Detector 2

This page contains information about changes/issues for RHESSI detector 2 after the 2014 anneal. Detector updates from 2012-mid 2014 can be found here: Detector 2 anneal 2012

Notes

Detector 2 is UNSEGMENTED (no surprise there) following the 2014 anneal.

• 2014-Aug-21 Due to noise in D2, the HV was lowered by 20 counts to 4117V at 2014-233-20:41:14 UT. This was successful in quieting the noise.

• 2014-Aug-26: D2 is suffering a lot from the known light leak problem. This does not affect the quality of the data but greatly reduces livetime at times when light leaks in through the cryostat port. To alleviate this problem, the G2 front fast threshold was raised from 0x30 to 0x38 at 2014-238-19:22:56 UTC. This didn't seem to fix the problem.

• Another threshold change to try and fix the light leak issue:

 14-241-18:33:28 /IDPUTABLE2 FRONTFASTDAC
 14-241-18:33:56 /IDPULOAD VALUE=0x40     ;Front fast from 0x38 to 0x40

• Front Fast rates have become significantly worse, requested a threshold change

 14-260-16:36:36 /IDPUTABLE2 OFFSET=FRONTFASTDAC
 14-260-16:36:51 /IDPULOAD VALUE=0x50

• Front Slow Threshold was changed on May 21

15-141-19:22:50 start idib_chg_thrshld (2, FRONT, SLOW, 0x58)  --> Was 0x50
15-141-19:23:05 /IDPUDUMPTABL TABLE=DIBTBL2
15-141-19:23:05 /IDPUTABLE2 OFFSET=FRONTSLOWDAC
15-141-19:23:19 /IDPLOAD VALUE=0x58

D2 front slow LLD threshold history

post 2014 anneal	0x50
2015 May 21 19:22:50 UTC	0x58 (was 0x50)

D2 front fast LLD threshold history

post 2014 anneal	0x30
2014-08-29 19:22:56 UTC	0x38 (was 0x30)
2014-08-26 18:33:28 UTC	0x40 (was 0x38)
2014-260-16:36:51 UTC	0x50 (was 0x40)
2014-09-22 20:37:41 UTC	0x60 (was 0x50)

D2 rear slow LLD threshold history

post 2014 anneal

0x30

D2 rear fast LLD threshold history

post 2014 anneal

0x45

D2 HV history

post 2014 anneal	4510 V
2014-Aug-21 20:41:14 UTC	4117V