RHESSI Attenuator State Record

The RHESSI attenuators are two sets of aluminum disks that can be brought into the field of view of the detectors to prevent saturation during the largest flares. There is a thin set of disks that provide modest attenuation and a thicker set for the very largest flares. Both have a small thin spot in the middle to allow at least some response down to the lowest energies. The attenuator states referred to in the table are: 0=both attenuators out; 1=thin in, thick out; 2=thick in, thin out; 3=both in. RHESSI was launched in attenuator state 1, which has been its primary mode of operation during the early-orbit period.

Each line in the table represents actions taken during a single satellite contact with the Berkeley Ground Station. When the state was changed several times during a contact, the states are shown in order (not including the initial state before commanding, which will be the same as the last state of the previous entry). Times are approximate times for the pass, so the moment of motion can be anywhere within about 10 minutes of the time shown. More precise times are available if needed -- see the contact information below.

Starting March 6, 2002, we have been refining an algorithm to bring the thin shutter in and out automatically in response to count rates. In the code below, "A01" refers to an automatic mode to switch between states 0 and 1, "A13" goes between states 1 and 3, "A013" can automatically go to any of the three states depending on the flare evolution. These automated states spend most of their time in their lowest (most open) state except when a bright flare is active (usually M class or higher). Individual shutter motions while in an automated mode are not listed here. The instantaneous shutter state can be read from the raw data, and will eventually also be available from the quicklook data.

YEARMONTHDAYHOURMINUTEAttenuator state(s)
2002 02 14 22 020
2002 02 14 23 441
2002 02 17 00 040
2002 02 17 01 401
2002 02 18 17 290
2002 02 18 20 501
2002 02 18 22 350
2002 02 19 00 201
2002 02 23 19 550
2002 02 23 21 351
2002 02 26 16 503-2-0-1-0
2002 02 26 21 551
2002 02 28 20 250
2002 02 28 22 101
2002 03 01 17 150-1-0
2002 03 01 20 381
2002 03 04 17 400
2002 03 06 16 15A01
2002 03 07 17 591
2002 03 12 08 30A01
2002 03 14 07 001
2002 03 21 06 10A13
2002 03 27 01 500
2002 03 27 08 33A13
2002 03 28 00 150
2002 03 28 07 00A13
2002 03 29 02 003-1-0-A013
2002 03 31 23 001
2002 04 01 04 05A13
2002 04 11 05 580
2002 04 11 07 401
2002 04 11 19 08A013
2002 04 12 19 16A13
2002 04 14 19 45A013
2002 04 14 21 21A13
2002 04 15 21 16A013
2002 04 15 23 00A13
2002 04 16 19 42A013
2002 04 16 21 29A13
2002 04 19 18 20A013
2002 04 19 20 04A13
2002 04 20 21 48A013
2002 04 21 13 31A13
2002 04 24 15 32A013
2002 04 24 20 34A13
2002 04 25 15 47A013
2002 04 25 19 041
2002 04 25 19 06A013
2002 04 25 20 41A13
2002 04 26 15 47A013
2002 04 29 16 04A13
2002 05 01 16 17A013
2002 05 11 00 00A013 **
2002 05 12 10 35A13
2002 05 13 05 42A013
2002 05 13 07 19A13
2002 05 13 10 44A013
2002 05 14 12 31A13
2002 05 15 02 29A013
2002 05 15 10 55A13
2002 05 16 04 15A013
2002 05 16 05 59A13 ***
2002 05 17 04 18A013
2002 05 18 01 06A13
2002 05 19 09 38A013
2002 05 20 08 06A13
200205202104A013
200205202310A13
200205210818A013
200205212314A13
2002 05 22 08 12A013
2002 05 23 06 43A13
2002 06 8 20 29A013
2002 07 05 01 11A13
2002 07 12 01 50A013
2002 07 16 19 37A13
2002 07 19 00 47A013
2002 07 19 21 29A13
2002 07 25 23 34A013
2002 07 26 21 59A13
2002 07 27 23 45A013
2002 07 28 18 50A13
2002 07 31 00 01A013
2002 07 31 15 44A13
2002 08 02 00 13A013
2002 08 02 19 13A13
2002 08 03 00 20A013
2002 08 04 14 22A13
2002 08 06 16 140A13
2002 08 15 08 48A13
2002 08 17 10 24A013
2002 08 18 08 51A13
2002 08 19 15 43A013
2002 08 20 09 00A13
2002 08 20 12 27A013
2002 08 20 15 46A13
2002 08 24 07 38A013
2002 08 24 09 19A13
2002 08 25 09 24A013
2002 08 25 12 49A13
2002 08 26 07 50A013
2002 08 26 12 54A13
2002 08 28 11 25A013
2002 08 29 03 03A13
2002 09 02 10 57A013
2002 09 04 08 36A13
2002 09 06 08 47A013
2002 09 07 00 23A13
2002 09 09 05 39A013
2002 09 15 04 26A13
2002 09 17 01 11A013
2002 09 17 18 32A13
2002 09 18 20 15A013
2002 09 19 17 01A13
2002 09 20 18 44A013
2002 09 21 01 31A13
2002 09 23 17 21A013
2002 09 24 00 04A13
2002 09 24 19 05A013
2002 09 25 00 09A13
2002 09 25 15 47A013
2002 09 25 22 34A13
2002 09 29 17 46A013
2002 09 29 21 08A13*
2002 10 01 12 50A013
2002 10 01 17 58A13
2002 10 03 13 02A013
2002 10 03 18 09A13
2002 10 05 13 24A013
2002 10 05 18 18A13
2002 10 07 11 41A013
2002 10 07 18 26A13
2002 10 09 15 14A013
2002 10 15 08 49A13
2002 10 17 08 58A013
2002 10 17 14 03A13
2002 10 22 11 01A013
2002 10 23 04 17A13
2002 10 23 07 43A013
2002 10 24 02 42A13
2002 10 24 06 03A013
2002 10 24 09 27A13
2002 10 25 01 08A013
2002 10 30 08 14A13
2002 10 31 22 20A013
2002 10 31 22 28A13
2002 11 01 22 15A013
2002 11 03 22 20A13*
2002 11 07 03 39A013
2002 11 08 12 23A13
2002 11 09 02 07A013*
2002 11 11 00 33A013
2002 11 11 19 30A13
2002 11 15 18 06A013
2002 12 20 06 45A13
2002 12 20 08 25A013
2003 06 10 02 00A13
2003 06 14 22 43A013
2003 10 26 08 34A13
2003 10 27 07 10A013
2003 10 30 02 05A13
2003 11 06 21 07A013
2004 08 14 17 47A13
2004 08 18 17 51A013
* At transitions with this mark, the thin shutter is either pulled out or left out, but the operating mode is changed so that once it moves in by its natural criterion, it will not move back out until commanded. Once we determine the time the shutter actually moved in, we will replace this with a standard "A13" transition and change the recorded time to match the time the thin shutter actually moved.

** At this time the deadtime thresholds for entering states (1,3) were lowered from (15%,25%) to (8%,10%) to reduce pileup effects.

*** At this time the thin shutter was already in place due to an earlier flare so changing state had no immediate effect.

This page is maintained by David Smith, who can be reached at dsmith (at) ssl.berkeley.edu