1. KEK Test Beam Phase I (May 2005) Makoto Yoshida Osaka Univ. MICE-FT workshop @ Daresbury Aug 30th, 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 muon rate in low momentum beam muon rate in low momentum beam

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 Diffuser

5. Super conducting solenoid length 1.3m φ ８５０ mm Super-JACEE for balloon experiment Front view Side view 1Tesla Magnetic field

6. Downstream TOF Counter Fine mesh PMT Fine mesh PMT R6504S,19DY R6504S,19DY Shape of TOF using guide7 Shape of TOF using guide7 Long light guide Long light guide Magnetic field is not parallel to PMT axis Magnetic field is not parallel to PMT axis Could cause spoil of PMT gain Could cause spoil of PMT gain Momentum for beam test Momentum for beam test 300 – 600 MeV/c Particle identification Particle identification 3   /  separation @600MeV/c  TOF < 230 ps Up stream : 50ps Down stream （ hodoscope) : 50ps TOF hodoscope

7. Defining counter / TOF hodoscope Defining counter inside solenoid 5x5 TOF hodoscope TOF 1  5 TOF 6  10

8. Test for TOF performance Calibrate TOF counters in 40cm x 40cm large area Calibrate TOF counters in 40cm x 40cm large area upstream TOF counter  ~40ps upstream TOF counter  ~40ps 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

9. Timing resolution of TOF hodoscope 3Gev/c   3Gev/c   w/o magnetic field w/o magnetic field  (TOF8-T1)=77.3ps  (TOF8-T1)=77.3ps  (T1)=41.8ps  (T1)=41.8ps   TOF  )=65.0ps   TOF  )=65.0ps TOF8-T1 400ps -400ps

10. Timing resolution in fringing magnetic field No significant loss of timing resolution in magnetic field

11. Timing resolution of hodoscope w/o magnetic field w/o magnetic field  (hodoscope)=53.6ps  (hodoscope)=53.6ps (Average of horizontal and vertical TOF counters) -T1 σ ＝ 68.0psσ ＝ 67.5ps w/ magnetic field w/ magnetic field  (TOFhodoscope)=53.0ps  (TOFhodoscope)=53.0ps

12. Position dependence of TOF resolution w/o magnetic field w/o magnetic field w/ magnetic field w/ magnetic field No significant position dependence : 50ps-60ps

13. Improvement of Aerogel Development of ACC used for redandunt PID of e,  in SciFi tracker test. Development of ACC used for redandunt PID of e,  in SciFi tracker test. Aerogel in Feb. 2005 Aerogel in Feb. 2005 refractive index n=1.03 refractive index n=1.03 Effective momentum range : 426 - 565MeV/c Effective momentum range : 426 - 565MeV/c Npe was measured to be 18 p.e for electrons. Npe was measured to be 18 p.e for electrons. New Aerogel New Aerogel Adapt to low momentum m beam Adapt to low momentum m beam The Aerogel (index = 1.05) was selected in May,2005. The Aerogel (index = 1.05) was selected in May,2005.  PID in the range of 328 - 434MeV/c is possible.  PID in the range of 328 - 434MeV/c is possible. Furthermore the Aerogel have some advantage. It is new type Aerogel developed by Matsushita Electric Works, Ltd. and improved on transparency (over 90%). Furthermore the Aerogel have some advantage. It is new type Aerogel developed by Matsushita Electric Works, Ltd. and improved on transparency (over 90%).

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

15. ACC light yield Fit left edge of ADC distribution with Gaussian Fit left edge of ADC distribution with Gaussian tail on the right cannot be described by Poisson distribution tail on the right cannot be described by Poisson distribution tail could be caused by after- pulse in Fine-Mesh PMT tail could be caused by after- pulse in Fine-Mesh PMT need to select proper gate width need to select proper gate width Light yield of ACC = 32 p.e. Light yield of ACC = 32 p.e. ADC mean = 46.8 ADC mean = 46.8 ADC sigma = 8.3 ADC sigma = 8.3 (46.8/8.3) 2 = 32 p.e. (46.8/8.3) 2 = 32 p.e. Performance is improved significantly Performance is improved significantly Feb. 2005: 18 p.e. (n=1.03) Feb. 2005: 18 p.e. (n=1.03) May 2005: 32 p.e. (n=1.05) May 2005: 32 p.e. (n=1.05)

16. Cross check for ACC light yield Npe is proportional to 1- 1/(  2 n 2 ) Npe is proportional to 1- 1/(  2 n 2 ) Npe = 0  n 2 =1/  2 Npe = 0  n 2 =1/  2 Scan beam momentum from 325 MeV/c to 450 MeV/c Scan beam momentum from 325 MeV/c to 450 MeV/c Measured refractive index of the ACC is 1.051 Measured refractive index of the ACC is 1.051 Our calculation in the previous slide is confirmed to be valid Our calculation in the previous slide is confirmed to be valid (1.051) 2 1/  2

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

18. 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

19. 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

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

21. 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 hodoscope (average of horizontal & vertical) ~ 50-60ps Resolution of the TOF hodoscope (average of horizontal & vertical) ~ 50-60ps ACC (refractive index = 1.05) was tested 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 optimized for Autumn beam test Beam parameter was surveyed to be optimized 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.

23. 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)

24. 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)