma ray spectroscopy. We have developed ceramics processing methods involving vacuum sintering and hot pressing for facile fabrication of phase-pure transparent ceramics. Gadolinium-based garnets evidence a large photopeak fraction, however, only a few chemical compositions offer adequate phase stability to be formed as large volume transparent optics. Additionally, materials purity is an important consideration in reducing undesirable afterglow. We have identified several Cerium-doped Gd-based garnet compositions that yield >40,000 Photons/MeV, acceptable phase purity and optical quality ( SCATT > as the ratio of neutron KERMA to proton KERMA is 10-100 for the particle energies expected. Callibration of the pin diode in Vf mode has been performed at the Harper Hospital fast neutron therapy facility, Detroit, and at the KEK Proton Therapy Facillity, Japan, for neutron and proton absorbed dose respectively. Results obtained at the clinical fast neutron beam, Harper Hospital, experimentally demonstrate the relative insensitivity of the Vf diode to protons in a mixed protonneutron field. Experimental results obtained using the dual detector system at the Francis H. Burr Proton Therapy Center, Massachusetts General Hosptial (MGH) will be presented along with GEANT4 simulation results. This work will contribute to the prediction of second cancers in proton therapy, irrespective of the technique used for beam delivery.

PIN Diodes for Measuring Out-of-Field Neutron Dose in Active Beam Proton Therapy

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N13: Posters I Tuesday, Oct. 27 N13-1: 10:30-12:00 Grand Ballroom 4&5

TMRS MK III Engineering Analysis

K. A. Woloshun, G. G. Walthers-Ellis, R. A. Valicenti, J. A. O'Toole Los Alamos National Laboratory, Los Alamos, NM The Target-Moderator-Reflector System (TMRS) is the neutron source for nuclear physics experiments in the Lujan Neutron Scattering Center user facility. The TMRS is an assembly consisting of tungsten targets plus a network of moderators, reflectors and flight paths that deliver neutrons of specified energies and fluxes to surrounding experiments and detector stations. The second-generation TMRS (MK II), operational for 5 years, is scheduled for replacement in 2010. While most features of MK II will remain unchanged, all components of the new TMRS (MK III) have been analyzed for structural integrity and adequacy of cooling consistent with todays engineering standards. This analysis is presented in this paper, with emphasis on 2 features which deviate from the MK II design: 1) The tungsten components of the targets will be clad in tantalum to minimize erosion and consequent contamination of the water cooling system, and 2) A new H2-beryllium moderator/reflector system operating below 100 K will be incorporated.N13-2:

TMRS MK III Engineering Design

J. A. O'toole, R. A. Valicenti, K. A. Woloshun AOT-MDE, Los Alamos National Laboratory, Los Alamos, NM, USA The Target-Moderator-Reflector System (TMRS) is the neutron source for nuclear physics experiments in the Lujan Neutron Scattering Center user facility. The TMRS is an assembly consisting of tungsten targets plus a network of moderators, reflectors and flight paths that deliver neutrons of specified energies and fluxes to surrounding experiments and detector stations. The second-generation TMRS (MK II), operational for 5 years, is scheduled for replacement in 2010. While many features of MK II will remain unchanged this paper describes the engineering design of important new features: 1) The tungsten components of the targets will be clad in tantalum to minimize erosion and consequent contamination of the water cooling system, and 2) A new liquid hydrogen moderator with a beryllium reflector/filter that doubles the neutron flux.N13-3:

R. A. Valicenti1, T. Diaz2, A. T. Nelson3, J. A. O'toole1, D. F. Pruessmann4, K. A. Woloshun1 1 AOT-MDE, Los Alamos National Laboratory, Los Alamos, NM, USA 2 Diaz & Associates, Indian,Well, CA, USA 3 MST-8, Los Alamos National Laboratory, Los Alamos, NM, USA 4 Coronado Machine inc., Albuquerque, NM, USA The Target-Moderator-Reflector System (TMRS) is the neutron source for nuclear physics experiments in the Lujan Neutron Scattering Center user facility. The TMRS is an assembly consisting of tungsten targets plus a network of moderators, reflectors and flight paths that deliver neutrons of specified energies and fluxes to surrounding experiments and detector stations. The second-generation TMRS (MK II), operational for 5 years, is scheduled for replacement in 2010. While many components of the MK II will remain unchanged this paper describe in detail the fabrication and assembly of some of the more complex components of the MK III: 1) The tungsten components of the targets will be clad in tantalum to minimize erosion and consequent contamination of the water cooling system, and 2) A new liquid hydrogen moderator with a beryllium reflector/filter that doubles the neutron flux will be fabricated.N13-4:

TMRS MK III Fabrication

D. J. Peake1, M. J. Boland1,2, G. S. LeBlanc2, G. J. O'Keefe1,3, R. P. Rassool1 1 School of Physics, The University of Melbourne, Parkville, Victoria, Australia 2 Accelerator Physics Group, The Australian Synchrotron, Clayton, Victoria, Australia 3 Center for PET, The Austin Hospital, Heidelberg, Victoria, Australia

Controlling Coupled-Bunch Instabilities at the Australian Synchrotron

In addressing the demands of advanced experiments on 3rd generation light sources, there is a quest to increase to stored beam current and reduce the overall beam size to enhance brilliance. However, these actions can be self-defeating as they can result in instabilities which may ultimately limit the photon flux available to the experimental users. Several techniques have been investigated at the Australian Synchrotron to passively and actively damp instabilities in the stored beam. During normal operations, our approach has been to use a vertical chromaticity of 11 to passively control coupled-bunch instabilities. More recently, we have completed the commissioning a "Bunch-By-Bunch" active feedback system designed around 38

the commercially available Libera Bunch-by-Bunch with hardware and software customised in-house. With all of the existing low-gap insertion devices fully engaged, it has been possible to maintain 200 mA of stored beam at nearzero vertical chromaticity, previously unachievable. Furthermore, the active feedback system also allows for a variety of beam diagnostic measurements to be taken including measuring instability growth rates and calculating beam parameters such as tune and chromaticity. Grow-damp analysis has been used to verify the performance of the system and quantify the potential improvements. This system is now vital for ensuring maximum possible photon flux for the beamline experimentalists.N13-5:

D. J. Peake1, M. J. Boland1,2, G. S. LeBlanc1,2, G. J. O'Keefe1,3, R. P. Rassool1 1 School of Physics, The University of Melbourne, Parkville, Victoria, Australia 2 Accelerator Physics Group, The Australian Synchrotron, Clayton, Victoria, Australia 3 Center for PET, The Austin Hospital, Heidelberg, Victoria, Australia

Design, Construction and Diagnostic Methods of a Real-Time Fill Pattern Monitor at the Australian Synchrotron

Modern third generation light sources provide high-brilliance beams for experimental users, but to futher improve beam brilliance there is an increasing need to know about the temporal nature of the electrons. This article describes the design and construction of a device which allows real-time measurement of the electron density distribution within the storage ring at the Australian Synchrotron. Under the influence of the 500 MHz radiofrequency cavities, the bunch structure in the storage ring is 30-50ps wide gaussians seperated by 2 ns. Utilising the visible light portion of the synchrotron radiation spectrum, the system uses a 30GHz bandwidth MSM photodiode to measure the light emitted from the stored electrons. The signal is then amplified before being digitised by an 8GS/s Acqiris ADC CompactPCI card. An EPICS interface provides the processed signal to the control room which allows remote control of the parameters used to acquire the data. The real-time nature of the system linked with advanced control over the storage ring injection chain has led to the development of methods which enable repeated targeted injections, thereby maintaining an arbitrary fill pattern. This has been exploited in recent instability growth measurements to provide a known flat fill which eases theoretical calculations and allows for multiple measurements to be easily compared. In the future top-up mode user runs can be implemented using this technology. Fill pattern measurements are now being used as an essential tool in the control room for day-to-day operations and diagnostic methods.N13-6:

Design and Development of Laser-RF Synchronization System for Thomson-Scattering X-ray Source at Tsinghua University

Q. Du, J. Li, C. Tang, W. Huang, Y. Du, L. Yan Dept. Engineering Physics, Tsinghua University, Beijing, China Femtosecond X-ray pulses could be generated by Thomson scattering between subpicosecond relativistic electron bunches and ultrashort infrared terra watt laser pulses. To ensure the stability and quality of the X-ray pulses, laser pulse must be synchronized to electron bunch generated by the photocathode RF gun. Here we demonstrate the design and implementation of the Laser-RF Synchronization system in Tsinghua University Thomson Scatter X-ray Source.This work supported by National Natural Science Foundation of China under Grant No. 10735050 N13-7:

F. Garcia1, M. Kalliokoski1, E. Tuominen1, R. Rudolf Janik2, M. Pikna2, B. Sitar2, P. Strmen2, I. Szarka2 1 Detector Laboratory, Helsinki Institute of Physics and Department of Physcal Sciences, University of Helsinki, Helsinki, Finland 2 FMFI Bratislava, Comenius University, Bratislava, Slovakia

GEM-TPC Prototype for Beam Diagnostics of Super-FRS in NUSTAR Experiment of FAIR Facility

The FAIR [1] facility is an international accelerator centre for research with ion and antiproton beams. It is being built at Darmstadt, Germany as an extension to the current GSI research institute. One major part of the facility will be the Super-FRS [2] separator. The NUSTAR experiments will benefit from the Super-FRS, which will deliver an unprecedented range of radioactive ion beams (RIB). These experiments will use beams of different energies and characteristics in three different branches; the high-energy which utilizes the RIB at relativistic energies 300-1500 MeV/u as created in the production process, the low-energy branch aims to use beams in the range of 0-150 MeV/u whereas the ring branch will cool and store beams in the NESR ring. The main tasks for the Super-FRS beam diagnostics chambers will be for the set up and adjustment of the separator as well as to provide tracking and event-by-event particle identification. The Helsinki Institute of Physics and the Comenius University are in a joint R&D phase of a GEM-TPC detector which could satisfy the requirements of such diagnostics chambers in terms of 39

tracking efficiency, space resolution and count rate capability. The current status of the first prototype and simulations results will be shown.N13-8:

C. I. Choi1, B. H. Kang1, Y. K. Kim1, I. W. Choi2, D. K. Ko2, J. M. Lee2, G. D. Kim3 1 Department of nuclear engineering, Hanyang University, Seoul, Korea 2 Center for Femto-Atto Science and Technology, and Advanced Photonics Research Institute, Gwangju Institute of Science Technology, Gwangju, Korea 3 Ion Beam Application Group, Korea Institute of Geoscience and Mineral Resources, Daejeon, Korea An ultraintense pulse-type laser having pulse width of subpicoseconds is one of the most interesting scientific topics and has been studied widely. If the ultraintense laser is focused on targets with intensity over 1018 W/cm2, protons having energies of a few to few tens MeV are generated by laser-plasma interaction called Target Normal Sheath Acceleration (TNSA) [1, 2]. Because the energy spectrum of accelerated protons assumes a shape like figure 1, proton radiography images which are obtained by using the ultraintense laser can show better contrast to thin objects than the mono-energy proton ones. Also, the ultraintense laser doesnt require large facilities and high cost in comparison with conventional accelerators. Because of these advantages, the ultraintense laser is expected to replace the conventional accelerators as energetic ion generation source. The experiments comparing the images of the ultraintense laser of Gwangju Institute of Science Technology (GIST) and those of the Tandem Van de Graaff accelerator of Korea Institute of Geoscience And Mineral resources (KIGAM) were performed. The used phantoms to obtain proton radiographic images were designed by using TRIM code, and then were fabricated with Mylar and polyethylene. The obtained images were evaluated by using factors like a spatial resolution, a contrast, and a Modulation Transfer Function (MTF). The spatial resolutions of images from the ultraintense laser were 9.3, 9.9, 10.9 for each phantom. Experiments using the Tandem accelerator in same condition and comparison of the obtained images will be performed.Acknowledgment : This work was supported by the Ministry of Knowledge and Economy of Korea through the Ultrashort Quantum Beam Facility Program, and also supported by the Basic Atomic Energy Research Institute (BAERI), nuclear R&D program of MEST, Korea. N13-9:

A Study of Proton Radiography Through Comparison Between Ultraintense Laser and Tandem Accelerator

M. Iwasaki1, T. Tauchi2, T. Tsuboyama2 1 University of Tokyo, Bunkyo-ku, Tokyo, Japan 2 KEK, Tsukuba, Ibaraki, Japan

IP Beam Size Measurement During Collisions at Super-KEKB

We report studies of the direct IP beam size measurement during collisions at the future Super-KEKB asymmetric energy e+ecollider experiment by using e+e- pairs. A large number of e+e- pairs are produced during the collisions and deflected in a strong Coulomb potential made by an oncoming beam. Since the potential depends on the vertical and horizontal beam sizes, the deflected pairs are expected to carry the beam size information, especially in their angular distributions. This IP beam size measurement method has been developed for the future e+e- linear collider experiments, where the huge number of e+e- pairs and the strong Coulomb potential are expected because of their high energy beam collisions. We describe the idea of the application to the beam size measurement at Super-KEKB based on its superior high luminosity, and show the first results of the simulation studies.N13-10:

H. Gong1, L. Hou1, M. Zeng1, B. Shao1, Y. Li2, J. Cai3 1 Dept. of Engeering Physics, Tsinghua University, Beijing, Beijing, China 2 National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, China 3 Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, Shanghai, China A Beam Loss Monitoring (BLM) system has been designed for Shanghai Synchrotron Radiation Facility (SSRF). It is helpful to find out the position of vacuum leakage, regulate the machine operation parameters, and study the beam lifetime. The beam loss mechanism is studied in the paper, followed by beam dynamics analysis which gives the location of lost particles along SSRF storage ring. A detailed beam trajectory tracking with the DBA structure of SSRF storage ring under different energy loss ratios also helps to predict the appropriate positions of beam loss monitoring. The beam loss mechanism points out that when particles hit the vacuum chamber wall a shower process occurs. Among this process, shower electrons carry more distinct position information of lost particles than photos and neutrons do. The PIN photodiode BLM detector originally designed at DESY is then employed in this situation for detecting the shower electrons, which is sensitive to shower electrons, but nearly has no response to photos and neutrons. The detectors are installed along the 432 meter ring, most of them are located at the appropriate positions given by calculation and few are mobile to provide more flexibility. A distributed data acquisition system based on embedded system and synchronous Ethernet technology is also designed to collect the signals from all the detectors and transfer to the data 40

Design and Application of Beam Loss Monitoring System for SSRF Storage Ring

storage and analyze workstation. The BLM System described in this paper has been built and contributed to the commissioning of the SSRF storage ring, and been qualified as a sensitive and steady machine diagnostic and radiation protection tool.N13-11:

T. Z. Fullem1, A. M. Kovanen1,2, D. J. Gillich1,2, Y. Danon1 1 Dept. of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY, USA 2 Dept. of Physics, United States Military Academy, West Point, NY, USA

Focused Ion Beam Production Using a Pyroelectric Crystal and a Resistive Glass Tube

We describe the use of a pyroelectric crystal and a resistive glass tube to generate a focused ion beam. A sharp tip was mounted on one surface of the crystal which ionized a low pressure deuterium gas and a resistive glass tube was mounted coaxially with the tip. The resultant ion beam produced an illuminated spot on a ZnS screen. It was found that the spot size increased as the distance between the screen and the end of the resistive glass tube increased.N13-12:

P. S. Yoon1, D. P. Siddons1,2 1 National Synchrotron Light Source-II, Brookhaven National Laboratory, UPTON, NY, USA 2 National Synchrotron Light Source, Brookhaven National Laboratory, UPTON, NY, USA

Development of a Photodiode-Based X-Ray Beam-Position Monitor with High-Spatial Resolution for Use on NSLS-II Beamlines

We have developed a photodiode-based X-ray beam-position monitor with high-spatial resolution for use on the future project beamlines at NSLS-II. A ring array of 32 Si PIN photodiodes were fabricated as a photon sensor, and a low-noise HERMES4 ASIC die was integrated into the data-acquisition system. A series of precision measurements for electrical characterization of the multi-segmented Si-photodiode sensor and the ASIC die demonstrated that the inherent detector noise is sufficiently below tolerance levels. Following up with the efforts of modeling detector performance including geometrical optimization with a Gaussian beam, we built the first-version of prototype detector. As a result of the geometrical optimization via analytical modeling, the next versions of the ring diode are currently under development. To find an X-ray beam centroid using the ring photodiode, we devised a new method of fitting polar coordinates measured from a ring array of 32 segments. In this paper, we present the development of the new front-end monochromatic X-ray BPM and subsequent experimental measurements performed on an existing beamline at NSLS.N13-13:

A. Ratti1, J.-F. Beche1, J. Byrd1, P. Denes1, L. Doolittle1, P. F. Manfredi1, H. Matis1, M. Monroy1, M. Placidi1, T. Stezelberger1, W. Turner1, H. Yaver1, E. Bravin2, A. Dress3, J. Stiller4, K. Chow1 1 Lawrence Berkeley National Laboratory, Berkeley, CA, USA 2 CERN, Geneva, Switzerland 3 Brookhaven National Laboratory, Upton, NY, USA 4 Physikalisches Institut, Ruprecht-Karls-Universitat Heidelberg, Heidelberg, Germany The LHC beam luminosity monitor is a gas ionization chamber that observes showers produced by very forward emitted neutrons at the IPs. The choice of a four quadrant detector could provide information on the beam crossing angle. The system must comply with extremely stringent requirements: resolving the 40 MHz bunch repetition rate of LHC and withstanding extremely high radiation doses (1 GGy/yr). The sensitive volume of the chamber is split into six 1mm gaps to reduce the drift electron clearing time below the 25ns bunch spacing. We chose a mixture of Argon with a few percent (nominally 6%) of Nitrogen. The amplitude of the signal is linearly proportional to the gas pressure and can be chosen up to 10 bar to obtain a desired pulse height. The systems performance was validated with beam in several facilities, such as the ALS, RHIC and the SPS. The 1.5 GeV electron beam from the ALS booster allowed single bunch testing at 1 Hz, with good control of the bunch intensity. In these tests, we were able to characterize the detectors position sensitivity, as well as its response to changes in gas mixture, pressure, or applied bias voltage, validating the models. Testing at an ALS x-ray beamline we could measure the speed of the system using a dedicated 38 MHz bunch pattern. We validated the operation of the device as a luminosity monitor during RHIC run 7. Using the standard RHIC luminosity measurement instrument, the Zero Degree Calorimeter, we placed the detector just between the first and second ZDC modules and found an excellent agreement (better than 99%) when comparing the event rates from the gas ionization chamber and the ZDC during dedicated vernier scans. Finally, the tests at the SPS confirmed the expected signals when measuring the MIPS in showers generated by a 350 GeV proton beam using different absorber thicknesses. This paper describes the final design of the devices as well as the systems modeling and experimental test results.This work was supported by the Director, Office of Science, Office of High Energy Physics, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231

The Luminosity Monitoring System for the Large Hadron Collider (LHC)

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N13-14:

P. Branchini1, A. Aloisio2, S. Loffredo1, V. Izzo1, R. Giordano2 1 INFN, Roma, Italy 2 Universita' Federico II, Napoli, Italy

A High-Precision Time-to-Digital Converter in a FPGA Device

The construction and design process of a highresolution time-interval measuring systems implemented in a SRAM-based FPGA device is discussed in this paper. The TDC use a delay line to interpolate the phase within the system clock cycle. A resolution better than 35 ps has been measured generating time intervals with high precision pulse system whose range spans from tens of ns up to 20 sec and whose resolution is better than 1 ps. The architecture implemented has a very small dead time (less than 2 ns) and it is multi-hit. In this paper we show the main characteristics of the board and the performances achieved in terms of stability, resolution integral and differential non linearity.N13-15:

The GSI Event-Driven TDC with 4 Channels GET4

H. Deppe, H. Flemming Experimte Electronic, GSI Helmholtzzentrum fr Schwerionenforschung GmbH, Darmstadt, Hessen, Germany The GSI Event-driven TDC GET4 is the first prototype of a high resolution low power event driven TDC for the CBM-Time of Flight detector readout. The design specifications according to the CBM-ToF requirements are a very high time resolution of better than 25 ps and a double hit resolution of less than 5 ns. The TDC has to cope with an event rate of up to 50kHz per channel. The time core architecture is based on a Delay Lock Loop followed by a clock driven hit register. For the event handling derandomistion units adapted from FiFo's are implemented and the readout is controlled by a token ring structure. The serialized data transmission could cover different event types like data, error or synchronisation events. The ASIC was submitted in October 2008 and is presently under test at GSI Darmstadt.N13-16:

An FPGA TDC for Time-of-Flight Applications

J. Wu Fermilab, Batavia, IL, USA An 18-channel time-of-flight (TOF) grade time-to-digit converter (TDC) has been implemented in a low cost FPGA device. The TDC has the following unique features. (1) The time recording structures of the TDC is based on the wave union TDC we developed in our previous work. A leading edge of the input hit launches a bit pattern, or wave union into the delay chain-register array structure which yields two usable measurements. The two measurements effectively sub-divide timing bins for each other especially the ultra-wide bins caused by the FPGA logic array block (LAB) structure and improves measurement precision both in terms of maximum bin width and RMS resolution. A coarser measurement on input signal trailing edge is also provided for time-over-threshold (TOT) applications. (2) The TDC supports advanced timing reference distribution schemes that are superior to conventional common start/stop schemes. The TDC has 16 regular measurement channels plus two channels for timing reference. The timing reference is established with multiple measurements rather than single shot common start/stop. An advanced scheme, the mean-timing approach even eliminates needs of high quality timing distribution media. (3) The ASIC-like encapsulation of the FPGA TDC significantly shorten the learning curve for potential users while maintain certain flexibility for various applications. Necessary digital post-processing functions including semi-continuous automatic calibration, data buffer, data link jam prevention logic etc. are integrated into the firmware to provide a turn-key solution for users.N13-17:

WaveDREAM - a DRS4 Based 5 GS/s 12 Bit Digitizer with GBit Ethernet Readout

S. Ritt, R. Dinapoli, U. Hartmann TEM, Paul Scherrer Institute, Villigen, Switzerland A new waveform digitizing board has been designed at PSI, Switzerland. It is based on the patented DRS4 chip, which is capable to digitize eight inputs with 5 GS/s and 12 bits of resolution with only 350 mW of power. The small size of this board (50x100mm2) make it ideally suited to be mounted directly on a detector, while the read out is done through Gigabit Ethernet. A clock distribution system together with the PLL inside the DRS4 chip achieve a system-wide timing precision below 10 ps RMS. Application specific firmware allows to implement TDCs, CFDs, various ADCs and sophisticated triggers in software on this board. The high channel density, precise amplitude and time digitization together with the fast readout speed make this board suitable for a wide range of applications in various particle detectors, including gamma-ray astronomy, TOF systems and PET scanners.

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N13-18:

F. Petulla'1,2, F. de Notaristefani1,2, V. Orsolini Cencelli1,2, E. D'Abramo1,2, A. Fabbri1,2, M. Marinelli3,4, G. Verona Rinati3,4 1 Deparment of Electronic Engineering, University of Rome Roma Tre, Rome, Italy 2 INFN Sez. Roma III, University of Rome Roma Tre, Rome, Italy 3 Deparment of Mechanical Engineering, University of Rome Tor Vergata, Rome, Italy 4 INFN Sez. Roma II, University of Rome Tor Vergata, Rome, Italy Monocrystalline diamond, grown with CVD techniques, is a very good base material for clinical dosimetry sensors. Diamond also shows good physical and electronic properties in term of tissue equivalence and very low dark currents. The sensor current readout is made by electrometers, these are expensive and bulky and, due to the need of shielded cables, can hardly be used for matrix sensor readout. In order to overcome these problems an ASIC, directly bonded to the sensor, could be the most suitable electronic readout. The ASIC shuld be capable of integrating currents smaller than the pA, with a serial intreface to minimize inteconnection cable volume, providing a compact and portable device. This paper describes the main functional ASIC blocks we designed. The ASIC has nine channels that will be able to operate in the clinical dosimetry current range, and one channel dedicated to dark currents integration. We present simulation results for every functional block and the nal chip layout.N13-19:

Interleaved Dual Slope ADC for a Diamond Dosimeter ASIC

A Peak Detect and Hold Circuit Using Ramp Sampling Approach

J. R. Lin, H.-P. Chou Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan The paper presents a peak detect and hold circuit for nuclear radiation pulse amplitude measurement. Two ramps with different slopes are used to sample the input voltage. The two sampled voltage levels are compared to determine whether the waveform is rising or falling and to detect the peak value. The comparator delays and offsets are also cancelled during the comparison. The circuit is designed using 0.18m 1.8V CMOS process. The error of the measured peak value is within 1mV measuring Gaussian pulses with amplitude 1 V and the peaking time from 1 to 12 s.The work is under the auspices of National Science council, Taiwan. N13-20:

A Fast Single Slope ADC with Vernier Delay Line Techniques

W. F. Lin, H. P. Chou Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan The paper presents a high precision fast integrating ADC with 0.18m CMOS technology. The ADC consists of a one-bit flash ADC, an amplitude-to-time converter, and a two-level vernier delay line unit for 8- bit timing measurement. The one-bit flash ADC divides the input range into half and can reduce the nonlinearity of the ramp signal. Three ramp-down generators are used for amplitude to time conversion. Thus, the timing errors associated with comparator delays are cancelled by pairs of timing marks generated at the same voltage level and a precise time interval can be obtained. The two-level vernier delay line unit has 16 delay stages in each level and the time resolution is about 50 ps and the conversion time is less than 0.1 s.The work is under the auspices of National Science council, Taiwan. N13-21:

O. Gevin1, F. Lugiez1, E. Delagnes1, O. Limousin2, A. Meuris2 1 IRFU/SEDI, CEA, Saclay, France 2 IRFU/SAP, CEA, Saclay, France

IDEF-X SX0: a LOW POWER CMOS ASIC for the READOUT of CD(ZN)TE DETECTORS

Since few years, our group is developing a family of ASICs for space applications, named IDeF-X for Imaging Detector Frontend. IDeF-X SX0 is the very last member of the family. It has been designed in the standard AMS CMOS 0.35m process technology. IDeF-X SX0 is a 32 channel analog front-end with self-triggering capability optimized for the readout of 16x16 pixels CdTe or CdZnTe pixellated detectors to build a new low power micro Gamma camera. The architecture of the analog channel includes a Charge Sensitive Amplifier with a continuous reset system, a variable gain stage, a Pole-Zero cancellation stage, a variable shaping time second order low pass filter, a peak detector, and a discriminator. The energy thresholds can be individually settled in each channel thanks to an in channel 6 bit low power DAC. The channel has been optimized to reduce the power consumption which is now 600W per channel; it is five times lower than the power consumption of the previous IDeF-X chip. Moreover, the dynamic range of the ASIC can now be extended to more than 1MeV thanks to the in channel variable gain stage. When no detector is connected to the chip and no leakage current is programmed, the lowest ENC is achieved at a 10.7 s peak time: the noise is 35 electrons rms. In the paper we will detail the performances of the chip including the linearity and the

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dispersion of characteristics between channels. Finally, the circuit will be evaluated by spectroscopy measurements performed with Cd(Zn)Te detectors.N13-22:

A High-Speed 2nV/Hz1/2 16-Channel Current Amplifier IC for PET

J.-P. Rostaing, A. Peizerat, O. Billoint, G. Montemont, O. Monnet DCIS / DTBS, CEA, LETI, MINATEC, Grenoble, France A 16 channel front-end IC dedicated to small animal Positron Emission Tomography has been developed for crossstrip CdTe detectors. Each channel, designed to handle up to 20pF detector capacitance, includes both low voltage (2nV/Hz1/2) and low current (40fA/Hz1/2) noise, high bandwidth (50MHz at 20pF detector capacitance) current amplifier with a gain of 100 for a power consumption of 4.7mW. Both anode and cathode connection to the detector are possible thanks to an external control signal selecting the input common polarity. Input has been designed for maximum peak current of +/-1uA. Additional charge amplifier functionality is available via a single external control pin, extending functionality to X-ray or Gamma-ray detection, fast instrumentation. Circuit size is 2x8 mm2 in 0.35um 3.3V CMOS process. Each channel differential output is buffered by a transconductance amplifier with two balanced differential current outputs compliant with 50 Ohm terminations.This work has been supported by French National Research Agency (ANR) through TecSan program (project Topase-Med n ANR-06-TECS009). The authors would like to thank O. Rossetto et J.P. Richer from LPSC, Grenoble, and all the people who have contributed to the realization of this ASIC. N13-23:

CLOSY: a Very Precise Clock Generation for Timing Measurements and Synchronization of the CBM ToF Wall

K. Koch Experiment Electronics Dept., GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt, Germany In the concept of the CBM-Time of Flight (ToF) detector readout, two phase coupled high-performance frequencies with very low jitter are needed. One is directly used for time measurements with an event driven TDC (GET4 ASIC), the other for synchronous data transportation reasons. Due to that, a new electronics for precise clock generation and distribution has been designed. The main card (CBM-CLOCK-SYTEM) is based on a frequency synthesizer chip to create two phase coupled independent output frequencies with very low jitter ( < 5ps, distributed over a 20 m distance) and an additionally downstream fast CPLD that creates a synchronisation signal, which is needed as a periodically epoch marker for the system.N13-24:

O. Rossetto1, J.-P. Rostaing2, J.-P. Richer1, O. Billoint2, J. Bouvier1, O. Monnet2, A. Peizerat2, G. Montmont2 1 Microelectronic, LPSC CNRS/IN2P3-Grenoble universite, Grenoble, France 2 DTBS, CEA-LETI, Grenoble, France In this paper, we present two circuits designed for pulse readout of a semiconductor PET system: a fast low noise low power front-end preamplifier/shaper, and the processing circuit performing time tagging, energy measurement and digital interfacing with the data acquisition system. Considerations on noise, speed and power consumption are discussed. The system level electronics architecture and its optimization according to the detector architecture is presented. Results of the circuits caracteristics are also presented.N13-25:

INTEGRATED ELECTRONIC for a CdTe BASED PET SYSTEM

A. Abba1, A. Manenti1, A. Suardi1, S. Riboldi2, A. Geraci1 1 Dept. of Electronics, Politecnico di Milano, Milan, Italy 2 Dept. of Physics, Universita' degli Studi di Milano, Milan, Italy

High Performance Analog Front-End for Digital Spectroscopy

In any digital spectroscopy system the signal has to be properly conditioned before sampling by means of analog circuitry. The paper presents an analog fully-differential front-end, with digitally adjustable gain and offset, wide dynamic amplitude of input signals, low noise and linearity error less than 100 ppm. The analog section has been designed bearing in mind also multichannel applications and, consequently, taking into particular account power dissipation, physical size of hosting PCB, and allowing the system to operate in presence of electromagnetic noise, while at the same time minimizing its own radiated emissions.

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N13-26:

M. J. Myjak1, D. Ma2, D. J. Robinson2, G. S. La Rue2, D. R. Hanlen1 1 Pacific Northwest National Laboratory, Richland, WA, USA 2 Washington State University, Pullman, WA, USA

Multi-Channel Data Acquisition System for Nuclear Pulse Processing

We are developing a compact, low-cost electronics platform for acquiring pulse-mode data from multiple radiation detectors. The system can process up to 64 input channels in parallel. We attempted to keep the design as simple as possible, both to reduce power consumption and allow the system to handle a large amount of parallel processing. A front-end ASIC contains a charge integrating amplifier, two comparators, and a switchable current driver for each channel. This circuit implements the first stage of a Wilkinson ADC, in which the integrated charge is converted to a digital pulse whose width is proportional to the charge amplitude. A back-end FPGA digitizes the pulse and controls the switchable current source. The FPGA also implements a novel technique to measure and compensate for leakage current in the sensor head. This paper presents the design of the multi-channel data acquisition system and discusses the performance of the electronics, including the noise, linearity, and count rate throughput.N13-27:

Digital Readout Electronics for Microcalorimeters

H. Tan, J. Collins, W. Hennig, M. Walby, P. Grudberg, W. K. Warburton XIA LLC, Hayward, CA, USA Microcalorimeters are cryogenic radiation detectors that measure the energy of incident photons or particles by the increase of temperature in an absorber. They are capable of achieving ultra-high energy resolution, but only with small active volumes and pulse decay times in the order of milliseconds. Consequently, detection efficiency per detector is low. A practical detector thus requires a large array of microcalorimeters, and either time-domain or frequency domain multiplexing is used to minimize the number of leads exiting the cryostat to room temperature signal processing. Existing readout electronics generally stream the multiplexed data onto a computer hard drive for offline processing. XIA LLC is developing digital microcalorimeter readout electronics that offer real time signal processing. The electronics consist of two major parts: a set of daughter cards and a standardized core processor board. Each daughter card is designed to interface a specific type of microcalorimeter (single outputs, time multiplexed, frequency multiplexed, etc.) to the core processor. The combination of the standardized core plus a set of easily designed and modified daughter cards allows the design to not only meet present detector signal processing requirements but also ensure future expandability to as yet unspecified detector systems. We will first present the general architecture of the daughter cards and the core processor board. Then we will describe the core processor's interleaved multiplexing firmware that is capable of real time digital signal processing for generating either list mode event data or energy histograms. Analysis of a specific daughter card will clarify their design and function. Finally we will discuss the preliminary performance of our digital signal processing algorithms on real microcalorimeter pulses.This research is supported by the U.S. Department of Energy under grant DE-FG02-07ER84760. N13-28:

The Readout Electronics of GEM Detector

Y. Zhao Div.of experimental physics center, Institute of High Energy Physics, Chinese Academy of Sciences, beijing, China The CSNS was under construction sine 2008. One of the spectrometers requires a neutron detector with spatial resolution of better than 0.2 mm in both X and Y directions. In order to meet the neutron detector requirement of CSNS, the GEM, a twodimensional position sensitive detector, was constructed. A prototype of the detector had been constructed at first, using cathode strip readout method to determine the avalanche position. A readout electronics system was also developed. The prototype of readout electronics system has been designed based on VME bus. The system makes up of three parts: Preamplifier Board, Control Logic Generator Board and Data Acquiring and Transferring Board. The Preamplifier Board is designed with charge sensitive amplifier. On the Data Acquiring and Transferring Board, we get the charge value by peak seeking, after AD conversion by the 40Msys 10 bit flash ADC. Both the peak seeking method and the interface with VME bus are achieved by the firmware in one FPGA. The electronics system has 2 work modes: online mode and calibration mode. Under the calibration mode, we got the charge measurement resolution about 0.4 fc. Under the online mode, we got the spatial resolution for the detector about 0.11 mm. The readout electronics system can work normally, and owned a pretty good performance in neutron discriminationN13-29:

Development of a Counting Strip Detector Readout Chip for Precision Compton Polarimetry

M. Karagounis, G. Ahluwalia, M. Gronewald, M. Koch, H. Krueger, N. Wermes Physics Department, University of Bonn, Bonn, Germany A strip detector readout chip used in an individual photon counting detection system for precision Compton polarimetry has been chosen as a platform for the implementation, comparison and the insilicon test of several alternative architectural analog and 45

digital circuit concepts. An analytic result for the noise optimization has been derived based on the EKV model which gives the optimum width of the input transistor of the charge sensitive amplifier as a function of the inversion factor. Apart from the input transistor, the noise contribution from the biasing for a folded and a telescopic preamplifier topology has been also analyzed. The limitations of classic shaping circuits using MOS transistors operating in linear region as feedback elements are emphasized and alternative shaping topologies rest upon linearized transconductance amplifier and MOSFET-C filter are introduced. A potential hazard of synchronous counters reacting on very short clock pulses is described which becomes much less severe when the implementation is changed to asynchronous ripple counters. All digital circuitry has been implemented in Differential Current Logic to reduce crosstalk between the digital and the analog circuitry. The Trade-Offs which are related to the presented architectural options are extracted from measurements and simulations.N13-30:

K. M. C. Koua1, J.-F. Pratte1, A.-A. I. Assane1, N. Viscogliosi1, C. Pepin2, R. Lecomte2, R. Fontaine1 1 Dept. of Electrical and Computer Engineering, Universite de Sherbrooke, Sherbrooke, QC, Canada 2 Dept. of Nuclear Medicine and Radiobiology, Universite de Sherbrooke, Sherbrooke, QC, Canada

Design and Performance of a 0.18-m CMOS Charge Sensitive Preamplifier for the LabPET II, a Novel 64-Channel APD-Based Detector for PET/CT

A novel 64-channel APD-based detector module has been developed for the next generation small animal PET/CT scanners achieving submillimetric spatial resolution. We report on the design and performance of a low-power, low-noise, 0.18-m CMOS Charge Sensitive Preamplifier (CSP) optimised for this new 64-channel APD-based detector. Timing resolution remains one of the most challenging issues with APD-based detectors, even with recent fast scintillators. Hence, fast, low noise performance is required from the CSP to achieve very good timing resolution. The effects of APD gain on Equivalent Noise Charge (ENC) and optimum shaping time was evaluated for a unipolar 3rd order semi-Gaussian filter. For an APD gain of 200 and a shaping time of 30 ns, an ENC of 450 e- rms was calculated using the EKV model, assuming realistic values of the APD capacitance and current noise spectral density. Also, given the high pixel density and large total number of channels, the power budget must be limited to 1 mW per CSP. The CSP consists of a modified telescopic cascode architecture with an NMOS input device. Electronic characterisation of the rise time, linearity, dynamic range, ENC, timing resolution and energy resolution, as well as the effects of APD gain on the performance are reported.N13-31:

Noise Optimization of CMOS CSA in Weak and Moderate Inversion Regions

Y. Li, Z. Deng, Y. Liu Department of Engineering Physics, Tsinghua University, Beijing, China Noise optimization of CSA(charge sensitive amplifier) in scaled CMOS process has been well studied for the input transistor working in strong inversion region. However, it tends to work in weak or moderate inversion region in many applications requiring low power consumption and/or using deep sub-micron processes. 1/f noise coefficient and the gate capacitance are not constant and become more dependent to the bias conditions, which makes noise optimization more complicated. A CSA is designed and tested using 0.35 m CMOS technology. ENC at different bias currents are measured. At moderate inversion region, the maximum current does not yield the minimum ENC. As the bias current increases, the contribution of the series 1/f noise increases and the contribution of the series white noise is non-monotonic. A more accurate noise optimization method for weak and moderate inversion regions will be derivated, considering the bias dependence of the 1/f noise coefficient and gate capacitance.N13-32:

A. Pullia1,2, F. Zocca2 1 Dept. of Physics, University of Milan, Milan, Italy 2 INFN, Milan, Italy

Fast Low-Impedance Output Stage for CMOS Charge Preamplifiers Able to Work at Cryogenic Temperatures

The quality of the output stage is key to the performance of low-noise CMOS preamplifiers of semiconductor detector signals, especially when the preamplifier signal is to be transmitted to a remote receiver. This work deals with the design and optimization of an output-stage circuit architecture particularly suited for low-noise integrated preamplifiers of X and gamma-ray detector signals. The aim of this development is to conjugate a few important features: low output impedance, ability to work at room and cryogenic temperatures, ability to drive a terminated coaxial cable, low power consumption, large voltage swing with a 100 ohm load. In particular we were interested to a large negative voltage swing. The standard solution, i.e. a source-follower stage realized with a p MOSFET, is not adequate because of the so-called body effect, which would severely limit the negative output voltage swing. The proposed circuit structure, inspired by the White follower, builds around a first n-MOSFET configured as source follower, a second n-MOSFET acting as driver for the load current and a negative-feedback loop which stabilizes the working current of the first MOSFET. As a result both a low output impedance and a large negative voltage swing are obtained. We realized the output stage protoype in a 5 V 0.8 m CMOS technology, and obtained a voltage range of -2.5 V with a negative 46

power supply of -3 V and with a 100 ohm load. Using the output stage in a custom JFET-CMOS charge-sensitive preamplifier for germanium detectors we obtained a large negative voltage swing of -2.5 V, a signal rise time of ~13 ns with a resistive load of 100 ohm and a detector capacitance of 16 pF, and a negligible additional noise. The design of a fully symmetric version, able to provide negative as well as positive rail-to-rail signals, will also be discussed.N13-33:

A. Fabbri1,2, V. Orsolini Cencelli1,2, F. de Notaristefani1,2, E. D'Abramo1,2, F. Petulla'1,2, R. Pani3,2, G. Moschini4,2, F. Navarria5,2 1 Departmente of Electronic Engineering,, University of Roma Tre, Roma, Italy 2 INFN - Instituto Nazionale di Fisica Nucleare, Roma, Italy 3 Department of Experimental Medicine and Pathology, University of La Sapienza, Roma, Italy 4 Department of Physics, University of Bologna, Bologna, Italy 5 Department of Physics, Univeristy of Padova, Padova, Italy The gamma cameras built on a LaBr3 crystal and Hamamatsu H8500 that are being developed have a number of channel that can vary from 64 to 256 depending on the number of PSPMTs that are used and, due to the gain differences, channels have to be acquired and corrected individually. In this context, the readout electronics has to be able to acquire and possibly to make computations on a high number of channels at a rate of kiloevents. A possible solution is the use of an FPGA programmed to collect the data and, in parallel, make a preliminary analysis. The high number of pins available on a modern FPGA allows to acquire and to manage all the data coming from the ADCs, driving the control signals and acquiring the data from several device at the same time. The possibility, even on average grade FPGAs, of having clock rate in the 100 MHz range, makes it feasible to make preliminary energy discrimination in order not to overload the communication channel with the control PC that, due to the high number of data, can became the real bottleneck of system.N13-34:

FPGA Based Readout Electronics for Multi Anode PSPMT

C. P. Lambropoulos1, E. G. Zervakis2, A. Nikologiannis2, G. Theodoratos2, D. S. Hatzistratis2 1 Sensors Electronics and Communications Lab and Aircraft Technology Dept., Technological Educational Institute of Chalkida, Psahna-Evia, Greece 2 Sensors Electronics and Communications Lab, Technological Educational Institute of Chalkida, Psahna-Evia, Greece The Photon 4dimensional Digital Information (P4DI) ASIC is a pixel readout integrated circuit to be used in hybrid imagers. It measures the charge induced on the detectors pixel electrodes from the impinging photons irrespective of the dose rate of the radiation field while the time tagging of each photon makes it appropriate for Compton scattering imaging applications. In pixel digitization and storage of the time and amplitude signal are performed. Only pixels with recorded hits are read out. It has been designed in UMC 0.18um CMOS technology and consists of 8x8 pixels matrix and control logic. The chip has been fabricated and bump bonded to a CdZnTe pixel detector. The ASIC architecture and measurement results will be presented.N13-35:

The P4DI ASIC Architecture and Measurement Results

A. Wassatsch1, S. Herrmann2, R. H. Richter1, L. Andricek1 1 Halbleiterlabor, Max-Planck-Institut fr Physik, Munich, Germany 2 Halbleiterlabor, Max-Planck-Institut fr extraterestische Physik, Munich, Germany

A Clustering Engine for Data Rate Reduction in the Belle II Pixel Detector

The DEPFET technology has been chosen as the baseline for the vertex pixel detector of the Belle II experiment at KEK/Japan. This detector consist of 22 modules, each proposed to be equipped with 2x250x1k pixel. With the proposed average readout frequency of 10kHz and 30kHz peak rate a huge data stream of 100Gbit/s will be generated. To reduce this data stream to a more feasible value, we have to take advantage of the low occupancy of approx. 1-2% and the the hit distribution within the pixel array. For this purpose a pipe-lined clustering algorithm was developed, which can handle cluster sizes of 3x3 or 5x5 at full readout speed. These algorithm can handle data from non bricked sensors and also from bricked designs. It is able to reduce the data rate by up to 50%. The collection of the clustered data packages from the row wise parallel pipe-line are controlled by a specially developed output scheduler, which assures together with the corresponding FIFO structures the data-handling capability. To prove the concept and the performance of the algorithms and also to decouple the development of DHP (DataHandling-Processor) unit from the clustering unit, the clustering engine is in the first phase of the project implemented within a separated ASIC. In a second phase both units will be merged into a final data processing unit, which has to fit on the balcony of the thinned DEPFET detector module. In this paper we will present the overall structure of this DCE (DHP Clustering Engine) and also the details of the implemented clustering and output scheduling algorithms. Furthermore the impacts of the constraints on speed, power and area on the developed circuit and the chosen realization given by the experiment environment will be discussed in detail.

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N13-36:

Current Mode Constant Fraction Discriminator for PET Using SiPM(MPPC)

W. Shen, H.-C. Schultz-Coulon Kirchhoff Institute for Physics, University of Heidelberg, Heidelberg, Germany Silicon photomultipliers (SiPMs) are a novel type of solid state photon detector,which have similar internal gain factors as Photomultiplier Tubes (PMT). Due to their low operation bias voltage, magnetic field immunity and small size, this new silicon photon detector can be used in a wide range of applications, such as Positron Emission Tomography (PET). The special features of SiPM such as large pixel number and high gain lead to a large current output in detection of 511keV photon in the PET application. Hence, a novel current-mode monolithic readout scheme can be implemented. As an important time pick-up unit, constant fraction discriminators are generally used in PET for coincidence measurement. Here, we report on a current mode constant fraction discriminator using a current mode non-delay-line method to generate the bipolar shape for the zero-crossing timing. One analog channel using this scheme has been designed and simulated in AMS 0.35m CMOS technology. Both the design and simulation results will be presented.N13-37:

F. Zocca1, A. Pullia1,2, S. Riboldi1,2, C. Cattadori3,4, A. D'Andragora4 1 INFN-Milano, Milano, Italy 2 Dept. of Physics, University of Milano, Milano, Italy 3 INFN-Milano Bicocca, Milano, Italy 4 INFN-LNGS, L'Aquila, Italy

Setup of Cryogenic Front-End Electronic Systems for Germanium Detectors Read-Out

Front-end electronic devices for the read-out of ionizing radiation sensors must operate in many cases at cryogenic temperatures. Sometimes the front-end circuit is divided into a cold part operated at cryogenic temperature and a warm part operated at room temperature outside the cryostat. In other cases this is not possible owing to the physical constraints coming from the experimental setup, the detector system requirements or the apparatus geometry. In this latter cases the front-end circuitry has to operate in its entirety at cryogenic temperature. In this work we focus in particular on front-end read-out systems for High-Purity Germanium (HPGe) detectors, which are usually operated at liquid nitrogen (LN) temperature. We study the strong effects that the changed characteristics of the electronic active and passive devices have on the charge preamplifier design when operated in LN, while taking into account the particularly challenging requirements that the circuit has to meet: radio-purity, physical reliability under thermal cycling, good noise performance (0.1-0.2% resolutions), fast rise time (20 ns) needed for pulse shape analysis applications. The developed circuit consists of an external silicon JFET (Junction Field Effect Transistor), an external feedback network, and an ASIC (Application Specific Integrated Circuit) realized in a 5V 0.8m silicon CMOS technology. We discuss in particular the effects that changes of JFET and MOSFET transconductance have on noise and bandwidth performance of the circuit. We also discuss the effects that a changed performance of passive devices, such as high-value filtering capacitances, may have on the preamplifier response when operated in LN.N13-38:

Low Noise 64-Channel ASIC for Si, GaAs and CdTe Strip Detectors

M. Kachel, P. Grybo, R. Szczygie Department of Measurement and Instrumentation, AGH University of Science and Technology, Cracow, Poland We present a 64-channel low noise ASIC called SXDR64 for low noise digital X-ray imaging systems. The ASIC is aimed to work with DC coupled CdTe and GaAs strip detectors as well as with Si strip detectors. The circuit can operate with input leakage currents in the range from -5 nA up to 10 nA and with the frequency of input pulses up to 1 MHz. The IC control and readout of the data are done via LVDS drivers/receivers, to ensure the possibility of circuit operation in continuous readout mode. Measured gain of the ASIC is 40 V/el and noise is ENC = 133 el. rms, with 1 cm long silicon strip detector with 100 m pitch.N13-39:

W. Dabrowski1, F. Anghinolfi2, N. Dressnandt3, M. Dwuznik1, J. Kaplon2, D. La Marra4, M. Newcomer3, S. Pernecker4, K. Poltorak1, S. G. Sevilla4, K. Swientek1 1 Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krakow, Poland 2 CERN, Geneva, Switzerland 3 Physics Department, University of Pennsylvania, Pennsylvania, USA 4 University of Geneva, Geneva, Switzerland

Design and Performance of the ABCN-25 Readout Chip for the ATLAS Inner Detector Upgrade

A primary challenge of tracking detectors being developed for the SLHC environment is a high occupancy, which affects directly granularity of the detectors and the number of electronic channels, to be about 5- to 10 times higher compared to the present Semiconductor Tracker (SCT) in the Atlas Experiment. As a result, power consumption in the readout chip is one of the most critical issues on top of usual requirements concerning noise and timing parameters, and radiation resistance. These requirements 48

have to be considered taking into account present and expected trends in development of industrial CMOS processes. We present the design and performance of the ABCN-25 readout chip implemented 0.25 m CMOS technology. The front-end design has been optimized for the short, 2.5 cm, silicon strips foreseen in the upgrade of the ATLAS Inner Detector. The core of the readout architecture includes binary front-end, two levels of data buffering, data compression and data serializing circuitry, and is similar to the architecture of the ABCD3T chip used in the present ATLAS SCT detector. In order to ensure required radiation hardness the hardening by layout technique has been used and SEU detection and correction circuitry have been added. The design includes on-chip power management circuitry comprising two types of shunt regulators and a serial regulator. This circuitry makes the ABCN-25 chip compatible with recent developments in the area of power distribution systems for the inner trackers in the S-LHC environment and in particular with serial powering of the detector modules. The chip has been fabricated in 0.25 m CMOS technology and full functionality has been obtained. The design and performance of the analog and digital circuits will be presented and discussed.N13-41:

J. Kaplon1, A. Ceccucci1, P. Jarron1, A. Kluge1, M. Noy1, S. Tiuraniemi1, M. E. Martin Albarran2, F. Marchetto3, G. Mazza3, A. Rivetti3, S. Martoiu3, G. Dellacasa3 1 CERN, Geneva, Switzerland 2 Universit catholique de Louvain, Louvain-la-Neuve, Louvain-la-Neuve, Belgium 3 INFN, Torino, Italy We present the design and test results of a front-end prototype circuit developed in 130 nm CMOS technology for the readout of the Gigatracker pixel detector in NA62 experiment at CERN. The conditions of the experiment set very demanding requirements on the front end electronics in terms of speed, noise and power consumption. The main challenges for the front end amplifier are very high signal hit rate (dead time less than 100 ns, average signal rate 100 kHz) and 100 ps timing resolution combined with the level of affordable power consumption ( 5X from our previous imager and the stand off distance is > 75m. The camera is compact, rugged and has improved background rejection. It can be transported in a 6m long trailer to enable field deployment. We present latest results obtained with the portable neutron scatter camera.N13-237:

S. Mukhopadhyay1, C. J. Stapels1, E. B. Johnson1, E. Chapman1, P. Linsay1, T. Prettyman2, J. F. Christian1 1 Research, Radiation Monitoring Devices, Inc., Watertown, MA, USA 2 Planetary Science Institut, Tucson, AZ, USA Efficient, compact, low-cost radiation detectors, which can be deployed in large numbers, are needed for detecting illegally trafficked nuclear materials. We have designed a neutron detector based on a solid-state optical sensor, a CMOS solid-state photomultiplier (SSPM), which enables the development of compact spectrometers that can efficiently detect neutrons. SSPMbased spectrometers have high sensitivity and high specificity for neutron detection, which provides a robust alternative to the existing 3He detectors. In this work, we characterized the performance of CMOS SSPM for neutron detectors using a Cs2LiLaBr6 (CLLB) scintillator and compared the performance to a helium tube and a PMT-based instrument.N13-238:

Improved Solid-State Neutron Detection Devices

Cryogenic Microcalorimeter Detectors for Ultra-High-Resolution Alpha-Particle Spectrometry

M. K. Bacrania Safeguards Science and Technology, Los Alamos National Laboratory, Los Alamos, NM, USA On behalf of the LANL/NIST/Star Cryoelectronics Microcalorimeter Collaboration Alpha spectrometry is well suited for analyzing low activity samples of radioactive material, such as those encountered in nuclear forensics, environmental sampling, and analytical chemistry. However, typical mixtures of isotopes in such samples exhibit spectra with energy peaks too similar to resolve with conventional silicon detectors. We have demonstrated microcalorimeter detectors with resolution as good as 1.06-keV FWHM for 5.3-MeV alpha particles, approximately a factor of eight better resolution than silicon detectors. With such high resolution, expensive and time-consuming separation of isotopes in a sample may not be required. For example, a microcalorimeter measurement of a mixture of 241-Am and 238-Pu allows for clear separation and identification of energy peaks in the 5-MeV range; such separation is unobtainable with silicon detectors. These microcalorimeter detectors use a superconducting transition-edge sensor, operating at < 100 mK, to measure the temperature change in an absorber from energy deposited by an interacting alpha particle. We have developed a four-detector system that allows for simultaneous measurement of four individual radioactive samples. Signal readout is accomplished by a commercially available superconducting quantum interference device (SQUID) amplifier system. In this talk, we will present an

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overview of and recent measurement results from our microcalorimeter system, and discuss developments in detector pixel design, signal processing, and alpha spectrum analysis.N13-239:

Charged Particle Energy Loss Radiography for Homeland Security Applications

K. N. Borozdin, C. Morris, A. M. Fraser, J. A. Green, F. G. Mariam, L. J. Schultz, L. Cuellar, N. W. Hengartner, A. Saunders, P. L. Walstrom Los Alamos National Laboratory, Los Alamos, NM, U.S.A. We discuss an innovative low-dose approach for detecting shielded SNM based on measuring the energy loss of energetic charged particles penetrating an object. For mono-energetic particles, energy loss depends mainly on the amount of material (or density multiplied by the material thickness) along the tracks, though it is also a function of atomic number Z. The probability density function for energy loss is described by a narrowly peaked Landau-Vavilov distribution, therefore each single particle provides a good measurement of the amount of material it penetrated. A few particles are enough to measure material parameters with high precision, providing for high-quality radiography with extremely low dose. Even a single-projection energy-loss-only radiography would be qualitatively superior to existing technologies based on attenuation of high-energy photons (e.g., X-ray radiography , CAARS). We can however further improve the performance by using multiple beam projections for 3d tomographic imaging and/or by incorporating signals from the multiple Coulomb scattering and nuclear attenuation of the beam. Detection geometry can be modified as required for a particular application. Out method is ideal for moving objects, allowing to scan them at the speed of their natural movement with mobile or stationary system. In future applications, the scanning can be made both at chokepoints or using mobile platforms, such as boats, planes or vehicles.N13-240:

Fast Detection of 3D Planes by a Single Slice Detector Helical CT

W. Bi, Z. Chen, L. Zhang, Y. Xing Department of Engineering Physics, Tsinghua University, Beijing, China In order to accelerate the imaging process and lower the overall system cost, many practical CT systems use single slice detectors and big-pitch helical scanning, especially in the next generation Baggage Scanning systems. Geometry shape detection represents a very important function in these systems. In this paper, we present an online 3D-plane detection solution for these kinds of systems. First, we improve traditional Hough Line detection method and realized the 2.5D Hough Transform to detect the 3D plane. Second, an implementation scheme of the 2.5D Hough Transform and 3D-plane detection using CUDA is presented. We achieve performance 20 times faster than the requirement for practical applications. At Last, we test the method on a series of real baggage scanning results. Our method works effectively in practical applications.N13-241:

M. Petasecca1, M. L. F. Lerch1, C. J. Jackson2, A. F. Gektin3, A. B. Rosenfeld1 1 Centre of Medical Radiation Physics, University of Wollongong, Wollongong, Australia 2 SensL, Cork, Ireland 3 AMCRYS-H, Kharkov, Ukraine

Characterization of an anti-Compton spectrometer based on a CsI(Tl) scintillator and silicon photomultipliers

Since 2001 considerable attention has been directed toward the development of reliable radiation portal monitor (RPM) systems to interdict illicit radioactive material at border control points. In most situations primary screening with RPMs is based simply on the measurement of the radiation count rate. The RPMs do not have the capability to distinguish naturally occurring radioactive material (NORM) or legal shipments of radioactive material, such as medical isotopes, from suspicious nuclear material (SNM). For this reason, following a primary radiation alarm, a secondary screen is required using handheld portable instrumentation with radioisotope identification capabilities to detect the cause of the initial radiation alarm. In this work we suggest an innovative approach and design of the radiation detector module based on the use of two annular CsI(Tl) concentric scintillators coupled to an array 4x4 of 3x3 mm^2 Silicon Photomultipliers (SiPM). This combination allows for the design of very compact and low power detection assemblies.N13-242:

Addressing Different Active Neutron Interrogation Signatures from Fissionable Material

D. L. Chichester, E. H. Seabury Idaho National Laboratory, Idaho Falls, ID, USA In a continuing effort to examine portable methods for implementing active neutron interrogation for detecting shielded fissionable material, simulations and experiments have been conducted to investigate the utility of analyzing multiple timecorrelated signatures. Time correlation here refers to the existence of unique characteristics of the fission interrogation signature related to the start and end of an irradiation as well as characteristics present in between individual pulses of an irradiating source. 110

Traditional measurement approaches in this area have typically worked to detect die-away neutrons after the end of each pulse, neutrons in between pulses related to the decay of neutron emitting fission products, or neutrons or gamma rays related to the decay of neutron emitting fission products after the end of an irradiation exposure. Recognizing that the problem of detection is a problem of low count rates, we have been exploring methods to integrate these signatures with other rarely used signatures to improve detection capabilities for these measurements. In this paper we will discuss these approaches together with observatio