Detector 4

This page contains information about changes/issues for RHESSI detector 4 after the 2014 anneal. Detector updates from 2012-mid 2014 can be found here: Detector 4 anneal 2012

Notes

After the 2014 anneal, detector 4 is UNSEGMENTED.

• On May 21 starting at 19:24 UTC we raised up the Slow threshold for the Front segment.

15-141-19:24:10 start idib_chg_thrshld (4, FRONT, SLOW, 0x68)  --> Was 0x60
15-141-19:24:22 /IDPUDUMPTABL TABLE=DIBTBL4
15-141-19:24:22 /IDPUTABLE4 OFFSET=FRONTSLOWDAC
15-141-19:24:31 /IDPLOAD VALUE=0x68

• Raised front fast threshold due to elevated counts. This change reduced counts and increased livetime

2015-152-17:00:18 /IDPUTABLE4 OFFSET=FRONTFASTDAC
2015-152-17:00:31 /IDPLOAD VALUE=0x60  ; was 0x50

• On 2015 July 7, D4 front fast threshold was raised due to decreased livetime.

2015-188-18:48:17 /IDPUTABLE4 OFFSET=FRONTFASTDAC
2015-188-18:48:34 /IDPLOAD VALUE=0x70  ; was 0x60

• The front fast threshold was increased on July 10 2015 due to low livetime due to high fast rates. This action was effective in raising the livetime.

2015-191-19:21:17 /IDPUTABLE4 OFFSET=FRONTFASTDAC
2015-191-19:21:25 /IDPLOAD VALUE=0x80  ; was 0x70

• The front fast threshold was increased on July 24 2015 due to low livetime due to high fast rates. This action was effective in raising the livetime, to ~90%.

2015-205-17:22:21 /IDPUTABLE4 OFFSET=FRONTFASTDAC
2015-205-17:22:30 /IDPLOAD VALUE=0x90  ; was 0x80

D4 front slow LLD threshold history

post 2014 anneal	0x50
2015 May 21 19:24 UTC	0x70 (was 0x60)

D4 front fast LLD threshold history

post 2014 anneal	0x30
2014-Dec-8 after 22:05 UTC	0x50 (was 0x30)
2015-Jun-02 17:00:31 UTC	0x60 (was 0x50)
2015-Jul-07 18:48:34 UTC	0x70 (was 0x60)
2015-Jul-07 19:21:25 UTC	0x80 (was 0x70)
2015-Jul-24 17:22:30 UTC	0x90 (was 0x80)

D4 rear slow LLD threshold history

post 2014 anneal

0x30

D4 rear fast LLD threshold history

post 2014 anneal

0x45

D4 HV history

post 2014 anneal

4510 V