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Focal plane time and Cherenkov counter analysis status
HES HKS collaboration meeting3/11/2010T.Gogami
Contents
T-zero adjustmentWCACHigh current run beta
distribution
Time-zero adjustment ideally , detectors are plane Detectors have segments timing differences of each segment cable length , module propagation time
…. Need to be correct Time–zero adjustment
The ways to correct1. with t-zero counters (HTOF2Y , EHODO3)2. without t-zero counter
T-zero adjustment w/ t-zero counter
set parameters to be
T1=T2=T3=….
T1
T2
T3
t – zero counter
TOF [ns]
TOF [ns]
in the case of EHOOD2
•during experimentHES side
T-zero adjustment w/o t-zero counter
assumption
d = d’
T0
T1
T2
d d’
set parameters to be1. T0 = T1
2. (T0 = ) T1 = T2
3. (T0 = T1 = ) T2 = T3 =…
T1
1 2
•during experimentHES side (edge)HKS side•after experiment (fine tune)HES sideHKS side
HKS beta distribution
correlation is straighter in FP x vs. β - βK Kaon peak is on “0” in β - βK
HES TOF distribution
TOF resolution σ ; 460 [ps] 360 [ps]
long tale
TOF (esnt2 – esnt1)
Odd number counter’s TOF have long tale
EH1 ID – EH2 ID
TOF (esnt2 – esnt1)
EHODO2 – 17, 19, 21, 23, (25, 27, 29) are badDiscriminator ? , ECL cable ? , TDC slot?
EH1 ID – EH2 ID
EHODO hit pattern
event loss EH2 bad channel should be excepted
K+
coincidence time
K+
17 1
9212
3 25
TDC of EHODO
EHODO1
EHODO2
Coincidence time
separate clearly
Normalized NPE (hwatnkn1,2)
easier to select K+ than before
need two cut
Normalized NPE (hwatnkn1,2)
hwatnkn1+2 > 1.2X = 1.2
X = 0
K+
K+
p
p
1 dimensional cut
Xcut
β - βK
NPE time dependence (cosmic ray test)
new box 4/15/2009 –
7/1/2009 (78 days) Trigger EH1 × EH2
78 days
EHODO WC
EHODO
μ
stable
K+ NPE reduction (electron beam)1-4
1-6 1-11
1-12
2-2
2-5 2-7 2-10
39 days 63 days
39 days 63 days
NP
EN
PE
high momentum side
low momentum side
39 days 63 days
NP
E
39 days 63 days
NP
E
24 days
24 days
NPE reduction (electron beam)
teflon if so, only high momentum side
PMT thermal dependence water (chemicals … ) …. etc
reduced ~10 %
cause
AC NPE 1-dimensional cut
X
AC NPE1+2+3 < X
π
K+
X
at X = 10K+ 93 %π+ 10 %
X = 30
10Be , 40 [μA]
β - βK
π+
K+
Focal plane x vs. beta
High current run K+ beta distribution is not clear at low momentum side PMT sagging ? , TOF parameters ? , high multiplicity ?
CH2 2uA Cr 8uA
WC 1-1 & 1-2 K+ NPE distribution WC 1-1 & 1-2 K+ NPE distribution
Summary T-zero adjustment
1st fine tuned EHODO2-17 , 19 , 21 , 23 , 25 , 27 , 29 are bad should
except WC
normalized NPE survival ratio of different threshold K+ NPE reduction
AC survival ratio of different threshold
High current run beta distribution low momentum side beta is not clear at high current run
Reference plane x vs. TOF (EHODO)
selected bad counter
etimetar – erf (before after)
Coincidence time
Coincidence time
p and K+ survival ratio1-dimensional cut
WC K+ Number of photoelectron
Bucking coil recovery ratio Kaon NPENPE fit result Cosmic & HYCS
• From kaon NPE reduction parameterestimate Kaon NPE just after beam time
• ratio of expected value from cosmic ray study + HYCS
~88%
Discriminator for EHODOin the Hall
Discriminator for EHODOin counting room
T-zero adjustment of HES w/o t-zero counter
during experiment σ~420[
ps]
TOF
Cou
nte
r ID
TOF
AC NPE