Tohban Report 2015-01-14

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Tohban Reports
Start Date: 7 Jan 2015
End Date: 14 Jan 2015
Tohban: Lindsay Glesener
Tohban email:
Next Tohban: Hazel Bain
List all reports


Solar Activity

Overall, this week was a bit quieter than last. There are 7 active regions on the disk, with one of them (AR 12257, at the west limb) producing many C and M class flares. This is a fairly recent burst of activity that started early Tuesday; before that time solar activity was quiet-to-moderate. There is a Major Flare Watch in place. This AR will rotate off any second, and there isn't a lot else active, so solar activity is expected to drop soon. There should be a day or two of good opportunity for occulted flares.

How many GOES flares occurred?

 Flares above B, C, M, X class were      0    39     2     0

And how many of these are listed in the RHESSI flare list?

 Flares above B, C, M, X class were      0    27     1     0

And how many had EXCELLENT coverage?

 Flares above B, C, M, X class were      0     0     0     0

There were RHESSI flares/GOES flares 294 / 41 over the time range 07-Jan-15 14-Jan-15

Memory Management

The SSR fill slowly crept up over the weekend, and by Tuesday was reaching a max of almost 50%. That coincided with the Major Flare Watch call, so several actions were taken at once to reduce the fill: the decimation state was changed, nighttime events were turned off, and D7 slow threshold was raised to its previous value. After those actions, the SSR fill was brought down to 28% in one pass set, so these actions appear to have been successful in quickly alleviating the memory stress. These actions could now be reversed one by one, although it may be best to wait until the AR is fully rotated off.

Those actions took place on Jan 13 at 19:28 UTC.

For the next tohban: wait a day or so, then assess memory and solar activity and change the decimation and/or nighttime settings. Also take a look at D7 spectra, during flares and otherwise, to see if there are actual useful solar flare data at low energies.

Spacecraft Status

Data Gaps

Data from yesterday (Jan 13) is being listed as a gap but just probably isn't down yet.

An honest-to-goodness gap on the 7th. 2015-01-07T07:00:00.000 -- 2015-01-07T07:55:00.000 3300.0000 sec


We increased the "HV cut off" limit to 145 K on the coldplates. The red and yellow limits on the cold plates themselves have been adjusted accordingly. The yellow limit is now 135 K and red is now 140 K. This commanding was done at 2015-009-19:08:46 UTC.

Brian's long-term temperature trend plots show that an "anomaly" occurred in late December. At this time, accelerations increased and the cryocooler efficiency went down. The efficiency has leveled off, so it looks like the best tactic for now is to wait and see what it does. In two weeks, we'll have a discussion about whether to take more action, i.e. whether to try increasing (or decreasing) the power and look for an effect on accelerations and efficiency. Brian also notes that we should be watchful of the Cold Tip temperature to ensure that we're staying below the "safe" cooling curve.

Tohbans are requested to regularly monitor Cold Plate 1 temperatures to look for fast increases like the one that occurred in December, and also to monitor Cold Tip temperatures to ensure that we stay in the safe zone.

Detector issues

On Jan 8, we changed rear fast thresholds on three detectors because of poor livetime:

 15-008-17:44:15 /IDPULOAD VALUE=0x50           ;(was 0x45)
 15-008-17:45:18 /IDPULOAD VALUE=0x50           ;(was 0x45)
 15-008-17:46:04 /IDPULOAD VALUE=0x50           ;(was 0x45)

On Jan 13 at 19:27 UTC we raised the front slow threshold on D7 due to SSR fill creeping up:

 15-013-19:27:36 /IDPULOAD VALUE=0x10 ; increased from 0x0C

Detectors 1,3,6,7,8, and 9 are stably segmented. Detector 5 is segmented, but still not quite stable, but getting more stable all the time. Detectors 2 and 4 are still unsegmented.

We still see light leak on detectors 2, 5 and 9.

Other notes

Spacecraft Management

Decimation Active/Vigorous
Night time data (fronts) Off
Night time data (rears) Off
Require extra passes? No
Requirement for moving pointer? No
Attenuator operation Normal
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