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KEK beam test in May 2005. Makoto Yoshida Osaka Univ. MICE meeting @ Frascati June 27 th , 2005. Contents. KEK beam test (KEK-PS T571) Equipments Setup TOF hodoscopes Timing resolution Operation in magnetic field Aerogel Cherenkov Counter (ACC) Response for pions, muons and electrons
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KEK beam test in May 2005 Makoto Yoshida Osaka Univ. MICE meeting @ Frascati June 27th, 2005
Contents • KEK beam test (KEK-PS T571) • Equipments • Setup • TOF hodoscopes • Timing resolution • Operation in magnetic field • Aerogel Cherenkov Counter (ACC) • Response for pions, muons and electrons • Beam survey • Focusing magnets • Lead diffuser • Intensity of low momentum muons
KEK-PS T571 • May 26th– June 2nd at KEK-PS p2 beam line • Super-conducting solenoid • 1T magnetic field • 40cm x 40cm TOF hodoscopes • p/m separation by TOF • Momentum measurement for low momentum particles • Aerogel Cherenkov counter • Refractive index : 1.05 • Discriminate p/m/e by light yield in combination with TOF
Q3 Q4 D4 Setup T1 2cm-thick scintillator Aerogel Defining Counters TOF hodoscope
Defining counter efficiency 40cm x 40cm 24cm x 24cm Good efficiency e > 99%
Test for TOF performance • Calibrate TOF counters in 40cm x 40cm large area • Diffuser (5cm-t lead block) • Negative 3GeV/c (p-) • Solenoid ON/OFF Finger counter TOF hodoscope 5cm lead block T1 ~30cm ~900cm
Timing resolutionw/ and w/o magnetic field 3GeV/c p- Solenoid OFF Solenoid ON • = 77ps • TOFcounter=65ps • = 80ps • TOFcounter=68ps The system can measure time of flight with 80ps resolution even in the fringe magnetic field
PMT gain variation in magnetic field 0.99 0.95 Relative gain (Solenoid ON/OFF) 0.91 PMT number #1 - #10 for vertical #11 - #20 for horizontal PMTs can work in fringe field with the current setup
ACC performance 0.425GeV/c Negative e- m- p-
Q3 Q4 D4 Focusing study Q3=83 Q4=73 Q3=68 Q4=52 Q3=117 Q4=161 sx=11.6 sy=11.0 sx= 11.5 sy= 10.8 sx=11.9 sy=11.3 Modification on focusing magnet current for 0.3GeV/c beam does not affect on beam profile so much
Diffuser study -0.3GeV/c Beam divergence w/o solenoid increase to ~20cm/200cm=100mrad @15mmPb
Muon yield in low momentum beam -0.3GeV/c 5475 m / 16min =6Hz e- p- m- -0.4GeV/c 9000 m / 10min =15Hz
TOF measurement by VME TDC • CAEN V1290 • 25ps resolution • 16 LEMO inputs • multi-hit/multi-event buffer (32k x 32 bit) +1GeV/c TOF at center S=150ps S=180ps w/o timewalk correction
VME ADC .vs. TDC • CAEN V792 • 12bit resolution • 32 inputs with 2 flat connectors • multi-event buffer (32 events) TOF2A TOF2B Something mis-configuration on the ADC module for TOF counters
Analysis to do • Extract time resolution on TOF • Target: 60ps • 70ps resolution of TOF measurement system • Calibrate light yield in ACC • Proper diffuser thickness for autumn beam test • Study on track in magnetic field • Effect on TOF measurement • Tuning beam parameters • Focusing • Muon yield • Beam intensity
Summary • Beam test with SC solenoid was performed at KEK-PS p2 beam line during May 26th– June 2nd • TOF performance was checked in magnetic field • Intrinsic resolution of the counter better then 70ps • Resolution of the TOF system ~ 80ps • Need more careful offline work • New ACC (refractive index = 1.05) was tested • good performance to discriminate p/m/e at 0.425GeV/c • Beam parameter was surveyed to be optimize for Autumn beam test • The effect of lead diffuser was measured, will be compared with simulations. • VME ADC/TDC modules were tested to take beam data
VME ADC TOF2A T1R mis-configured? TOF2B T1L Module#2 Module#1