Veto Wall Test

1
Veto Wall Test

• Hyupwoo Lee
• MINERvA/Jupiter Group Meeting
• June 20, 2007

2
Introduction

• Purpose of veto wall To exclude events which is
  from impurities of neutrino beam.
• How? Using a set of big scintillator panels
  with PMT 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
  waveform taken by oscilloscope.

3
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

4
Position Test

• Take data with only left hand side PMT
• Sections row position - ½ of A and ½ of B,
  column 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

5
Position Test result 1

• Signal size decreases when the distance between
  PMT and hit position increases
• Signal seems to be delayed with the distance

6
Position Test result 2

• Signal size reaches over than 30pC

7
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)

8
Timing Test result 1

• - Standard deviation of timing (signals falling
  edge to triggers 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

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Timing Test result 2
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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
- 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.
12
Cable Length Test result 2
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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)
Timing test C02 sample 3
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Backup 2 (select event - scope cal.)