1. KEK beam test in May 2005 Makoto Yoshida Osaka Univ. MICE meeting @ Frascati June 27 th, 2005

2. Contents KEK beam test (KEK-PS T571) KEK beam test (KEK-PS T571) Equipments Equipments Setup Setup TOF hodoscopes TOF hodoscopes Timing resolution Timing resolution Operation in magnetic field Operation in magnetic field Aerogel Cherenkov Counter (ACC) Aerogel Cherenkov Counter (ACC) Response for pions, muons and electrons Response for pions, muons and electrons Beam survey Beam survey Focusing magnets Focusing magnets Lead diffuser Lead diffuser Intensity of low momentum muons Intensity of low momentum muons

3. KEK-PS T571 May 26 th – June 2 nd at KEK-PS  2 beam line May 26 th – June 2 nd at KEK-PS  2 beam line Super-conducting solenoid Super-conducting solenoid 1T magnetic field 1T magnetic field 40cm x 40cm TOF hodoscopes 40cm x 40cm TOF hodoscopes  /  separation by TOF  /  separation by TOF Momentum measurement for low momentum particles Momentum measurement for low momentum particles Aerogel Cherenkov counter Aerogel Cherenkov counter Refractive index : 1.05 Refractive index : 1.05 Discriminate  /  /e by light yield in combination with TOF Discriminate  /  /e by light yield in combination with TOF

4. Q3 Q4 D4 Setup TOF hodoscope Defining Counters Aerogel T1 2cm-thick scintillator

5. Defining counter efficiency Good efficiency  > 99% 40cm x 40cm 24cm x 24cm

6. Test for TOF performance Calibrate TOF counters in 40cm x 40cm large area Calibrate TOF counters in 40cm x 40cm large area Diffuser (5cm-t lead block) Diffuser (5cm-t lead block) Negative 3GeV/c (   ) Negative 3GeV/c (   ) Solenoid ON/OFF Solenoid ON/OFF T1 5cm lead block TOF hodoscope ~30cm ~900cm Finger counter

7. Timing resolution w/ and w/o magnetic field Solenoid ON  = 77ps  TOFcounter=65ps Solenoid OFF  = 80ps  TOFcounter=68ps The system can measure time of flight with 80ps resolution even in the fringe magnetic field 3GeV/c  -

8. PMT gain variation in magnetic field PMT number #1 - #10 for vertical #11 - #20 for horizontal Relative gain (Solenoid ON/OFF) 0.91 0.99 0.95 PMTs can work in fringe field with the current setup

9. ACC performance 0.425GeV/c Negative   ee

10. Focusing study  x= 11.5  y= 10.8  x=11.9  y=11.3  x=11.6  y=11.0 Q  =68 Q4=52 Q  =117 Q4=161 Q  =83 Q4=73 Modification on focusing magnet current for 0.3GeV/c beam does not affect on beam profile so much Q3 Q4 D4

11. Diffuser study Mag. ON Mag. OFF Pb: 0  x : 6.6 cm  y : 6.4 cm 9.57.1 Pb: 5mm 10.39.416.313.8 Pb: 10mm 10.910.318.614.9 Pb: 15mm 11.610.719.015.8 Pb: 20mm 11.610.921.815.8 Beam divergence w/o solenoid increase to ~20cm/200cm=100mrad @15mmPb -0.3GeV/c

12. Muon yield in low momentum beam -0.3GeV/c -0.4GeV/c 5475  16min =6Hz 9000  10min =15Hz ee  

13. TOF measurement by VME TDC S=180ps S=150ps +1GeV/c TOF at center w/o timewalk correction CAEN V1290 25ps resolution 16 LEMO inputs multi-hit/multi-event buffer (32k x 32 bit)

14. VME ADC.vs. TDC TOF2B TOF2A Something mis-configuration on the ADC module for TOF counters CAEN V792 12bit resolution 32 inputs with 2 flat connectors multi-event buffer (32 events)

15. Analysis to do Extract time resolution on TOF Extract time resolution on TOF Target: 60ps Target: 60ps 70ps resolution of TOF measurement system 70ps resolution of TOF measurement system Calibrate light yield in ACC Calibrate light yield in ACC Proper diffuser thickness for autumn beam test Proper diffuser thickness for autumn beam test Study on track in magnetic field Study on track in magnetic field Effect on TOF measurement Effect on TOF measurement Tuning beam parameters Tuning beam parameters Focusing Focusing Muon yield Muon yield Beam intensity Beam intensity

16. Summary Beam test with SC solenoid was performed at KEK-PS  2 beam line during May 26 th – June 2 nd Beam test with SC solenoid was performed at KEK-PS  2 beam line during May 26 th – June 2 nd TOF performance was checked in magnetic field TOF performance was checked in magnetic field Intrinsic resolution of the counter better then 70ps Intrinsic resolution of the counter better then 70ps Resolution of the TOF system ~ 80ps Resolution of the TOF system ~ 80ps Need more careful offline work Need more careful offline work New ACC (refractive index = 1.05) was tested New ACC (refractive index = 1.05) was tested good performance to discriminate  /  /e at 0.425GeV/c good performance to discriminate  /  /e at 0.425GeV/c Beam parameter was surveyed to be optimize for Autumn beam test Beam parameter was surveyed to be optimize for Autumn beam test The effect of lead diffuser was measured, will be compared with simulations. The effect of lead diffuser was measured, will be compared with simulations. VME ADC/TDC modules were tested to take beam data VME ADC/TDC modules were tested to take beam data

17. VME ADC TOF2A TOF2B mis-configured? T1R T1L Module#1 Module#2