pmt calibration bryan musolf. goals transform raw data into graphs for 30 pmts observe how the gain...
Post on 05-Jan-2016
216 Views
Preview:
TRANSCRIPT
PMT Calibration
Bryan Musolf
Goals
• Transform raw data into graphs for 30 PMTs
• Observe how the gain and # of photoelectrons (PE) change as a LED intensity changes
• Observe how the gain and # of PE change as high voltage changes
• Find the stable region of each PMT by analyzing the noise
• Extrapolate PMT data
• Ensure the linearity of each PMT
• Further test the PMTs
LED intensity• Increasing the LED intensity while keeping the high voltage constant
PE vs. Bias Voltage
0
20
40
60
80
100
120
140
160
180
6 8 10 12 14 16 18 20
Bias Voltage (V)
PE
PE (1000V)
PE (1100V)
PE (1200V)
Gain vs. Bias Voltage
0
2
4
6
8
10
12
14
6 8 10 12 14 16 18 20
Bias Voltage (V)
Gain (E7)
Gain (1000V)
Gain (1100V)
Gain (1200V)
As the PMTs become saturated the PE cannot be measured accurately
As the PE cannot be measured the gain is no longer constant
High Voltage• Increasing the high voltage while keeping the LED intensity constant
Noise / Gain / Spec Gain vs. High Voltage
1.00E+06
1.00E+07
1.00E+08
1.00E+09
1.00E+10
900 1100 1300 1500 1700
High Voltage (V)
Noise / Gain / Spec Gain
Gain
Spec Gain
PE vs. High Voltage
0
0.5
1
1.5
2
2.5
900 1000 1100 1200 1300 1400 1500 1600 1700 1800
High Voltage (V)
PE PE
Comparing the experimental gain vs. the specification gain from the company
Approximately1 PE should be hitting the PMT for these tests. This plot ensured that.
Noise counts / min and Extrapolation• We then added the noise counts / min to find the stable region of each
PMT• We also extrapolated the data to find the high voltage that would give
us a gain of 5E7
Noise / Gain / Spec Gain vs. High Voltage
1000
10000
100000
1E+06
1E+07
1E+08
1E+09
1E+10
1E+11
900 1100 1300 1500 1700
High Voltage (V)
Noise / Gain / Spec Gain
Noise counts / Min
Gain
Spec Gain
Extrapolation
Our gain of 5E7 is right in the stable region of the PMT
All 30 PMT• Spec gain vs. high voltage and gain vs. high voltage for all 30 PMT
Gain vs. High Voltage for all 30 PMT
1.00E+05
1.00E+06
1.00E+07
1.00E+08
1.00E+09
1.00E+10
900 1000 1100 1200 1300 1400 1500 1600 1700 1800
High Voltage (V)
Gain
PMT01
PMT02
PMT03
PMT04
PMT05
PMT06
PMT07
PMT08
PMT09
PMT10
PMT11
PMT12
PMT13
PMT14
PMT15
PMT16
PMT17
PMT18
PMT19
PMT20
PMT21
PMT22
PMT23
PMT24
PMT25
PMT26
PMT27
PMT28
PMT29
PMT30
Spec Gain vs. High Voltage for all 30 PMT
1.00E+05
1.00E+06
1.00E+07
1.00E+08
1.00E+09
1.00E+10
900 1000 1100 1200 1300 1400 1500 1600 1700 1800
High Voltage
Spec Gain
PMT01
PMT02
PMT03
PMT04
PMT05
PMT06
PMT07
PMT08
PMT09
PMT10
PMT11
PMT12
PMT13
PMT14
PMT15
PMT16
PMT17
PMT18
PMT19
PMT20
PMT21
PMT22
PMT23
PMT24
PMT25
PMT26
PMT27
PMT28
PMT29
PMT 30
Our measured gain closely reflects the spec gain given to us by the company
Gain plot starts to break down when PMTs start to become saturated
All 30 PMT• Noise vs. high voltage and the extrapolation for all 30 PMT
Noise / min vs. High Voltage for all 30 PMT
100
1000
10000
100000
1000000
10000000
100000000
900 1100 1300 1500 1700
High Voltage (V)
Noise Counts / min
PMT01PMT02PMT03PMT04PMT05PMT06PMT07PMT08PMT09PMT10PMT11PMT12PMT13PMT14PMT15PMT16PMT17PMT18PMT19PMT20PMT21PMT22PMT23PMT24PMT25PMT26PMT27PMT28PMT29PMT30
Extrapolation vs. High Voltage
1.00E+05
1.00E+06
1.00E+07
1.00E+08
1.00E+09
1.00E+10
1.00E+11
1.00E+12
900 1000 1100 1200 1300 1400 1500 1600 1700 1800
High Voltage
Extrapolation
PMT01
PMT02
PMT03
PMT04
PMT05
PMT06
PMT07
PMT08
PMT09
PMT10
PMT11
PMT12
PMT13
PMT14
PMT15
PMT16
PMT17
PMT18
PMT19
PMT20
PMT21
PMT22
PMT23
PMT24
PMT25
PMT26
PMT27
PMT28
PMT29
PMT30
We have some very nice PMTs!!
The extrapolation data will allow us to set high voltages to get specific gains
All 30 PMT• Gain / Spec gain / Noise layered
Gain / Spec Gain / Noise vs. High Voltage
1.00E+03
1.00E+04
1.00E+05
1.00E+06
1.00E+07
1.00E+08
1.00E+09
1.00E+10
1.00E+11
900 1000 1100 1200 1300 1400 1500 1600 1700 1800High Voltage (V)
Gain / Spec Gain / Noise
Gain01 Gain02
Gain03 Gain04
Gain05 Gain06
Gain07 Gain08
Gain09 Gain10
Gain11 Gain12
Gain13 Gain14
Gain15 Gain16
Gain17 Gain18
Gain19 Gain20
Gain21 Gain22
Gain23 Gain24
Gain25 Gain26
Gain27 Gain28
Gain29 Gain30
Spec01 Spec02
Spec03 Spec04
Spec05 Spec06
Spec07 Spec08
Spec09 Spec10
Spec11 Spec12
Spec13 Spec14
Spec15 Spec16Spec17 Spec18
Spec19 Spec20
Spec21 Spec22
Spec23 Spec24
Spec25 Spec26
Spec27 Spec28
Spec29 Spec30
Noise01 Noise02
Noise03 Noise04
Noise05 Noise06
Noise07 Noise08
Noise09 Noise10
Noise11 Noise12
Noise13 Noise14
Noise15 Noise16
Noise17 Noise18
Noise19 Noise20
Noise21 Noise22
Noise23 Noise24
Noise25 Noise26
Noise27 Noise28
Noise29 Noise30
Further testing• We found that some of the PMT bases were broken and
needed to be repaired
• In particular, R1 seemed to be the problem on most
Further Testing• After fixing the bases we needed to make sure the PMT
bases could withstand the LAr we would be using them in
Further Testing• We also needed to make some splitters so we could
connect the PMTs to a high voltage source and an oscilloscope to take measurements
Needless to say, I got a little bit more efficient!
Further Testing
• We ran one test in liquid nitrogen
• Everything held up and we got a nice signal
• Testing in liquid nitrogen or LAr will be ready soon
top related