Subject: JEMX Monday meeting 2004-08-30

Present: ILR, SB, CBJ, JC, NL, CAO, NJW

JEMX status: DFEE of JMX2 has been off in 2 revolutions. Inside the JMX1
             detectorbox the temperature drop has been 5 deg. Also seen
             in the connector J0 thermistor. The gain behaves approx. as
             predicted i.e. a decrease of 5%. From FRSS#1 the energy
             resolution is not affected.
             Conclusion: We can continue with DFEE2 off. No objections
             from IBIS. The deceleration of the ageing cannot be confirmed
             until after a couple of months.
             
             The limit of 25000 cts/8s in software triggers has caused
             a stop in data acquisition during Sco x-1 observation in rev
             229. For the upcoming observations of this source this limit
             should be changed to a higer value. ISOC should take care of
             this and warn us when a new Sco X-1 observation is planned.
             
Grey filter and deadtime: CBJ has applied the formula used by NL in his
             software for calculating the livetime of the instrument. He
             could not avoid abrupt changes in the corrected countrate
             from Sco X-1 unless the formula was adjusted.
             NL and CBJ will continue this investigation.
             It has no effect on the ISSW since the derivation is done in
             a different way.
             
Raw pixel redistribution: NJW has derived a pixel redistribution table based
             on CBJ's Ferrara pixel corner determination. The translated
             pixel corners give correct positions for the collimator shadows
             (Crab 2 deg off axis). However, the correlation between number
             of counts in the individual pixels and the pixel size is worse
             than statistical fluctuations. But basically the pixel redistri-
             bution works; a special version has been tested with midisky.
             
Midisky/JEMIROS: NL is still working to get closer to ISDC standards.

ISDC activities: JC will go to ISDC Sunday evening (5/9 2004). A recuperation
             of IS data from the drop out in revolution 225 is planned.
             
AOB:         GRB 040812 Chandra points to source a bit too far away from
             our position. Hopefully a new Chandra observation is on the way.
             SN1006 just visible in mosaic images from midisky.
             Some bursts seen, GRS1915 very active again.


/NJ
           
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Niels J. Westergaard
Danish Space Research Institute
Juliane Maries Vej 30, DK 2100 Copenhagen O
Phone: +45 35 32 57 05; FAX:  +45 35 36 24 75