Subject: JEMX Monday Meeting 2005-10-31

2005-10-31

Present: NL, CAO, JC, SB, NJW

JEMX status (SB): Hot spot is still there. During Crab calibration
(revol 365) increases JMX1 temperature by about 5 degC, somewhat
more during OMC flatfielding for HV exercises in revol 370 where
INTEGRAL points closer to the Sun. We should try to correlate the
temperature with the Sun aspect angle.

The technical HV exercise happend in revolution 370 during OMC
flatfielding using the TEST format. JMX1 Fe sources (FRSS)
countrate curves show the efficiency as function of linear PHA value.
The Cd sources did not come quite to PHA values lower than 90
and the more important changes happen in the region 60 - 90.
It was discussed whether the efficiency increases to a higher
value for high PHA values. The electronic part of the energy
resolution behaves more or less as expected. The position resolution
can also be tested with these data by assuming a geometrical
width of the FRSS collimation. The resolution in the Y-direction
(backplane) is worse than in the X-direction (cathode). This
result is expected since the signals from the backplane are
lower than the cathode signals.

Should we ask for new technical observations with more HV steps?
Yes, and we must ensure to get sufficient data for each HV step,
a particular consideration for JMX2.

Side remark (SB, NJW): The attempts to apply neural network
analysis to the source position data have shown (NB, early
undigested result) that including the Sun Aspect angle as a
parameter for the fitting does not improve the result significantly.

Gain calibration (CAO): Revolution 365 for JMX1 (Crab calibration
with HV stepped down for 10 ks) is fitted OK with j_cor_gain-6.4
(j_calib_gain_fitting-7.1). The exercise in revolution 370 has
been removed from the science data so the gain table is empty for
this period.
In revolution 345 there are many and strong glitches so the gain
fit falls considerably below the level where the visual inspection
would place it. Was this during hard space weather? Many glitches
in the calibration sources probably signal increased glitch level
all over the detector.

Science (SB, NL, JC): SAX transient - ATEL is out.
Source confusion around 1744-300/1744-299.

/NJW

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Niels J. Westergaard
Danish National Space Center
Juliane Maries Vej 30, DK 2100 Copenhagen O
Phone: +45 35325705; FAX:  +45 35362475