Detector 7

From RHESSI Wiki

This page contains information about changes/issues for RHESSI detector 7 after the 2014 anneal. Detector updates from 2012-mid 2014 can be found here: Detector 7 anneal 2012

Contents 1 Post 2014 Anneal 2 Post 2016 Anneal 3 D7 front slow LLD threshold history 4 D7 front fast LLD threshold history 5 D7 rear slow LLD threshold history 6 D7 rear fast LLD threshold history 7 D7 HV history

Post 2014 Anneal

After the 2014 anneal, detector 7 was unsegmented. As of 11-27-2014 it has SEGMENTED

• A tweak shortly after the anneal was completed:

 G7 front slow to 0x80 (was 0x70) after 03:40 on 2014-Aug-14.

• 11-27-2014. G7 rear slow rates rose and the detector segmented

• Front Fast and Front Slow thresholds were changed on January 7, 2015 at 14:20 UTC to default values. Front slow is showing very high values on the monitor rates (~900).

 G7 front slow to 0x0C (was 0x10) after 14:21 on 2015-Jan-07.
 G7 front fast to 0x22 (was 0x2E) after 14:22 on 2015-Jan-07.

• On Jan 13 2015, we reverted the front slow thresh back to its previous value, because it was suspected that low-energy D7 events were filling up the SSR.

 15-013-19:27:21 /IDPUTABLE7 OFFSET=FRONTSLOWDAC
 15-013-19:27:36 /IDPULOAD VALUE=0x10 ; increased from 0x0C
 15-013-19:28:17 start idpu_dec_active_vigorous

• The rear fast threshold was changed on July 13 2015 due to dropping livetime in the rear:

2015-194-16:35:07 /IDPUTABLE7 OFFSET=REARFASTDAC
2015-194-16:35:15 /IDPLOAD VALUE=0x50 ; was 0x45

• The rear fast threshold was changed on July 24 2015 due to low livetime. However, the change probably wasn't needed; the tohban hadn't noticed that a change had already been made a few days ago. The next tohban can reverse the change if desired.

2015-205-17:19:59 /IDPUTABLE7 OFFSET=REARFASTDAC
2015-205-17:20:08 /IDPLOAD VALUE=0x70 ; was 0x60

• On August 27 D7 rear fast threshold was rasied to increase its livetime.

2015-239-17:58:24 /IDPUTABLE7 OFFSET=REARFASTDAC
2015-239-17:58:32 /IDPLOAD VALUE=0x80 ; was 0x70

• On October 8, 9, and 12, the rear fast threshold was raised three times to try and raise livetime. Results still need to be assessed.

2015-281-21:57:30 /IDPUTABLE7 OFFSET=REARFASTDAC
2015-281-21:57:39 /IDPLOAD VALUE=0xB0 ; was 0xA0

2015-282-19:56:31 /IDPUTABLE7 OFFSET=REARFASTDAC
2015-282-19:57:41 /IDPLOAD VALUE=0xC0 ; was 0xB0

2015-285-21:51:54 /IDPUTABLE7 OFFSET=REARFASTDAC
2015-285-21:52:03 /IDPLOAD VALUE=0xD0 ; was 0xC0

• Also on October 12, the front fast threshold on D7 (and also D1) was raised. This is to try and top off the livetime used in the attenuator logic. It might not work, since the fast rates are not terribly high for this detector, in which case the change could be reversed by a future tohban. Check this and see..

2015-285-21:50:47 /IDPUTABLE7 OFFSET=FRONTFASTDAC
2015-285-21:50:56 /IDPLOAD VALUE=0x50  ; was 0x40

• On November 6 and 7, the rear fast threshold was raised twice to try and raise livetime. No luck.

2015-312-06:17:07 /IDPUTABLE7 OFFSET=REARFASTDAC
2015-312-06:17:16 /IDPLOAD VALUE=0xF0 ; wax 0xE0

2015-313-19:22:31 /IDPUTABLE7 OFFSET=REARFASTDAC
2015-313-19:22:41 /IDPLOAD VALUE=0xFF ; was 0xF0

• November 14, HV dropped by 200V to 3897V

2015-318-07:02:08 /ihvdac detector=7, voltage=201

• November 25, 2015, HV dropped to 3504V and front slow threshold raised to 0x30

2015-329-21:24:47 /IDPUTABLE7 OFFSET=FRONTSLOWDAC
2015-329-21:24:59 /IDPLOAD VALUE=0x30  ; was 0x10

2015-330-00:27:47 /ihvdac detector=7, voltage=181 (3504 V)

• 2015 December 10: front-slow threshold lowered

2015-344-21:38:17 /IDPUTABLE7 OFFSET=FRONTSLOWDAC
2015-344-21:38:33 /IDPLOAD VALUE=0x10  ; was 0x20

• 2015 December 12: HV lowered by 200 V in an attempt to reduce enhanced fast rates and livetime of D7 "REAR". The rear fast threshold is already at 0xFF. So this HV was done as a desperate measure.

2015-346-00:33:57 /IHVDAC DETECTOR=7, VOLTAGE=171 ; ~3300 V

• 2015 December 12: front-slow threshold raised because the previous change on December 10 led to a significant increase of slow rates

2015-346-19:20:04 /IDPUTABLE7 OFFSET=FRONTSLOWDAC
2015-346-19:20:21 /IDPLOAD VALUE=0x20  ; was 0x10

• On January 27 the slow front threshold was changed from 0x20 to 0x10. After the change a huge number of slow counts were observed, so it was decided to restore the previous slow front threshold value of 0x20.

2016-027-20:14:38 /IDPUTABLE7 OFFSET=FRONTSLOWDAC
2016-027-20:14:47 /IDPLOAD VALUE=0x10  ; was 0x20

2016-027-20:15:35 /IDPUTABLE7 OFFSET=FRONTSLOWDAC
2016-027-20:15:44 /IDPLOAD VALUE=0x20  ; was 0x10

Post 2016 Anneal

• 2016 April 27 (DOY 118) started turning on D1. HV reached 3995 V by April 29, ~03:40

16-119-00:49:49 start ihv_ramp_stage1_g1_g4_g7 (HV = 0x0A, ~200 V)
16-119-02:27:48 start ihv_ramp_stage2_g1_g4_g7 (HV = 0x33, 980 V)
16-119-04:08:00 start ihv_ramp_stage3_g1_g4_g7 (HV = 0x67, 1985 V)
16-120-00:22:16 start ihv_ramp_stage4_g1_g4_g7 (HV = 0x9A, ~3000 V)
16-120-02:01:36 start ihv_ramp_stage5_g1_g4_g7 (HV = 0xB3, ~3500 V)
16-120-03:41:12 start ihv_ramp_stage6_g1_g4_g7 (HV = 0xCE, 3995 V)

• 2016 April 29, Front fast and front-slow thresholds were raised to 0x50 and 0x70, respectively.

16-120-00:28:44 /IDPUTABLE7 OFFSET=FRONTFASTDAC
16-120-00:28:58 /IDPLOAD VALUE=0x30

16-120-02:05:44 /IDPUTABLE7 OFFSET=FRONTFASTDAC
16-120-02:06:04 /IDPLOAD VALUE=0x40

16-120-22:22:59   /IDPUTABLE7 OFFSET=FRONTFASTDAC
16-120-22:23:08   /IDPLOAD VALUE=0x50  ; was 0x40


16-120-03:46:13 /IDPUTABLE7 OFFSET=FRONTSLOWDAC
16-120-03:46:23 /IDPLOAD VALUE=0x40

16-120-03:47:31 /IDPUTABLE7 OFFSET=FRONTSLOWDAC
16-120-03:47:40 /IDPLOAD VALUE=0x60

16-120-23:56:53 /IDPUTABLE7 OFFSET=FRONTSLOWDAC
16-120-23:57:03 /IDPLOAD VALUE=0x70

D7 front slow LLD threshold history

post 2014 anneal	0x70
2014-Aug-14 after 03:40 UTC	0x80 (was 0x70)
2014-Dec-4 after 01:09 UTC	0x10 (was 0x80)
2015-Jan-07 after 14:09 UTC	0x0C (was 0x10)
2015-Jan-14 19:27:36 UTC	0x10 (was 0x0C)
2015-Nov-25 21:24:47 UTC	0xC0 (was 0x30)
2015-Dec-10 21:38:33 UTC	0x10 (was 0x20)
2015-Dec-12 19:20:21 UTC	0x20 (was 0x10)
2016-Jan-27 20:14:47 UTC	0x10 (was 0x20)
2016-Jan-27 20:15:44 UTC	0x20 (was 0x10)
post 2016 anneal	0x70

D7 front fast LLD threshold history

post 2014 anneal	0x2E
2015-Jan-07 after 14:09 UTC	0x22 (was 0x2E)
2015-May-12 21:01:53	0x30 (was 0x22)
2015-May-12 21:03:20	0x40 (was 0x30)
2015-Oct-12 21:50:56	0x50 (was 0x40)
2015-12-17 20:29:46	0x60 (was 0x50)
post 2016 anneal	0x50

D7 rear slow LLD threshold history

post 2014 anneal	0x30
post 2016 anneal	0x30

D7 rear fast LLD threshold history

post 2014 anneal	0x45
2015-Jul-13 16:35:15	0x50 (was 0x45)
2015-Jul-24 17:20:08	0x70 (was 0x60)
2015-Aug-27 17:58:32	0x80 (was 0x70)
2015-Sep-17 06:37:46	0x90 (was 0x80)
2015-Sep-21 20:10:26	0xA0 (was 0x90)
2015-Oct-08 21:57:39	0xB0 (was 0xA0)
2015-Oct-09 19:57:41	0xC0 (was 0xB0)
2015-Oct-12 21:52:03	0xD0 (was 0xC0)
2015-Nov-06 06:17:16	0xF0 (was 0xE0)
2015-Nov-07 19:22:41	0xFF (was 0xF0)
??	0x45

D7 HV history

post 2014 anneal	4510 V
2015-11-14 07:02:08 UTC	3897 V (was 4094)
2015-11-26 00:27:47 UTC	3504 V (was 3897)
2015-12-12 00:33:57 UTC	3300 V (was 3504)
post 2016 anneal	3995 V
??	0V