Subject: JEM-X Monday Meeting 2006-12-04
Date: Fri, 22 Dec 2006 11:07:26 +0100 (MET)

Present: SB, JC, NL, NJW.

JEM-X status (SB): Some hotspot activity in revolution 504.
RAWXY = (72,16). Peaking at low energy as usual. Very irregular
'lightcurve'.
Power failure at ISDC so instrument station wasn't running properly
this morning, but it has been stated up now by the operations people
at ISDC.
Background correlation with Oulu neutron monitor data: Since launch
we have seen an increase of 80% in the hardware trigger rate.
Also a good correlation between JEM-X hardware trigger rate and IREM
3 rate.
This increase of the particle flux has no effect on our intrinsic
background of accepted events, which must therefore be due to cosmic
gamma radiation. The lost anodes has also a dimishing effect on the
accepted event rate. 
The orbit is changing - the altitude of the perigee is decreasing
at the moment and an analysis to study how an orbit change should
be done. We will look at the radiation intensity along the orbit
with the current orbit parameters.

Shadowgram distortions (NL): The limits between the anode sections
seem to have an effect on the position accuracy of the events.
Updating the position correction with this result did not improve
the fit quality, however. There can be a software bug, not yet located,
but a thorough search is ongoing.

/NJW