SiPM Test Log

Event Log

2010 Mar 17

Photos of SiPM test setup.

Location of the SiPM Box

Close view of SiPM test setup

Distance between SiPM and Hall A Target

All Hardware intrustruments have been connected.
The SiPM box is put on top of the cryo target parking support which is at about 135 degrees to the left side of the beam and 20 meters away from the target.
The real time neutron counter is put right next to the SiPM.

2010 Mar 18

Have all the remote communication working properly.
Other than the oscilloscope, Labview programs to all the rest devices are ready.
Did first measurement of the correlation between the draw current and the bias voltage.

Hamamatsu SiPM Draw Current vs Bias Voltage

SensL SiPM Draw Current vs Bias Voltage

Signals on Oscilloscope with 70.5V on Hamamatsu and 28.5V on SensL are shown as well.

Signals on Oscilloscope with 70.5V on Hamamatsu and 28.5V on SensL

2010 Mar 19

Finished Oscilloscope initialization program, the readback program is done as well but not quite stable
Increase the pulse frequency to 1.0 kHz, here is the final configuration for the pulse generator

* Direct DC couple to the LED
* Frequency: 1.0 kHz
* Width: 8.0 ns
* High Level: 5.0 V
* Low Level: 0.0 V

Tested the draw current corresponding to the voltage level and recorded the oscilloscope signals (average of 128 waveforms)
Removed both SiPMs from the box for Hall closing.

SiPM signal shape vs bias voltage

Signal shapes from Hamamatsu SiPM with different bias voltage.

Signal shapes from SensL SiPM with different bias voltage.

Draw current vs bias voltage

Hamamatsu SiPM draw current as a function of bias voltage.

SensL SiPM draw current as a function of bias voltage.

SiPM signal amplitude vs draw current as a function of bias voltage. From the plots, we can have some sense of the signal to background ratio.

2010 Mar 21

Finished first version of the Central Control VI, change all serial communication timeout to be 1 second
Stress test

2010 Mar 22

Stress test failed, system won't run VI after rebooting. Maybe it's time to rebuilt the XP system on the computer

2010 Mar 23

Brought transversity.jlab.org to CC for a system rebuilt
At the mean time, upgraded the Central Control VI to version 2 with a more responsive interface and better timing control.

2010 Mar 24

CC rebuilt the XP System
Installed all necessary software, all devices are up and running well
Changed GPIB timeout to be 1 second, should not have any timeout problem
Stress test with Central Control VI without writing file to the disk :S

A screen shot of Central Control VI

2010 Mar 25

Modified the algorithm to initialize the VISA resource.
New stress test passed 30000 readings!!!!

2010 Mar 26

AGPIB and DOSCI lost connection at around 12:30AM when MCC tuning beam in the Hall. Rebooting solved the problem. More shielding may be required.

2010 Mar 29

Added additional shielding in front of the instruments

2010 Mar 31

EPICS readout configured

2010 Apr 1

Updated Control VI to v4 with intregrated EPICS readout

The V4 Labview control VI with EPICS variables.

2010 Apr 5

Updated Control VI to v5, new features added
- independent readouts from GPIB, Serial and EPICS
- added communication status indications
- added plot history feature

2010 Apr 6

Calibrated RTD temperature sensor using an ice-water mix
Offset is 0.185 +- 0.005 degrees
Therefore, nominal temperature in Hall A is 21.0 degree, so the bias voltages for two SiPMs are:
- 70.33 V for Hamamatsu
- 28.62 V for SensL

2010 Apr 7

Added Temperature Feedback to Bias Voltage
- Temperature averaged over 10 minutes, statistical fluctuation < 0.01 degrees
- Voltage adjust step: 1 mV
- Voltage_Hamamatsu = 70.27 + 0.056*(T-20)
- Voltage_SensL = 28.6 + 0.023*(T-20)

The V5 Labview control VI with EPICS variables.

2010 Apr 16

Hall A finally took the first production run

2010 Apr 18

The Hamamatsu power supply lost communication. Could not be fixed through multiple remote reboot. Probably caused by radiation damage :S
The neutron dose meter can only read 3 digit, once the reading is over 100000, it won't be very easy to accurately trace the dose, needs to be reset.

2010 Apr 20

Neutron probe has been reset
Test in Hall A started from 18:00

2010 Apr 22

Beam stopped at 09:00
Test in Hall A finished at 09:00
Draw current: 200 uA for Hamamatsu and 1600 uA for SensL
Leave the all the instruments in tunnel with temperature about 21 C

2010 May 4

Move all the instruments to ARC Room 628 at 15:00
Room Temperature at Room 628 is about 22 C

2010 May 5

Started Annealing test from 18:00 in Room 628
Draw current: 135 uA for Hamamatsu and 1120 uA for SensL, both get lowered

early test data

20100318 Pulse Frequency: 500 Hz
20100319 Pulse Frequency: 1.0 kHz