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Nov 30-Dec 5, 2004 Rajendran Raja, RICH2004, Mexico 1
Physics with the MIPP detector and its RICH counter
Rajendran RajaFermilab
• Beam• MIPP experiment
» Physics» Service measurements
• Particle ID• RICH• Results from the Engineering run• Upgrade plans
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MIPP collaboration list
Y. FisyakBrookhaven National Laboratory
R. WinstonEFI, University of Chicago
M.Austin,R.J.PetersonUniversity of Colorado, Boulder,
E.SwallowElmhurst College and EFI
W.Baker,D.Carey,J.Hylen, C.Johnstone,M.Kostin, H.Meyer, N.Mokhov, A.Para, R.Raja,S. StriganovFermi National Accelerator Laboratory
G. Feldman, A.Lebedev, S.SeunHarvard University
P.Hanlet, O.Kamaev,D.Kaplan, H.Rubin,N.SolomeyIllinois Institute of Technology
U.Akgun,G.Aydin,F.Duru,Y.Gunyadin,Y.Onel, A.PenzoUniversity of Iowa
N.Graf, M. Messier,J.PaleyIndiana University
P.D.BarnesJr.,E.Hartouni,M.Heffner,D.Lange,R.Soltz, D.WrightLawrence Livermore Laboratory
H.R.Gustafson,M.Longo, H-K.Park, D.RajaramUniversity of Michigan
A.Bujak, L.Gutay,D.E.MillerPurdue University
T.Bergfeld,A.Godley,S.R.Mishra,C.Rosenfeld,K.WuUniversity of South Carolina
C.Dukes, H.Lane,L.C.Lu,C.Maternick,K.Nelson,A.NormanUniversity of Virginia
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Brief Description of Experiment
• Approved November 2001• Situated in Meson Center 7• Uses 120GeV Main Injector Primary protons to
produce secondary beams of K p from 5 GeV/c to 100 GeV/c to measure particle production cross sections of various nuclei including hydrogen.
• Using a TPC we measure momenta of ~all charged particles produced in the interaction and identify the charged particles in the final state using a combination of dE/dx, ToF, differential Cherenkov and RICH technologies.
• Open Geometry- Lower systematics. TPC gives high statistics. Existing data poor quality.
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Physics Interest• Particle Physics-To acquire unbiased high statistics data with
complete particle id coverage for hadron interactions.» Study non-perturbative QCD hadron dynamics, scaling laws of
particle production» Investigate light meson spectroscopy, pentaquarks?, glueballs
• Nuclear Physics» Investigate strangeness production in nuclei- RHIC connection» Nuclear scaling» Propagation of flavor through nuclei
• Service Measurements» Atmospheric neutrinos – Cross sections of protons and pions on
Nitrogen from 5 GeV- 120 GeV» Improve shower models in MARS, Geant4» Make measurements of production of pions for neutrino
factory/muon collider targets» Proton Radiography– Stockpile Stewardship- National Security» MINOS target measurements – pion production measurements to
control the near/far systematics• HARP at CERN went from 2-15GeV incoming pion and proton beams. MIPP will
go from 5-100 GeV/c for 6 beam species K p -- 420M triggers. 3KHZ TPC.
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MIPP Secondary BeamInstalled in 2003. Delivering slow spill commissioning beam
(40GeV/c positives since February 2004). Finished Engineering run in Aug 2004.
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MIPP Physics Program
MIPP has 4 distinct clientele for its data, which are interconnected. They are
Liquid H2, D2 –non-perturbative QCD p-A, p-rad (aka SURVEY)
NUMI thin and full target measurements
LN2– Atmospheric neutrinos
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Status of MIPP Now-Collision Hall
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TPC
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MIPP-TPC• This Time Projection Chamber, built by the BEVALAC
group at LBL for heavy ion studies currently sits in the E-910 particle production experiment at BNL, that has completed data taking. It took approximately $3million to construct.
• Can handle high multiplicity events. Time to drift across TPC=16 s.
• Electronic equivalent of bubble chamber, high acceptance, with dE/dx capabilities. Dead time 16s. i.e unreacted beam swept out in 8s. Can tolerate 105 particles per second going through it.
• Can handle data taking rate ~60Hz with current electronics. Can increase this to ~1000 Hz with an upgrade.
• TPC dimensions of 96 x 75 x 150 cm.
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MIPP Cherenkov
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•
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Particle Identification• TPC as shown can provide 3separation with dE/ dx up
to 0.7 GeV/c for /K and 1.1 GeV/c for K/p as well as ambiguous additional information in the relativistic rise region.
• In the intermediate region, we use a multi-cell Cerenkov detector. Light is collected by 96 phototubes from reflective mirrors. Filled with C4F10, the Cerenkov thresholds for, K, p are 2.5, 7.5 and 17.5 GeV/c.
• Above 7.5 GeV/c, many particles will go through to the RICH counter and be identified. We use a RICH counter filled with CO2.
• Threshold Ne N2 CO2
•
• K 42 20 17• p 80 38 33
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MIPP Particle ID
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Engineering Run results
• Had RICH fire. Recovered from it 80% of tubes in tact. RICH is now engineered a lot more safely» Flammable tubing on tubes changed» Base soldering corrections redone where needed» HV connections made more robust» VESDA safety trips» HV trips on sparks as well as over-current» Nitrogen purge.
• TPC broke wires– Fixed, Anode HV fixed• PWC5,6 broke wires- Fixed• Drift chambers made functional– re-fused.• BCKOVs auto pressure curves. Worked well• ToF wall worked• Calorimeters worked
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Beam Chamber profiles- BC2
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Preliminary results from Engineering run
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MIPP RICH
• Inherited from SELEX (which ran with Neon at higher momenta)
• MIPP runs with CO2.• It had 89 columns and 32 rows of
phototubes.• Two kind of tubes being used-
» FEU-60 (made in Russia) 70 columns» R-760 Hamamtsu (Japan) 19 columns» Each column has 32 tubes total of 2848 tubes.
• We completely re-designed the front end electronics
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MIPP RICHSelex paper Nucl.Instrum.Meth.A431:53-
69,1999
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MIPP RICH- CO2 characteristicsAverage Refractive index-1.00048Average focal length 991.504cm
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MIPP RICH
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RICH Fire Pictures
• Lost 20% of the phototubes. Redesigned the Safety system
• Vesda, HVTrip circuit, Nitrogen purge
• Flame retardant sleeves
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RICH HV supplies
• Glassman HV systems
• Current trip limits 3x100mA,2x140mA.
• Interlocked with RICH
• Trips upon spark• Put out 900Watts
for ~3000 phototubes
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RICH readout
89 Front-endCards
3 VMEControllers
89 columns of32 PMT's
• Controller sets thresholds, channel masks, and pipeline delays through serial communication line
• Controller receives a trigger gate, transmits it to FEB's and reads out data
• RICH VME controllers are readout by Motorola MVME 2434 PowerPC
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VME Controller
• Contains TI MSP430 micro-controller for slow controls and Altera FPGA clocked at 53 MHz for data readout
• Capable of driving up to 31 daisy-chained front-end cards» Connections require one RJ-11 cable and one
17-pair ribbon cable
• VME communication is A24/D16 format
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Front-end card
• Discrimated signal goes into a 2µs pipeline
• Signals in the pipeline corresponding to trigger gate (strobe) are latched
• Readout signal may come at any time» Boards may be strobed multiple
times thus allowing multi-level trigger
x20
}x32
Pipeline
PMT signal
Latch
To VME controller
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Front-end card
• Micro-controller handles slow controls, Altera FPGA handles readout
• Low power design: <350 mA at 5V per board, cooled convectively
• Discriminator threshold is linear up to 40mV in 0.04mV steps, and non-linear up to 1V» One threshold setting per channel
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RICH rings pattern recognized
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RICH radii for + 40 GeV beam triggers
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Beam Cherenkovs
• Pressure curve Automated- Mini-Daq-APACS 30 minutes per pressure curve.+40GeV/c beam.
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Beam Cherenkovs
• 40 GeV/c negative beam
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Comparing Beam Cherenkov to RICH for +40 GeV beam triggers-No
additional cuts!
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Conclusions
• MIPP Looks forward to a productive physics run.
• The RICH as well as the other Cerenkov detectors form the bulk of the particle ID.