KEK beam test in May KEK beam test in May 20052005

Makoto YoshidaMakoto YoshidaOsaka Univ.Osaka Univ.

MICE meeting @ FrascatiMICE meeting @ FrascatiJune 27June 27thth, 2005, 2005

ContentsContents

KEK beam test (KEK-PS T571)KEK beam test (KEK-PS T571) EquipmentsEquipments SetupSetup

TOF hodoscopesTOF hodoscopes Timing resolutionTiming resolution Operation in magnetic fieldOperation in magnetic field

Aerogel Cherenkov Counter (ACC)Aerogel Cherenkov Counter (ACC) Response for pions, muons and electronsResponse for pions, muons and electrons

Beam surveyBeam survey Focusing magnetsFocusing magnets Lead diffuserLead diffuser Intensity of low momentum muonsIntensity of low momentum muons

KEK-PS T571KEK-PS T571 May 26May 26thth – June 2 – June 2ndnd at KEK-PS at KEK-PS 2 beam line2 beam line Super-conducting solenoidSuper-conducting solenoid

1T magnetic field1T magnetic field 40cm x 40cm TOF hodoscopes40cm x 40cm TOF hodoscopes

// separation by TOF separation by TOF Momentum measurement for low momentum particlesMomentum measurement for low momentum particles

Aerogel Cherenkov counterAerogel Cherenkov counter Refractive index : 1.05Refractive index : 1.05 Discriminate Discriminate ///e by light yield in combination with T/e by light yield in combination with T

OFOF

Q3Q4

D4

SetupSetup

TOF hodoscope

Defining Counters

AerogelT12cm-thickscintillator

Defining counter efficiencyDefining counter efficiency

Good efficiency > 99%

40cm x 40cm

24cm x 24cm

Test for TOF performanceTest for TOF performance

Calibrate TOF counters in 40cm x 40cm Calibrate TOF counters in 40cm x 40cm large arealarge area Diffuser (5cm-t lead block) Diffuser (5cm-t lead block) Negative 3GeV/c (Negative 3GeV/c ()) Solenoid ON/OFFSolenoid ON/OFF

T1 5cm lead block

TOF hodoscope

~30cm

~900cm

Finger counter

Timing resolutionTiming resolutionw/ and w/o magnetic fieldw/ and w/o magnetic field

Solenoid ON

= 77psTOFcounter=65ps

Solenoid OFF

= 80psTOFcounter=68ps

The system can measure time of flight with 80ps resolutioneven in the fringe magnetic field

3GeV/c -

PMT gain variation in magnetic PMT gain variation in magnetic fieldfield

PMT number #1 - #10 for vertical#11 - #20 for horizontal

Rela

tive g

ain

(S

ole

noid

ON

/OFF)

0.91

0.99

0.95

PMTs can work in fringe field with the current setup

ACC performanceACC performance0.425GeV/c Negative

e

Focusing studyFocusing study

x= 11.5y= 10.8

x=11.9y=11.3

x=11.6y=11.0

Q=68Q4=52

Q=117Q4=161

Q=83Q4=73

Modification on focusing magnet current for 0.3GeV/c beam does not affect on beam profile so much

Q3Q4D4

Diffuser studyDiffuser studyMag. ONMag. ON Mag. OFFMag. OFF

Pb: 0Pb: 0 x : 6.6 cmx : 6.6 cmy : 6.4 cmy : 6.4 cm

9.59.5

7.17.1

Pb: 5mmPb: 5mm 10.310.3

9.49.416.316.3

13.813.8

Pb: 10mmPb: 10mm 10.910.9

10.310.318.618.6

14.914.9

Pb: 15mmPb: 15mm 11.611.6

10.710.719.019.0

15.815.8

Pb: 20mmPb: 20mm 11.611.6

10.910.921.821.8

15.815.8

Beam divergence w/o solenoid increase to ~20cm/200cm=100mrad @15mmPb

-0.3GeV/c

Muon yield in low momentum Muon yield in low momentum beambeam

-0.3GeV/c

-0.4GeV/c

5475 16min=6Hz

9000 10min=15Hz

e

TOF measurement by VME TOF measurement by VME TDCTDC

S=180ps

S=150ps

+1GeV/cTOF at center

w/o timewalkcorrection

• CAEN V1290• 25ps resolution• 16 LEMO inputs• multi-hit/multi-event buffer (32k x 32 bit)

VME ADC .vs. TDCVME ADC .vs. TDC

TOF2BTOF2A

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)

Analysis to doAnalysis to do

Extract time resolution on TOFExtract time resolution on TOF Target: 60psTarget: 60ps

70ps resolution of TOF measurement system70ps resolution of TOF measurement system Calibrate light yield in ACCCalibrate light yield in ACC Proper diffuser thickness for autumn beam testProper diffuser thickness for autumn beam test Study on track in magnetic fieldStudy on track in magnetic field

Effect on TOF measurementEffect on TOF measurement Tuning beam parametersTuning beam parameters

FocusingFocusing Muon yieldMuon yield Beam intensityBeam intensity

SummarySummary

Beam test with SC solenoid was performed at KEK-PS Beam test with SC solenoid was performed at KEK-PS 2 beam line during May 262 beam line during May 26thth – June 2 – June 2ndnd

TOF performance was checked in magnetic fieldTOF performance was checked in magnetic field Intrinsic resolution of the counter better then 70psIntrinsic resolution of the counter better then 70ps Resolution of the TOF system ~ 80psResolution of the TOF system ~ 80ps Need more careful offline workNeed more careful offline work

New ACC (refractive index = 1.05) was testedNew ACC (refractive index = 1.05) was tested good performance to discriminate good performance to discriminate ///e at 0.425GeV/c/e at 0.425GeV/c

Beam parameter was surveyed to be optimize for Autumn Beam parameter was surveyed to be optimize for Autumn beam testbeam test

The effect of lead diffuser was measured, will be comparThe effect of lead diffuser was measured, will be compared with simulations. ed with simulations.

VME ADC/TDC modules were tested to take beam dataVME ADC/TDC modules were tested to take beam data

VME ADCVME ADC

TOF2A

TOF2B

mis-configured?

T1R

T1L

Module#1 Module#2