SiPM Radiation Hardness Test

SiPM Radiation Hardness Test in Hall A

Test Plan

The Draft Test Plan to Study Radiation Damage to SiPMs in Hall A

System Diagram

The test setup for SiPM radiation hardness in Hall A during PREX experiment.

Device List

Control Computer: transversity.jlab.org: (129.57.164.28)
GPIB over IP: GPIB-ENET/100: agpib.jlab.org (129.57.192.73)
Serial Port Server: ESP904: portservha50.jlab.org (129.57.192.78)
USB over IP: AnywhereUSB/5: ausb.jlab.org (129.57.192.75)
Oscilliscope: TDS3034: dosci.jlab.org (129.57.192.77)
Power Outlet: APC Outlet Control: hlauser:hlauser@hareboot12.jlab.org (129.57.192.76)
- Outlet 1: Pulse Generator
- Outlet 2: Temperature Box
- Outlet 3: Oscilliscope
- Outlet 4: GPIB over IP
- Outlet 5: Power Supply for Hamamatsu Unit
- Outlet 6: Power Supply for SensL Unit
- Outlet 7: Picoamp Meter
- Outlet 8: Serial Port Server
USB to Serial HUB: ComHUB
- Serial 1 (COM5): Power Supply for Hamamatsu Unit
- Serial 2 (COM6): Power Supply for SensL Unit
- Serial 3 (COM7): Oscilliscope
- Serial 4 (COM8): Temperature Box
Picoamp Meter x2: Keithley-485 (GPIB)
- GPIB Address: 1 (Hamamatsu); 2 (SensL)
Pulse Generator: HP-8116A (GPIB)
- GPIB Address: 4
Power Supply x2: B&K-1787B (RS232)
Temperature Meter: CN77544 (RS232)

Power Connection and Settings

Power Cable Color Code
- Black: Ground
- Yellow: -5.0 V
- Red: +2.1 V
- Blue: Hamamatsu Bias Voltage
- Green: SensL Bias Voltage

SiPM Bias Voltage Correction vs Temperature
- Hamamatsu: 56 mV/C (70.27 at 20 C)
- SensL: 23 mV/C (28.6 at 20 C)

EPICS Variables

Hall A Beam Line IOC: iocha5.jlab.org [129.57.188.5]

hac_bcm_average: Hall A beam current (uA)

Hall A Cryo Target IOC: iocha13.jlab.org [129.57.188.29]

haBDSPOS.VAL: Hall A cryo target position (encoder value)

List of the encoder readings for the hall A cryo target

MCC general IOC: 129.57.255.4

rad44_p2: Neutron dose [mRem/hour]
rad44_p2_dose: Accumulated Neutron dose [mRem]
rad44_p1: Gamma dose [mRem/hour]
rad44_p1_dose: Accumulated Gamma dose [mRem]

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

SiPM Test in Hall A

Test Condition

Time: 04/20/2010 12:30 PM
Location: Hall A beam left
Initial Dose
- Neutron (rad44_p2) 18.4 mRem
- Gamma (rad44_p1) 61900 mRem
Radiation Chips
- Neutron Rod: serial# 2A01 close to SiPM
- TLD: serial# 9597, close to SiPM and rad44_p2
- TLD: serial# 9598, close to rad44_p1 at entrance

Pre-Test Measurement

Voltage vs Current scan done
- Hamamatsu: 20100420_132141_VICurve.txt
- Hamamatsu: 20100420_132531_VICurve.txt
- SensL: 20100420_132531_VICurve.txt
- SensL: 20100420_132531_VICurve.txt

Beam ON Test

Screenshot of SiPM performance after 50uA electron beam hits the 0.5mm Pb target

Data Set

Oscilloscope Snapshot #1: 20100420_135400_CHx.txt
Oscilloscope Snapshot #2: 20100421_014000_CHx.txt
Oscilloscope Snapshot #3: 20100421_091100_CHx.isf
Oscilloscope Snapshot #4: 20100421_182200_CHx.isf
Dataset #1: 20100420_140630.txt
- Stopped due to GIPB problem
- No production
Dataset #2: 20100420_182713.txt
- Long run with production started
- 04:13:20 - 07:19:00 oscilloscope not updating
- Stopped due to GPIB problem
Dataset #3: 20100421_091253.txt
- Stopped due to EPICS problem
Dataset #4: 20100421_105132.txt
- HV OFF at 00:07:30 to test radiation damage with bias voltage OFF
- Stopped to turn bias voltage back ON
Dataset #5: 20100421_182344.txt
- New dataset with bias voltage ON

Plots

Neutron and gamma radiation and temperature during the test

Bias voltage was adjusted based on temperature and the draw current increases rapidly with radiation.

Signal Amplitude gradually decreases as a function of radiation dose while no change of its width observed.

Some quick facts and conclusions

Hall A radiation level is extremely high during P-REX experiment: 50uA on 0.5mm Pb target (%9 radiation length)

Data Analysis

Data History

20100318 Pulse Frequency: 500 Hz
20100319 Pulse Frequency: 1.0 kHz
20100420 Voltage Current Scan