Gain Notes for Revolution 949
	
JEM-X1: No scientific data or gain history for this unit.


JEM-X2: Unfortunately, due to high gain (about 25 channels/keV) and aging
of the instrument, this revolution has poor gain correction, giving a
Xe level around 29.0 keV rather than 29.6 keV. For the best gain correction
an IC gain history table is required as described below.


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. The updated ISDC Instrument Characteristics
can be downloaded from
http://www.isdc.unige.ch/integral/download/osa_sw


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 performed using the IC table shows excellent gain
correction with all except the very first science windows having a Xe level 
within 1% of the ideal. As usual however, it is recommended that users
avoid the first few science windows for energy-sensitive applications.

CAO 3/09/2010