Sampling Calorimeter

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Revision as of 17:04, 12 February 2013 by Jones (Talk | contribs) (HV control)

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Test setup

Nomenclature of the modules (could be changed)

In order to identify the different modules, the following structure is used:

X-YY-Z

with:

  • X = O (outer) or M (middle)
  • YY= 01, 02, 03, 04 ...
  • Z (only Middle modules) = A, B, C, D

HV control

  • Running HV control
    • In one terminal:
      • Login in as gep5.
      • type: "su".
      • cd to slowc/LecroyHV_Shimdir .
      • type: ./LecroyHV_Shim_LocalPerl
      • SHould connect to Lecroy crate and give the following message.
    • After LecroyHV_Shim_LocalPerl is running. In another terminal :
      • login as gep5 .
      • cd to slowc .
      • type : ./hvs BOB_TEST
      • Gui window shuold pop up.
    • Presently scintillator Top 1R, Bot 1 and Bot 2 in HV module 13 and chan 0,1,2
    • Calo blocks 1-12 in module 15 for 0-11 and blocks 13-21 in module 14 chan 0-8.
  • HV modules were tested by running -2000V across a 5 Megaohm resistor. we measured the voltage out and current out. The histogram below is the percent error in expected current values. The PDF is the charts holding the data taken during the test. Once the HV mosules are back in the TEDF another (more accurate) test may or may not be performed.


File:HV TEST2.pdf

Histogram

Light Leaks sealing

The modules were sealed from light leaks with the use of black tape. To check the sealing, the output of the PMT was measured with an micro-amperimeter, before and after the cover with tape. In top of the pipe, where the PMT is allocated, a gum stopper with slits for the cables, are placed. After many checks it was found that:

  • the main light leak come for the joint of the module with the PMT allocation pipe. (Covering it, reduce the current drain from PMT aproximatly in 1-2 orders of magnitude)
  • covering the cap of the pipe, doesn't show significant improve.
  • covering with tape the side corners of the module, the joint of the top and bottom plastic caps and the union of the pipe with the module reduce the current drain from PMT in 4-5 orders of magnitude.

Outer Modules

For the outer modules, the same PMT was used, with a voltage of 1000 V (max 1900 V) to avoid damage to the PMT.

Module Current before Current after
O-01 15.2 μA 0.3-0.2 nA
O-02 10.9 μA 0.3-0.1 nA
O-03 48.5 μA 0.7-0.5 nA
O-04 N/A 2-1.7 nA
O-05 34.4 μA 2-1.4 nA

Middle Modules

For the middle modules, the same PMT was used, with a voltage of 1000 V (max 1900 V) to avoid damage to the PMT.

Module Current before Current after
M-01-A 10.9 μA ~0.5 nA
M-01-B 24.2 μA ~0.2 nA
M-01-C 20.9 μA ~0.2 nA
M-01-D 7.5 μA ~0.2 nA
M-02-A 38.5 μA ~0.7 nA
M-02-B 13.1 μA ~0.4 nA
M-02-C 30.5 μA ~0.3 nA
M-02-D 10.7 μA ~0.2 nA
M-03-A 23.9 μA ~0.7 nA
M-03-B 6.45 μA ~0.6 nA
M-03-C 3.8 μA ~0.3 nA
M-03-D 19.2 μA ~0.3 nA
M-04-A 13.2 μA ~0.7 nA
M-04-B 6.69 μA ~0.5 nA
M-04-C 5.3 μA ~0.5 nA
M-03-D 7.8 μA ~0.45 nA

Trigger

This is the flow chart for the current trigger logic. We are using 3 scintillators; 1 double sided (2PMTs) on top, and 2 separate scintillators on bottom. The difference between threshold voltages is to match gains, this was not done by adjusting HV since presently using HV units with dual outputs for one HV setting.

Trigger Logic Chart

Scheme of cables

Scheme of the HERA-B modules. The orientation is as follows: top view with the rack modules at its left. Each module is indicated by its nomenclature (explained above), the DAQ and HV cable number (in red) and the signal cable (sgn).

Red: the number of the channel (for DAQ and HV label). Sgn: cable signal label.

Cosmic Test

  • Initial cosmic test could not have the entire calorimeter with HV since Jack has borrowed the Lecroy HV Crate.
  • Replay data
    • login as gep5, cd Desktop/eel122
    • to create root tree:
      • analyzer
      • at analyzer prompt type: decodeEel(Run number)
      • Create root tree in file eeltestrun#.root
      • then quit analyzer with: .q
  • Analyzer root tree
    • type: root eeltestrun#.root
  • Calo HV on O-01,O-02,O-03,O-04 in ADC channels 0,1,2,3
  • Scint HV on Top left, Top right, Bot 1, Bot 2 in ADC channels 24,21,23,22 for run 33 . After run 33 adc channels 8,5,7,6
  • Trigger shown above.
  • Run sheet:
Run Number Start time End time Events Calo HV Scint HV Comments
33 Fri 2-8 16:27:39 Mon 2-11 11:07:40 10593 1500, 1500, 1500, 1500 1500, 1500, 1500, 1500 No signal in ADC 22 ( Fix be replacing bad 36ns delay cable) Calo HV adc chan 0,1,2,3 (did not see 1 & 3, seems to be problem with the ADC cable move to cable with the scintillator signals and put this cable in the slot for 0-15)
34 Mon 2-11 12:04:07 crashed 9102 1500, 1500, 1500, 1500 1500, 1500, 1500, 1500 Run crashed. Found that the trigger cable has been moved ( Put it back for run 35). Calo O-01,O-02,O-03,O-04 in ADC channels 0,1,2,3 . Top 1L, Top 1R , Bot 1,Bot 2 channels 6,5,7,8. Thresholds for Top 1L, Top 1R , Bot 1,Bot 2 are 30,50,30,30 mV. Something is strange with data. Looking at Top 1L (adc[8]) see that most events are pedestal. Found that gate had been removed.
35 Tues 2-12 10:25 Tues 2-12 10:29  ? 1500, 1500, 1500, 1500 1500, 1500, 1500, 1500 Test run to see if DAQ was working
36 Tues 2-12 11:21 Tues 2-12 11:31 17431 1500, 1500, 1500, 1500 1500, 1500, 1500, 1500 Test run to check timing between ADC signal and ADC gate. Set trigger to be just Top scintillator. Put the L1A into a gate generator to get a gate width of 300ns. The gate arrived about 30ns before the ADC signal.
37 Tues 2-12 Tues 2-12 11:59  ?? 1500, 1500, 1500, 1500 1500, 1500, 1500, 1500 Placed small bottom scint on the top. Made trigger the AND between "bot 1" and "Top 1L AND 1R". ADC cable was upsidedown
38 Tues 2-12 12:00 Tues 2-12 12:14 1709 1500, 1500, 1500, 1500 1500, 1500, 1500, 1500 Placed small bottom scint on the top. Made trigger the AND between "bot 1" and "Top 1L AND 1R". ADC cable is corrected. Thresholds for Top 1L, Top 1R , Bot 1,Bot 2 are 30,50,30,30 mV.
39 Tues 2-12 12:17 Tues 2-12 12:20  ?? 1500, 1500, 1500, 1500 1500, 1500, 1500, 1500 Placed small bottom scint on the top. Made trigger the AND between "bot 1" and "Top 1L AND 1R". Thresholds for Top 1L, Top 1R , Bot 1,Bot 2 are 50,50,50,50 mV.
40 Tues 2-12 12:21 Tues 2-12 12:30  ?? 1500, 1500, 1500, 1500 1600, 1600, 1600, 1600 Placed small bottom scint on the top. Made trigger the AND between "bot 1" and "Top 1L AND 1R". Thresholds for Top 1L, Top 1R , Bot 1,Bot 2 are 50,50,50,50 mV. Top 1R peak is about 1000, top 1L has no peak. Bot 1 (adc 7) has slight overflow above 4096\
41 Tues 2-12 12:33 Tues 2-12 13:49 16969 1500, 1500, 1500, 1500 1600, 1600, 1600, 1600 Placed small bottom scint back on the bottom. Made trigger the AND between "Bot 1" and "Bot 2". Thresholds for Top 1L, Top 1R , Bot 1,Bot 2 are 50,50,50,50 mV.
42 Tues 2-12 13:57 Tues 2-12 14:02 1189 1500, 1500, 1500, 1500 1600, 1600, 1600, 1600 Placed small bottom scint back on the bottom. Made trigger the AND between "Bot 1" and "Bot 2". Thresholds for Top 1L, Top 1R , Bot 1,Bot 2 are 50,50,100,100 mV.
43 Tues 2-12 14:05 Tues 2-12 14:08 603 1500, 1500, 1500, 1500 1600, 1600, 1600, 1600 Placed small bottom scint back on the bottom. Made trigger the AND between "Bot 1" and "Bot 2". Thresholds for Top 1L, Top 1R , Bot 1,Bot 2 are 50,50,100,150 mV. Crashed when ending run.
44 Tues 2-12 14:23 CRASHED 00 1500, 1500, 1500, 1500 1600, 1600, 1600, 1600 Run crashed immeadiately upon beginning