Gain Notes for Revolution 950
	
JEM-X1: No scientific data or gain history for this unit.


JEM-X2: A combination of factors including autonomous switch on and off
due to very high count rates from SCO X-1, 
have deteriorated the quality of the energy calibration
for this revolution. The period IJD=3858.00 to 3858.60 has been declared a
Bad Time Interval and data from this time will not be processed by OSA

To get optimal results with this revolution it is necessary to use the IC gain history
table that has been created offline at DNSC, instead of the gain history table
created automatically by OSA. If you have the newest package of IC files from ISDC
and these are correctly installed, OSA will find the IC gain history table automatically
and you don't need to do anything. However, if you don't have the IC gain table
package from ISDC you can download the table from the gain history archive by
anonymous ftp through the link provided. Download the table to some suitable
subdirectory for your analysis, then set the hidden OSA parameter gainHist:
gainHist="<my subdirectory>/<IC filename>". These files are used instead of the
automatically generated gain history tables wherever there has been an unusual or
non-linear behaviour of the detector gain.


The Xe line analysis of the science data processed with the IC table shows
that good gain calibration has been achieved with an average Xe level
at 29.42 keV with most of the science windows having a level within 2% of
the ideal. However, there is a period between  IJD=3859.20 and
IJD=3859.60 where energy correction is somewhat worse than this. This is
due to the increasing non-linear temperature dependence of the instrumental
gain as the instrument ages.

CAO 1/09/2010