Tohban Report 2016-08-24

Tohban Reports
Start Date:	17 August 2016
End Date:	24 August 2016
Tohban:	Juan C. Martinez Oliveros
Tohban email:	oliveros@ssl.berkeley.edu
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Solar Activity

Solar activity during the week was very low. Currently there are three active regions on disk. Solar activity is expected to continue at very low levels with a chance for C-class flares all three days (24-26 Aug) based on recent region trends and lack of activity (continuity).

How many GOES flares occurred?

 Flares above B, C, M, X class were     17     2     0     0

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

 Flares above B, C, M, X class were      4     2     0     0

And how many had EXCELLENT coverage?

 Flares above B, C, M, X class were      4     1     0     0

There were RHESSI flares/GOES flares 11 / 19 over the time range 13-Aug-16 24-Aug-16

Memory Management

The SSR has been emptying at the end of the daily pass set.

Spacecraft Status

Detectors 3 and 8 are active and taking data. The cold tip 1 and 2 temperatures are 115.7 and 114.0.

Currently the Cryocooler power is ~81.5 W.

Data Gaps

No data gaps this week

Detector issues

Detector 8 rear fast threshold was increased by 8 steps to increase its livetime on .

16-231-01:19:51 start idib_chg_thrshld(8, REAR, FAST, 0x70)
16-231-01:19:55 /IDPUDUMPTABL TABLE=DIBTBL8
16-231-01:19:55 /IDPUTABLE8 OFFSET=REARFASTDAC
16-231-01:19:58 /IDPULOAD VALUE=0x70

Spacecraft Management

This week was dominated by a series of cryocooler experiments. First on August 16 the cryocooler power was decreased by 5 W to ~71.5 W, in an effort to determine if the steady temperature increase reported in the previous week was due tapping. After decreasing the cryocooler power a steady increase in temperature suggested to the team that tapping was unlikely and therefore the cryocooler power was increase to its previous configuration of ~76.6 W on the same day. The commanding for that day was the following:

16-229-20:45:26 CP1: 140.4 K 
16-229-20:45:26 CP2: 139.0 K
16-229-20:45:26 CT1: 117.0 K
16-229-20:45:26 CT2: 115.2 K
16-229-20:45:26 TST: 183.1 K
16-229-20:45:26 cp1 - ct1 = 23.19 K
16-229-20:45:26 Cryo Power: 74.2 W
16-229-20:45:26 Cryo Accel: 10.6 mG

16-229-20:44:42 /icryomain power=142
16-229-20:44:53 /icryobal amplitude=194
16-229-20:45:29 /icryomain power=140
16-229-20:45:34 /icryobal amplitude=192
16-229-20:45:50 /icryomain power=139
16-229-20:45:53 /icryobal amplitude=191

16-229-21:02:20 CP1: 140.4 K
16-229-21:02:20 CP2: 139.0 K
16-229-21:02:20 CT1: 117.8 K
16-229-21:02:20 CT2: 115.9 K
16-229-21:02:20 TST: 182.8 K
16-229-21:02:20 cp1 - ct1 = 22.63 K
16-229-21:02:20 Cryo Power: 71.4 W
16-229-21:02:20 Cryo Accel: 10.1 mG

16-229-22:23:39 /icryomain power=140
16-229-22:23:51 /icryobal amplitude=192
16-229-22:24:06 /icryomain power=142
16-229-22:24:12 /icryobal amplitude=194
16-229-22:24:16 start write_ssr_info
16-229-22:24:33 /icryomain power=144
16-229-22:24:40 /icryobal amplitude=196

After discussion a second test was devised, increasing the cryocooler power by 5W to ~81W, in an effort to determine the likely tapping temperature and decrease the rate at which the system is warming up. Because this operation required the team to violate the cryocooler power curve and possible disruptions in the loading of ATS tables were a possibility, it was decided to make the experiment in the following steps:

- First a new ATS table will be generated with an automatic commanding to decrease the cryocooler power by 1 W and the increase the power by 1W to the original value after one minute. This experiment was successful and demonstrated that it can be possible to automatically operate the cryocooler power.

- A new ATS table will be loaded the next day with an automatic commands to decrease the cryocooler power by 5 W after two orbits. This procedure was made in case the noise generated by the cryocooler made impossible to load long ATS tables and also commanding. In case that commanding and ATS loads were possible, was decided to reconvene the next day to decide if we should continue at this temperature for a day, adding the same kind of failsafe. During the experiment was demonstrated that ATS tables could be load at a higher cryocooler power without any problem and therefore also individual commands. After, discussing the results of the test it was decided to leave the cryocooler at the current power of 81W, as it showed a temperature decrease in the cold tips and cold plates of about 0.5 degrees.

The next are the commands for both days

16-230-00:02:59 CP1: 140.5 K
16-230-00:02:59 CP2: 139.0 K
16-230-00:02:59 CT1: 117.1 K
16-230-00:02:59 CT2: 115.2 K
16-230-00:02:59 TST: 182.8 K
16-230-00:02:59 cp1 - ct1 = 23.26 K
16-230-00:02:59 Cryo Power: 76.6 W
16-230-00:02:59 Cryo Accel: 11.6 mG

Before Test Power Increase

16-231-16:47:53 CP1: 140.7 K  
16-231-16:47:53 CP2: 139.2 K  
16-231-16:47:53 CT1: 116.9 K  
16-231-16:47:53 CT2: 114.9 K  
16-231-16:47:53 TST: 182.8 K  
16-231-16:47:53 cp1 - ct1 = 23.80 K
16-231-16:47:53 Cryo Power: 75.9 W
16-231-16:47:53 Cryo Accel: 11.2 mG

Power Increase Pass

16-231-19:50:53 start sc_ats_control  ; switch to ATS with safety ramp down commands 

Raise cryocooler power to 81 W

16-231-19:51:20 /icryomain power=146
16-231-19:51:33 /icryobal amplitude=198
16-231-19:51:59 /icryomain power=148
16-231-19:52:06 /icryobal amplitude=200
16-231-19:52:43 /icryomain power=149
16-231-19:52:48 /icryobal amplitude=201

Load additional ATS just to see if it is possible, at this power level

16-231-19:54:01 start sc_ats_load(T16231SLTN33.01)

Load succeeded without any dropped commands

On Orbit After Increasing to 81 W

16-231-21:29:08 start sc_ats_control ; Switch to ATS with safety commands at 232-19:34 UTC
16-231-21:36:14 CP1: 140.7 K  
16-231-21:36:14 CP2: 139.1 K  
16-231-21:36:14 CT1: 116.4 K  
16-231-21:36:14 CT2: 114.6 K  
16-231-21:36:14 TST: 182.5 K  
16-231-21:36:14 cp1 - ct1 = 24.33 K
16-231-21:36:14 Cryo Power: 80.9 W
16-231-21:36:14 Cryo Accel: 13.0 mG

Decimation	Normal/Vigorous
HLAT Decimation	No Rear decimation, no front decimation
Night time data (fronts)	full-time
Night time data (rears)	full-time
Require extra passes?	No
Requirement for moving pointer?	No
Attenuator operation	Working as expected
Detector problems?	See notes above.