KEK Test BeamKEK Test BeamPhase I (May 2005)Phase I (May 2005)

Makoto YoshidaMakoto YoshidaOsaka Univ.Osaka Univ.

MICE-FT workshop @ DaresburyMICE-FT workshop @ DaresburyAug 30th, 2005Aug 30th, 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 muon rate in low momentum beammuon rate in low momentum beam

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 Diffuser

Super conducting solenoidSuper conducting solenoid

length1.3m

φ ８５０ mm

Super-JACEEfor balloon experiment Front view

Side view

1Tesla Magnetic field

Downstream TOF CounterDownstream TOF Counter Fine mesh PMTFine mesh PMT

R6504S ,19DYR6504S ,19DY Shape of TOF using guide7Shape of TOF using guide7

Long light guideLong light guide Magnetic field is not parallel Magnetic field is not parallel

to PMT axisto PMT axis Could cause spoil of PMT gainCould cause spoil of PMT gain

Momentum for beam testMomentum for beam test 300 – 600 MeV/c300 – 600 MeV/c

Particle identificationParticle identification 33 // separation @600MeV/c separation @600MeV/c TOF TOF < 230 ps< 230 ps

Up stream : 50psUp stream : 50ps Down stream Down stream （（ hodoscope) : 50pshodoscope) : 50ps

TOF hodoscope

Defining counter / TOF hodoscoDefining counter / TOF hodoscopepe

Defining counterinside solenoid

5x5 TOF hodoscope

TOF 1 5

TO

F 6

1

0

Test for TOF performanceTest for TOF performance

Calibrate TOF counters in 40cm x 40cm Calibrate TOF counters in 40cm x 40cm large arealarge area upstream TOF counter upstream TOF counter ~40ps~40ps 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 resolution of TOF hodoscTiming resolution of TOF hodoscopeope

3Gev/c 3Gev/c

w/o magnetic fieldw/o magnetic field (TOF8-T1)=77.3ps(TOF8-T1)=77.3ps (T1)=41.8ps(T1)=41.8ps TOFTOF)=65.0ps)=65.0ps

TOF8-T1400ps-400ps

Timing resolutionTiming resolutionin fringing magnetic fieldin fringing magnetic field

No significant loss of timing resolution in magnetic field

timing resolution of TOF

60

65

70

75

80

85

90

95

0 1 2 3 4 5 6 7 8 9 10 11

TOF number

tim

ing r

eso

luti

on

w/o magnetic fieldw/ magnetic field

Timing resolution of hodoscopeTiming resolution of hodoscope w/o magnetic fieldw/o magnetic field (hodoscope)=53.6ps(hodoscope)=53.6ps

(Average of horizontal and vertical TOF counters) -T1

σ＝ 68.0ps σ＝ 67.5ps

w/ magnetic fieldw/ magnetic field (TOFhodoscope)=53.0ps(TOFhodoscope)=53.0ps

Position dependence of TOF Position dependence of TOF resolutionresolution

w/o magnetic fieldw/o magnetic field w/ magnetic fieldw/ magnetic field

No significant position dependence : 50ps-60ps

Improvement of AerogelImprovement of Aerogel Development of ACC used for redandunt PID of e,Development of ACC used for redandunt PID of e, in SciFi tracker in SciFi tracker

test.test. Aerogel in Feb. 2005Aerogel in Feb. 2005

refractive index n=1.03refractive index n=1.03 Effective momentum range : 426 - 565MeV/cEffective 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 AerogelNew Aerogel

Adapt to low momentum m beamAdapt 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 Furthermore the Aerogel have some advantage. It is new type Aerogel

developed by Matsushita Electric Works, Ltd. and improved on transdeveloped by Matsushita Electric Works, Ltd. and improved on transparency (over 90%).parency (over 90%).

ACC performanceACC performance0.425GeV/c Negative

e

ACC light yieldACC light yield

Fit left edge of ADC distribution wFit left edge of ADC distribution with Gaussianith Gaussian tail on the right cannot be descritail on the right cannot be descri

bed by Poisson distributionbed by Poisson distribution tail could be caused by after-pulstail could be caused by after-puls

e in Fine-Mesh PMTe in Fine-Mesh PMT need to select proper gate widthneed to select proper gate width

Light yield of ACC = 32 p.e.Light yield of ACC = 32 p.e. ADC mean = 46.8ADC mean = 46.8 ADC sigma = 8.3ADC sigma = 8.3 (46.8/8.3)(46.8/8.3)22 = 32 p.e. = 32 p.e.

Performance is improved significPerformance is improved significantlyantly 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)

Cross check for ACC light Cross check for ACC light yieldyield

Npe is proportional to 1-1/Npe is proportional to 1-1/((22nn22)) Npe = 0 Npe = 0 n n22=1/=1/22

Scan beam momentum froScan beam momentum from 325 MeV/c to 450 MeV/m 325 MeV/c to 450 MeV/cc

Measured refractive index oMeasured refractive index of the ACC is 1.051f the ACC is 1.051

Our calculation in the previoOur calculation in the previous slide is confirmed to be us slide is confirmed to be validvalid

(1.051)2

1/2

22

11

nNpe

Defining counter efficiencyDefining counter efficiency

Good efficiency > 99%

40cm x 40cm

24cm x 24cm

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

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 hodoscope (average of horizontal & verticaResolution of the TOF hodoscope (average of horizontal & vertica

l) ~ 50-60ps l) ~ 50-60ps ACC (refractive index = 1.05) was testedACC (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 optimized for AutumBeam parameter was surveyed to be optimized for Autum

n beam testn beam test The effect of lead diffuser was measured, will be comparThe effect of lead diffuser was measured, will be compar

ed with simulations. ed with simulations.

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)