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Collimator scattering at JLab - link
Pre-NLCTA beam test slides from Pelle - link
Summary of results from beam test from Pelle - link
Sensor probing results in lab - link
Calibration and lab tests after pulling wirebonds from Omar - link
Simulation of beam parameters
Beam loss scenario with silicon edge hit
Intensity "per strip" (60um wide bands): 150um or 500um sigma beam spot, 50um or 500um Be exit window, 10cm or 30cm downstream of exit, Air included
10pC:
100pC:
Beam spot for one of them as example:
Beam loss scenario with direct hit
Beam parameters - 500um beam spot - 177cm & 6 foils
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Beam parameters - 150um beam spot
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Data
NLCTA runs:
/u1/software/daq/baseline_XpC_YF_ZV_HHMM.bin
X: bunch charge, Y:# foils, HHMM: time
Data taken post NLCTA in group C with same setup (cables, supplies, etc.):
Baselines:
/u1/software/daq/baseline_*V_lab_postbeam/_2/_3.bin
Calibration:
180V bias: /u1/data/SVT2014/half_module/gimp_lab_postnlcta/1/
220V bias: /u1/data/SVT2014/half_module/gimp_lab_postnlcta/2/
Log book
10/2/13
We observed that there was a new channel that had high noise after installation. It was not there during test with the source. Could be dust or a real pin hole
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10:10
Module fully installed but powered off. Out sensor is ~177cm from the exit window.
Mike setting up electron gun; some tuning is needed on the beam line since last experiment ran at 60MeV instead of 120MeV.
Noise before beam:
10:30
Beam E=119.3MeV, 50pC at gun, 10Hz
Start with 0 foils in order to search for the beam on the insertable phosphor screen.
The Phosphor screen is at ~75cm from exit window.
We use the measured voltage on the toroid located downstream of the spectrometer magnet: "ADC1".
At this point ADC1=0.06V which is ~40pC according to Mike.
10:37
Move in foils one by one and observe beam spot on phosphor screen. Picture and extracted spot size at each thickness can be seen below. The screen is about 75cm downstream of the exit window.
# foils | Tiff | FWHM |
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0 |
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1 |
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2 |
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3 |
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4 |
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5 |
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6 |
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7 |
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10:49
Lower bunch charge.
Insert 6 foils.
Still possible to see the beam on the phosphor screen but barely.
Mike estimates this to be order of 1fC/bunch.
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Runs taken, all at 6 foils:
Time | Bunch charge (pC) | ADC1 | Bias (V) | Ileak (uA) | Baseline | Baseline 180V | Comment | |||
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~11:00 | ?~0.001 | - | 180 | 10 | links | links |
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11:36 | 1.0 | 0.002 | 180 | 17 |
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| 1.0 | 0.002 | 250 | 22 | ||||||
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| 1.0 | 0.002 | 350 | 22 |
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| 1 | 0.002 | 400 | 38 |
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| 1 | 0.002 | 500 | 21 |
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12:00 | 10 | 0.01 | 180 | 6 |
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| 10 | 0.01 | 350 | 7 | |||||
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| 10 | 0.01 | 500 | 50 | |||
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| 100 | 0.135 | 180 | 7 | ||||
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| 100 | 0.135 | 250 | 6 |
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| 100 | 0.135 | 350 | 14 |
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11:36
Everything looks ok for 1pC setting.
Baseline taken at 180V, after irradiating with 1 pC at 180V:
Baseline taken at 250V, after irradiating with 1 pC at 250V:
Baseline taken at 180V, after irradiating with 1 pC at 250V:
Baseline taken at 350V, after irradiating with 1 pC at 350V:
Baseline taken at 180V, after irradiating with 1 pC at 350V:
Baseline taken at 400V, after irradiating with 1 pC at 400V:
Baseline taken at 180V, after irradiating with 1 pC at 400V:
Baseline taken at 450V, after irradiating with 1 pC at 450V:
Baseline taken at 180V, after irradiating with 1 pC at 450V:
Baseline taken at 500V, after irradiating with 1 pC at 500V:
Baseline taken at 180V, after irradiating with 1 pC at 500V:
12:00
At 10pC and 500V we observed a channel with x3 higher noise in the "weird" apv chip which looked like a pinhole candidate. However, after cycling the bias it went awayit seem to go away with lower bias voltage.
We observe a previously unseen step in the noise from 30 to 35 ADC in the middle of both working APV25. This step was turning on over a couple of channels. Not sure what this is.
Baseline taken at 180V, after irradiating with 10 pC at 180V:
Baseline taken at 350V, after irradiating with 10 pC at 350V:
Baseline taken at 180V, after irradiating with 10 pC at 350V:
Baseline taken at 500V, after irradiating with 10 pC at 500V:
Baseline taken at 180V, after irradiating with 10 pC at 500V:
12:15
Continue to 100pC and 180V.
Here we see a drastic change and what looks like many shorts has developed across the sensors. We don't see any case where the channel get a larger noise but they all go down to a level of about 20ADC.
The step in noise also become worse.
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Since we'd like to keep some channels alive we stop at this point.
Baseline taken at 180V, after irradiating with 100 pC at 180V:
Baseline taken at 250V, after irradiating with 100 pC at 250V:
Baseline taken at 180V, after irradiating with 100 pC at 250V:
Baseline taken at 350V, after irradiating with 100 pC at 350V:
Baseline taken at 180V, after irradiating with 100 pC at 350V:
10/3/13
Baseline taken at 180V in group C:
Operation
DAQ Desktop Setup
IP address: 172.27.244.72
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Keithley 2400
Manual
Serial: 9600 8N1unmigrated-wiki-markup
Common commands:
"measure?" - returns \ [voltage, current, \ ]
"source:voltage?" - returns voltage
"source:voltage 10" - set to 10 V
"output on" - output on
"output?" - returns 1 for on, 0 for off
"source:voltage:range up/down" - change range for voltage setting
BK Precision 1697
Manual
Serial:
Common commands:
"SOUT000" - enable output
"SOUT001" - disable output
"VOLT00XY.Z" - sets voltage to XY.Z Volts
Pictures
Lab prep
GIMP current vs bias
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Overview
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