MRPC Beam GSI Yongjie Sun University of Science and Technology of China

14th CBM collaboration meeting 2 06 Oct Index  Test setup  Preliminary results of 3 prototypes  Summary

14th CBM collaboration meeting 3 06 Oct Accelerator

14th CBM collaboration meeting 4 06 Oct Setup Our Beam Test Experiment FOPI at Cave B

14th CBM collaboration meeting 5 06 Oct m Setup Proton Beam Pb 2m 42 cm PMT 1,2 PMT 3,4 PMT 5,6 TSU MRPC USTC MRPC Platform x y

14th CBM collaboration meeting 6 06 Oct Photo of the setup

14th CBM collaboration meeting 7 06 Oct Beam Proton beam, Kinetic energy: 3.5 GeV/c

14th CBM collaboration meeting 8 06 Oct DAQ Logic TDCTDC QDCQDC PMT 1-4(5) Discriminator NIM  ECLVULOM, Logic Delay NIM  ECL LMRPC 1-6 (left) 7-12(right) FEE DelayDiscriminatorNIM  ECL Delay Gate Trigger area: 2 cm x 4 cm (without back_scint.) STOP

14th CBM collaboration meeting 9 06 Oct Index  Test setup  Preliminary results of 3 prototypes  Summary

14th CBM collaboration meeting Oct MRPC structure (endview) 5 x 250μm gaps Readout strips HV 2.5cm Readout strips: 2.5 cm x 50 cm HV electrode: Licron spray ~40 M Ω/ □ Made of window glass of 0.7 mm thick

14th CBM collaboration meeting Oct MRPC #1 (topview) 55 cm 24.1cm 2.5cm 0.6cm Gaps between strips: 0.6 cm

14th CBM collaboration meeting Oct MRPC #1 +iso-butane 5%+Freon

14th CBM collaboration meeting Oct ADC 1 ADC 2 ADC 3 ADC 4 ADC 1 ADC 2 ADC 3 ADC 4 PMT calibration ((t 3 +t 4 )-(t 1 +t 2 ))/4 Resolution~67 ps

14th CBM collaboration meeting Oct T-(t1+t2+t3+t4)/4 ADC ADC MRPC Calibration Intrinsic timing resolution = 67 ps (including momentum spread)

14th CBM collaboration meeting Oct Efficiency and resolution plateau 65 ps 97%

14th CBM collaboration meeting Oct Position scan (±7 kV) No significant efficiency drop in the gap Trigger Area: 2 cm wide From both “ charge sharing ” and cross talk.

14th CBM collaboration meeting Oct Cross Talk Trigger on the strip center: “ Cross talk ” at neighbor strips: 3% Trigger Area: 2 cm wide “ Cross talk ” at next-to- neighbor strips: ~2% Require valid TDC on two ends

14th CBM collaboration meeting Oct TDC vs. QDC Valid TDCs and valid QDCs (3 sigma above pedestal) Valid TDCs

14th CBM collaboration meeting Oct MRPC #2 (topview) Top/bottom pcb The readout strips are “ hollowed-out ” alternately. Removed: 5 mm x 4 Left: 1 mm x 5 Removed: 2.5 mm x 9 Left: 0.25 mm x 10

14th CBM collaboration meeting Oct MRPC #2 Valid TDCs and QDCs

14th CBM collaboration meeting Oct Efficiency vs. Position Valid TDCs

14th CBM collaboration meeting Oct Valid TDCs and valid QDCs (3 sigma above pedestal)

14th CBM collaboration meeting Oct MRPC #3 (topview) 55 cm 24.1cm 2.5cm 0.7cm Gaps between strips: 0.7 cm (upper part) 0.8 cm (lower part) 0.8cm

14th CBM collaboration meeting Oct MRPC #3

14th CBM collaboration meeting Oct Efficiency vs. Position Valid TDCs

14th CBM collaboration meeting Oct Summary  Three prototypes were successfully tested. Efficiency: > 97% Time resolution: ps Cross talk: < 3%  With position from silicon detectors, the data will be further analyzed. Thank you!

14th CBM collaboration meeting Oct. 2009

14th CBM collaboration meeting Oct Longitudinal

14th CBM collaboration meeting Oct Double hit