RHESSI Tohban report, 15-June-2004 to 21-June-2004

1. Crab offpointing

The Crab observations occupied all week, and no updates to the
pointing were made. We are eager to see the status on Monday
and will need to decide when to end the experiment. It appears
that it would be a waste of time to experiment with shutter
calibration exercises, since there is really not enough SNR.

2. Solar Activity

Activity was not negligible, so there will have been some hit
on Crab SNR at the lowest energies (<10 keV). It was not high
enough to suggest going back to the Sun early, though.

HSI_TOHBAN_FLARE_COUNTER shows the following statistics:

How many GOES flares occurred?
  Flares above B, C, M, X class were     33    16     1     0
And how many of these are listed in the RHESSI flare list?
  Flares above B, C, M, X class were      4     7     1     0
And how many had EXCELLENT coverage?
  Flares above B, C, M, X class were      3     6     0     0
       
There were RHESSI flares/GOES flares          28 /           50
over the time range 13-Jun-04 20-Jun-04


2.5 Flare Catalog

This has been a week of pure offpointing to the Crab, and we can
see a couple of effects. First, the fraction of GOES events
appearing in the RHESSI flare catalog is much-diminished, consistent
with the reduced sensitivity from the offpointing. Second, the
RHESSI/GOES catalog ratio of 28/50 probably indicates something
about the rate of accidentals (mainly particle events confused
with flares) in the RHESSI catalog.

Interesting cases for Jim: 

13-Jun 12:20 and 12:26 (both artifacts, but why two?)
13-Jun 13:56 and 14:03 (in FLIST but not flagged on the QL plots)
13-Jun 20:40 (3 triggers)

3. Memory Management

The SSR content drifted up during the week until 30% was exceeded,
producing some unwanted decimation. The probable cause of the memory
use was a cyclic upturn in particle counts. The special Crab decimation
table (#16) created by David was initiated today (21-Jul 19:10:43).

4. Data Gaps

No significant data gaps.

5. Next tohban: Paula Balciunaite 

Respectfully submitted

Hugh Hudson
hhudson@ssl.berkeley.edu