RHESSI Tohban report, 28-oct-2002 to 4-nov-2002 H. Hudson, hhudson@ssl.berkeley.edu 1. Solar Activity: One X1.3 flare, well-observed by RHESSI. The tohban has no comments about gamma-rays from this one, but notes that it was very impulsive and of short duration. The duration was so brief, in fact, that the "true" GOES class of X1.3 was averaged down to about M8 in the 1-minute sampling. Independent research shows that it was X1.4 in the 3-sec data. The OVRO 1 GHz flux lined up quite well with the RHESSI spike, confirming this tohban's view that type III - like centimetric emission commonly matches the timing of the impulsive phase, which could be interpreted to mean high densities on open field lines. See http://sprg.ssl.berkeley.edu/~hhudson/tohban_science for OVRO, RHESSI, and GOES timing plots. It is hard to find centimeter-wave data for comparisons. 2. Coordinated obervations: None that we knew about. 3. Memory Managment (excerpt from ~tohban/public_html/logs/shutter.log): A013-> A13 30-oct-2002 08:14 A13 -> A013 30-oct-2002 22:20 A013-> A13 30-oct-2002 22:28 A13 -> A013 31-oct-2002 22:15 4. Intentional Data Gaps: Not really a gap, but now entered in the tohban gaps log to alert people: there was a RHESSI spin-up operation November 2 UT, which will have resulted in screwy SAS data. 5. SSR management The tohban eavesdropped on e-mail exchanges among Brian, Mark, Manfred, and David, concerning how to manage the SSR better. Brian's idea seems to be to move the front-segment decimation threshold downwards from its present level of 50%. The tohban therefore examined some of the archived data to see what difference this would make. Are decimated shutter-open data of any value? The answer is a resounding "yes". We can still see microflares quite well, although the 10 keV Ge feature seems more prominent relative to them. A good example is on 2 July, about 16:00. There are transitions also visible at 14 October 19:10 and 14 October 22:30. It was actually fairly hard to find a sample to look at, just going from the Web archives without trying to program the quicklook log data. The tohban thinks that this means that decimation of the front segments is rather effective. The bottom line, as I think proposed by Brian, is that moving the onset of front-segment decimation down to 30% might let us keep A013 going almost all the time, at some cost in SNR on microflare images and spectra. But we already have quite a large database. 6. Problems The status page was detected again showing blank counts on its last overwrite following the first GBS pass on 3 October. This was a nuisance because a flare was in progress and the MOC was locked. Then, on the third pass, the status page locked completely (not, according to Mark, related to the dreaded "blue screen death"). This system ought to be solid now that there may not be an operator physically present in the MOC. The decimation rules have not been easily accessible. Now there is an e-mail from David Smith with the gory details, which I have linked on the tohban home page http://sprg.ssl.berkeley.edu/~tohban/ for all to ponder. 7. Tohbans Week of 5-Nov to 11-Nov: Amir Caspi, with RHESSI trainee (but veteran tohban) Satoshi Masuda. Week of 12-Nov to 18-Nov: Satoshi Masuda