SciFi Tracker Beam Test outlineThe performance TOF which is needed to

Beam Test & Guide7 SimulationTOF calculation

TOF ACC estimation test for Beam Test @KEK

Atsushi Horikoshi , Osaka-U

phaseⅠ:estimate of basic SciFi tracker performance

　 particle tracking w/magnetic field , detection efficiency , high beam rate performancephaseⅡ:detailed test

　 low momentum μ(300 ～ 400MeV/c) detection, reconstruction of emittance

’05 Beam Test : SciFi Tracker test

schedule

PhaseⅠsetup （ Apr 2005 , KEK pi2 ）

5x5 hodoscpe

to estimate longitudinalμmomentum, SciFi tracker is put in magnetic field

magnetic field ： superconducting magnet , Super-JACEE(1T)

c/GeV4.0momentum directionLP:)rad(3.3P

BL

angle

LL

　　　 　

41

L

Phase Ⅰ： particle tracking in magnetic field

PhaseⅡsetup (Oct 2005 , KEK pi2)

・ μmomentum ： 300~400MeV /c・ low beam rate・ but , defuser makes many condition of beam

TOF timing resolution to devide pi & μ

π-μ 　 PID @ sigma=50ps

・ ~700MeV/c PID>3σ ( >99.7% )・ 1GeV /c PID=1.65σ ( >95% ) Phase (high rete@~1GeⅠV)　 σ<50psneeded !

π ２ beamline ： μ,e,π,p ⇒we want to select μ

momentum(MeV/c)

TD

C(n

s)

shape of TOF

400 392 133

20

80

unit : mm

・ very long light guide to avoide strong magnetic field⇒・ PMT:R6504S fine mesh PMT(used by BESS , 19DY , strong resistance of magnetic field)

S-JACEE

side view

magnetic field

@TOF PMT

３０００GAUSS

TOF shape requirement

TOF shape requirement

magnetic field @TOF PMT⇒PMT direction isparrarel to magneticfield

TOF shape requirement

magenta : scintillator length : 40cmlong light guide : 50cm

front view : isotropical position⇒same magnetic field・ long light guide : lower resolution (60ps) near to SciFi trackerIt is easy to make isotropical poistion ・ short light guide : high resolution (50ps per counter) but, design of light guide is very difficult

we selected long TOF

guide7 Simulation

timing resolutionbeam@center of counter64.59ps per PMTIf PMT resolution is same,σ(counter)=1/1.41σ(PMT)⇒45.80ps per counter

TOF & ACC estimation testπ ２ Beam Line(KEK)’05 2/1~2/7 done

define beam position of TOF・ coincidence with ref1 & ref2・ coincidence with ref1 & cuberef 1 & ref 2 : 100mm x 5mm(t)

TOF constructionscintillator & light guide is wrapped by Aluminized Mylar(50μmthin)

scintillatorEJ230(BC420)EJ204(BC404)

ACC construction

10PMTs usedacc index : 1.03

beamline setupright: ref1&ref2down:beamline setup

estimation of the resolution(preliminary)

TOF1rt-TOF1lt⇒effect of externalcounter of sigma is eliminated @ center ofcounter

σ=1.662count28.8ps/count⇒47.8psGuide 7 Simulation 45.8ps

measurement of resolution(preliminary)

)1CT(2)1T2T(2)C2T(22

1

)2TOF(

)cube(2)1TOF(2

cube)-(TOF1

)1TOF(2)2TOF(2

TOF1)-TOF2(

)cube(2)2TOF(2

cube)-(TOF2

)1ref(2)2TOF(2

ref1)-(TOF2

sigma

all plots are time walk calibrated

position dependence of resolution (preliminary)

tof2

0

20

40

60

80

100

120

-20 -10 0 10 20pos　(cm)

resolution　(ps)

tof2rtof2lweighted_mean

good resolution~ 50ps @all pos

summaryWe performed TOF & ACC estimate test

@ pi2 beam line , in feb1st~feb7thTOF timing resolution is sufficiently to distinguish pioncalculated resolution is ~ 50ps