Tohban Report 2012-11-14
From RHESSI Wiki
|Start Date:||7 Nov 2012|
|End Date:||14 Nov 2012|
|Next Tohban:||Hazel Bain|
|List all reports|
Activity was reasonably high this week. There were a few large regions on the disk producing M class flares. A major flare watch was called for NOAA 1613 which produced 4 M class flares. Activity might continue at these levels if these region maintain their complexity (although the MFW has been cancelled).
How many GOES flares occurred?
Flares above B, C, M, X class were 8 30 7 0
And how many of these are listed in the RHESSI flare list?
Flares above B, C, M, X class were 6 20 5 0
And how many had EXCELLENT coverage?
Flares above B, C, M, X class were 2 8 3 0
There were RHESSI flares/GOES flares 292 / 45 over the time range 07-Nov-12 14-Nov-12
SSR has reached a maximum of 20% and has been emptying at the end of the day. We are in active vigorous mode and might want to consider normal vigorous.
Only 2 x 5 minute gaps.
Optimization of Detector 2 was investigated by lowering the high voltage by 12 steps (four steps at a time). This produced only a small improvement. So we put the voltage back to where it was and increased the front slow threshold further. This had a more significant effect, but still not as much as we hoped for. Also, the front slow threshold is now quite high. I don't have the conversion table for the threshold values, but David can tell us what the 0x88 translates to. We left it with high voltage unchanged and the front slow threshold set to 0x88. The slow rates on G2 have dropped significantly and are now only marginally higher than the other detectors. However, sensitivity at low energies is almost non existent.
David has suggested it may be worth lowering the high voltage a lot (perhaps 40 steps) to see if that eliminates the noise. This might, in turn, allow us to reduce the threshold. David discussed the possible hysteresis effects and problems that long term radiation damage might cause.
We should lower the voltage by ~40 steps when the passes are back during the day. Lower the voltage by 40 steps and then play with threshold in one pass. Radiation damage is not that important since it can't be used for high res imaging.
|Night time data (fronts)||+/- 4 minutes|
|Night time data (rears)||+/- 4 minutes|
|Require extra passes?||No|
|Requirement for moving pointer?||No|
|Detector problems?||Not significant ones. G2 front slow threshold set to 0x88.|