A.Olchevski, JINR (Dubna) Test Beam studiesof COMPASS ECAL0 Test Beam studies of COMPASS ECAL0 module prototype with MAPD readout ECAL0 Team, JINR, DUBNA

A.Olchevski, JINR (Dubna) Possible view of ECAL0: sizes: ~ 360x360 cm 2 with central hole ~ 120x120 cm 2 length: ~ cm modules: 800 with size 12x12 cm 2 (“shashlyk”) MAPDs: ~9300 ( Multipixel Avalanche PhotoDiode) for inner part: 16 MAPDs per module for outer part: 9 MAPDs per module Possible view of ECAL0: sizes: ~ 360x360 cm 2 with central hole ~ 120x120 cm 2 length: ~ cm modules: 800 with size 12x12 cm 2 (“shashlyk”) MAPDs: ~9300 ( Multipixel Avalanche PhotoDiode) for inner part: 16 MAPDs per module for outer part: 9 MAPDs per module

A.Olchevski, JINR (Dubna) Since 1989 many GM APD structures were developed by different developers: CPTA/Photnique(Moscow/Geneva) ~1000 pixels/mm Zecotek(Singapore, Dubna) up to 40000pixels/mm MEPhI/Pulsar (Moscow) ~1000 pixels/mm Hamamatsu Photonics (Hamamatsu, Japan) up to 1600 pixel/mm SensL(Cork, Ireland) RMD (Boston) MPI Semiconductor Laboratory (Munich, Germany) FBK-irst(Trento, Italy) ……Every producer invented their own name for this device:MRS APD, MAPD, SiPM, SSPM, SPM, G-APD … MAPD Developers and producers

A.Olchevski, JINR (Dubna) ZECOTEK: MAPD-3A /mm 2 MAPD-3B / mm 2 MAPD Stucture

A.Olchevski, JINR (Dubna) Characterics of MAPD

A.Olchevski, JINR (Dubna) high number of pixels ~ ( 3x3 mm 2 ) work at low bias voltage (<70 V), PDE ~12 %( 520 nm) (Photon Detection Efficiency) Gain ~3x10 4 Temperature dependences ~ 3% insensitive to magnetic fields up to 15 T, compact, rugged and show no aging* tolerate accidental illumination radiation hardness (>10 12 p/cm 2 ) * Capacitance ~ 300pF Problems: recovery time, temperature dependence dependence gain vs voltage Gain and PDE * under study Characterics of MAPD

A.Olchevski, JINR (Dubna) 3 type modules: - sampling 4mmSc/4 mm Pb, 96x96 mm 2, 36 fibers, 6ch-s (~10-11 % sampling ) - sampling 4mmSc/2 mm Pb, 12.12x12.12 cm 2, 64 fibers(32 loops), 1 tower,4 bandles, D b = 6 mm - sampling 4mmSc/2 mm Pb, 4.04x4.04cm 2, 144 fibers(72 loops), 9 tower, D b = 6 mm (~7%) Goals of the measurements - Resolution vs energy - Compare results with MAPD and PM - Number of photoelectrons - Temperature stabilization - Calibration by LED (monitored by pin diode) - Optimization of module structure BEAM test at PS (T9)

A.Olchevski, JINR (Dubna) Light guide - cone D 1 / D 2 = 6/4.4 K PM =0.54 K Ampd/PM =0.6

A.Olchevski, JINR (Dubna) Setup at Beam test atT9

A.Olchevski, JINR (Dubna) FEE – fast preamplifier, G=14 Trigger – COMPASS( Munich, Protvino) DAQ – VME CAEN V792AC Charge ADC 32 Ch ( SADC Option) Temperature stabilization - Peltier cooler with fan (working point 15 o o )* Calibration – Led, controlled by Pin Diode *The method of gain stabilization by using feedback with HV is possible, but noise increase with T (2 times/ 9 degree) Read Out

A.Olchevski, JINR (Dubna) Response 1 tower modules at 4 GeV 1 ch= 5.24 Phe 1 ch=2.00 Phe

A.Olchevski, JINR (Dubna) Stability

A.Olchevski, JINR (Dubna) Response vs Beam Intensity

A.Olchevski, JINR (Dubna) Response & resolution vs Beam Energy Response & resolution of PM Response & resolution of AMPD Threshold estimation of AMPD 3σ ped =30ch-> 60 phe -> ~75 MeV

A.Olchevski, JINR (Dubna) Response & resolution vs Beam Energy

A.Olchevski, JINR (Dubna)

- Long term stability - Temperature stabilization for the 9 tower module - Test with COMPASS DAQ& SADC - Tests in muon beam during the COMPASS GPD run to work in real background condition - Tests in 2009 with High Energy Beam H2. Uniformity - Continue collaboration with Zecotek firm ( increase the gain, size, PDE and decrease recovery time) Plans

A.Olchevski, JINR (Dubna) Acknowledgements Appreciate very much important opportunity of T9 facility. Thanks to Lau Gatignon for very good beam quality & support. We gratefully acknowledge the support of the Protvino and Munich groups for presented equipment and readout electronics. We also thank G.Mallot and A.Magnon for help and support. Special thanks are due to V.Anosov and V. Pessaro for technical assistance.