1. Test for PMT afterpulse with He Gas Flowing
Result of SN2126
2. SN1439 under test
3. Plan
Heejong Kim

2. Afterpulse rate change of SN2126 with He Gas blowing
Stop He
Start He
for more plots

3. Change of the afterpulse timing distribution
Day 1
Day 2
Day 3
Day 4

4. Afterpulse rate of SN1439 2018-12-02
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5. Typical Timing distribution of the afterpulse(SN1439) at HV 1200V
(with respect to the leading edge of the main pulse)

6. After pulse rate as a function of main pulse(light level)

7. ADC count when there are no afterpulse timing hit in TDC

8. Pedestal level ( in ADC counts) for 4 days

9. HV dependence of the afterpulse( light level kept same)

10. Afterpulse Timing Shift as HV changes

11. Change of timing distribution as HV changes( light level kept same)
(3 pairs of arrow indicate the gate position for ADCs)

12. Gate position for 3th ADC was adjusted for HV 1200V setting

13. Plans Once PMT shows stable afterpulse rates, He Gas blowing starts.
Only He Gas will be provided.
Other type of PMT(R580 etc) will be tested.