Gain Notes for Revolution 1368

This is one of the later revolutions in the mission where the calibration
sources have become so weak that for the best energy determination and
IC Gain History table is needed.
 
This revolution showed a sudden drop in gain towards the end of the revolution,
apparently due to increase countrate, which produced a non-linear change in
gain which could only be corrected using the IC tables. The processing with IC
tables removes this non-linearity almost entirely.


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 else. 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.

	
JEM-X1: 

The Xe line analysis performed using the IC table shows excellent gain
correction with all, except some obviously misfitted science windows, having a Xe level 
well within 2% of the ideal. As usual however, it is recommended that users
avoid the first few science windows for energy-sensitive applications.


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.


CAO 2/01/2014
	

JEM-X2: 

The Xe line analysis performed using the IC table shows excellent gain
correction with all science windows,  except the very first and some weak
misfitted SCWs,  having a Xe level 
within about 2% of the ideal. As usual however, it is recommended that users
avoid the first few science windows for energy-sensitive applications.

CAO 3/01/2014