Gain Notes for Revolution 858
	
JEM-X1: 

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.

Without using the IC table, the energy calibration is consistently about 4%
too low, which is not a catastrophe for non-spectral applications like
imaging, lightcurves and position determination, but data corrected only 
with the automatic gain history table should not be used for spectral
analyses of the data.


Calibration source number 4 (purple/orange) is no longer
used for calibration purposes since an anode strip directly under the source
has broken and no useable signal comes from this area of the detector any
longer.


JEM-X2: A quite normal revolution with fine gain fitting. All the data from 
this revolution should be useable. The Xe line analysis confirms the very
excellent gain calibration for this revolution with all except the very first Science
Windows having a Xe line position with about 1% of the ideal value.
As always, however, it is suggested that
users avoid the first few science windows in each revolution since this is
where the instrument warms up and gain variations across the plate settle down.



CAO 30/11/2009

JEM-X1 IC gain history table created, verified and delivered
Using IC table, average Xe position is perfect and for all SCWs Xe line lies
within 3% of the ideal.
CAO 2/12/2009