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 beforeneed two cut

Normalized NPE (hwatnkn1,2)

hwatnkn1+2 > 1.2X = 1.2

X = 0K+

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 WCEHODO

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

Coun

ter

ID

TOF

AC NPE