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Veto Wall Test

Hyupwoo Lee

MINERvA/Jupiter Group MeetingJune 20, 2007

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Introduction Purpose of veto wall : To exclude events which is

from impurities of neutrino beam. How? : Using a set of big scintillator panels with P

MT forward and backward(?) of main detector. My job : Test panels and PMTs and figure out the

characteristics of its signals. Since now : Examine the signals through the wave

form taken by oscilloscope.

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Contents

Position Test : Examine the changing of signals with different hit position

Timing test : Time characteristics of signal – start position of signal in time domain

Cable length test : observe the signals with different signal cable length

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Position Test Take data with only left hand side PMT Sections : row position - ½ of A and ½ of B, colu

mn position - 2, 4, 6, 8, 10, 12, 14 Averaged signal waveform of 32 events Use 2 small panels for trigger signal : same for all

the other test

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Position Test – result 1

- 60.000

- 50.000

- 40.000

- 30.000

- 20.000

- 10.000

0.000

10.000

- 150.0 - 100.0 - 50.0 0.0 50.0 100.0

Time(ns)

Voltage(m

V)

s#2

s#4

s#6

s#8

s#10

s#12

s#14

- Signal size decreases when the distance between PMT and hit position increases

- Signal seems to be delayed with the distance

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Position Test – result 2

Total charge of averaged signal

0

5

10

15

20

25

30

35

0 2 4 6 8 10 12 14 16

Section column#

Charg

e (

pC

)

- Signal size reaches over than 30pC

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Timing Test Sections : C02, C08, C14 Single sample event 2 different DAQ method

- Taking waveform from scope (25 samples for each section).- Using math func. in scope (~80 samples for each section)

3 different way used for analysis- 10% peak (signal volt) to 10% peak (trigger) : same as scope math func.- 10% of total charge (signal) to 10% peak (trigger)- 200 fC (signal) to 10% peak (trigger)

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Timing Test – result 1

- Standard deviation of timing (signal’s falling edge to trigger’s falling edge) is ~10ns

- Signals are delayed by the length between hit position and PMT.

- Scope cal. data for C14 is biased by data selection

C02 C08 C14n 25 25 25

ave 75.936 64.548 65.928std 9.460923 9.226643 10.86476

error 1.931203 1.883381 2.217759n 80 80 31

ave 75.85625 66.86088 55.73316std 9.621555 11.59667 14.60623

error 1.08251 1.304727 2.66672

C02 C08 C14n 25 25 25

ave 70.712 61.964 53.416std 9.457463 10.13044 9.473282

error 1.930496 2.067867 1.933726

C02 C08 C14n 25 25 25

ave 76.368 65.028 52.248std 8.921637 12.35993 9.2787

error 1.821121 2.522961 1.894007

scope cal.

waveform

waveform

Timing - 200fC (ns)

waveform

Timing - 10% charge (ns)

Timing - 10% peak (ns)

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Timing Test – result 2

Timing vs. section (10% charge)

40

45

50

55

60

65

70

75

0 5 10 15

Section #C{}

Tim

e inte

rval (n

s)

Timing vs. section (200fC)

40

45

50

55

60

65

70

75

80

85

0 5 10 15

Section #C{}

Tim

e inte

rval (n

s)

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Cable Length Test

Sections : C02, C08, C14 Averaged signal waveform of 256 events Signal cable length for big panel varied

with 323cm (x1, x2, x3) – using 3 same BNC cables.

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Cable Length Test – result 1

Section# : C08

- 14.000

- 12.000

- 10.000

- 8.000

- 6.000

- 4.000

- 2.000

0.000

2.000

- 200.0 - 150.0 - 100.0 - 50.0 0.0 50.0 100.0

Time(ns)

Voltage(m

V) x1

x2x3

- As cable goes longer, signals are distorted a little, but it seems OK.- As timing, shifting the signal is roughly matched with cable delay (5.5ns/m).- Roughly small signal (section #C14 – far from PMT) shows the same feature only but amplitude.

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Cable Length Test – result 2

Total charge of signal

0

5

10

15

20

25

30

35

0 0.5 1 1.5 2 2.5 3 3.5

Cable length(x323cm)

Cha

rge

(pC

)

C02C08C14

Timing (C08)

0

10

20

30

40

50

60

70

80

90

0 1 2 3 4

Cable length(x323cm)

Tim

e in

terv

al (

ns)

10% peak10% charge200fC

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Plan for Future

FEB test for veto wall Determine the setup of FEB for veto wall

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Backup 1 (sample waveform)

- 80.0

- 70.0

- 60.0

- 50.0

- 40.0

- 30.0

- 20.0

- 10.0

0.0

10.0

- 200.0 - 150.0 - 100.0 - 50.0 0.0 50.0 100.0

Time(ns)

Corr

ecte

d V

1(m

V)

Timing test

C02

sample #3

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Backup 2 (select event - scope cal.)