Advanced Photodetectors CERN, LNF, Photonis, PSI; ER: 2 yrs (contact person: C. Joram, CERN)

Development and application of novel photodetectors.

The development of novel photodetectors like Hybrid Photodetectors (HPD) and Geiger-mode Avalanche Photodiodes (G-APD), pursued during the past years in close collaboration with industry, led to exciting perspectives for applications ranging from particle physics (e.g. calorimetry, particle identification, tracking using scintillating fibres) to astro-particle physics and medical imaging. The ongoing development program covers concept, design, construction and performance evaluation of various photodetectors. Most of the work is done in close collaboration with the industrial partner Photonis.

The project comprises 3 lines of activities:

(1) Integration of an X-HPD in a pressure sphere and measure performance under water.

(2) Design, construction and test of a scintillating fibre tracker module for ATLAS with G-APD readout. Test of a prototype of a highly granular lead-scintillating fibre or tile-wave length shifter calorimeter readout with G-APDs at the Frascati Test Beam facility.

(3) In collaboration with PSI: Test of a positron emission tomography (PET) camera based on long axially oriented crystals with wavelength shifter strip readout with G-APDs.

The ER will be trained on advanced photodetector design, qualification and applications. He/she will spend several months at our industrial partner Photonis and participate in beam (at Frascati) and possibly phantom tests (PET project).

Concept of a spherical Hybrid Photo Detector with central spacial crystal (X-tal) anode

Possible applications: water (ice) based neutrinodetectors (based on Cherenkov effect).

• Radial electric field negligible transit time spread ~100% collection efficiency no magnetic shielding required

• Large viewing angle (dW ~ 3p)

• Possibility of anode segmentationimaging capability (limited!)

• Sensitivity gain through ‘Double-cathode effect’ QEmax ~ 50% observed.

T ~ 0.4 QE

QE

2A. Braem, NIM A 581, (2007), 469-472.Proceedings of VLVNT08 and NDIP 08 conferences, under publication in NIM A.

X-HPD

X-HPD ½ scale prototype (208 mm Ø) with conical LYSO crystal (PC120)

LYSO 12 Ø × 18 mm

3

4

X-HPD (PC120)

4

Full production at CERN,

supported by Photonis

5

m

q

m

OM in water tank

ER Project: Rebuild a new X-HPD, integrate it in a pressure sphere and test it in a water tank with cosmic rays.

can be rotatedwrt. Euler anglesin the water tank.

17” Pressure sphere (from Antares) with special Genova PMT tube.

C-light

Test set-up available at INFN Genova (M. Taiuti)

6

ATLAS ALFA

Scint. fibre tracking detectors

64-ch. MAPMT tube (X 23)

Hamamatsu G-APD(MPPC) S10362-11, connected to an ALFA fibre, exposed to a Sr-90 source.

~ 10 p.e. (single sided readout)

Sr-90 PMT(Trigger)

Fit = P(m) G(mi,si)not perfect! Sr-90 is not mono-energetic.

Alternative readout device: Geiger mode APD = SiPM

• Compact• Higher QE• Nice signal definition

(photon counting)

Conventional PET geometry Axial PET geometry

AX-PET

Readout of long (LYSO) scintillator crystals with G-APDs.

Extraction of the longitudinal coordinateby a set of WLS strips.

Hardware, electronics, DAQ for 2 camera heads developed/procured. Mechanics being assembled.

Simulation and reconstruction software being developed / optimized

Performance tests with sources and phantoms foreseen in Michigan and/or Zurich.

ER Project: In collaboration with PSI: Test of a positron emission tomography (PET) camera based on long axially oriented crystals with wavelength shifter strip readout with G-APDs.

P7 Advanced Photodetectors 1st year months 2nd year monthsWORK TASK DESCRIPTION

      3   6 9 12   15 18   21 24ER 1 X-HPD                                                

1.1 Induction, literature study, lab and project related training                                            

1.2Processing of X-HPD tube                                      

1.3Training at Photonis                                                

1.3Characterisation of tube in lab        

 

                                     

1.3Training at Photonis                                                

1.4Integration and test of tube in optical module                      

 

                       ER 1 Test of a novel PET camera module                                                

2.1 Induction, literature study, lab and project related training                                                

2.2Lab tests with point source and phantom                                  

 

           ER 1 Scint. Fibre Detector with G-APD readout                                                

2.1 Induction, literature study, lab and project related training                                          

2.2Fabriction of fibre tracker prototype                                      

 

       

2.3Characterization in lab and beam facility                                            

3.6 Test beam at collaborating partner                                              

3.7 MC-PAD annual workshops                       AM                     AM

3.8 MC-PAD network training events (NT)               NT                 NT            

3.9 MC-PAD open training events (OT)                       OT                       OT

D = Deliverable 

activities at network partner (INF)   network training units

M = Milestone   activities at industial partner Photonis

• P7-M1

• P7-D1

• P7-D2

• P7-M2

• P7-D3