Gain Notes for Revolution 1025

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 was unusual in that the gain on the microstrip plate did not follow
the highly variable, high temperatures measured on the electronics box. To overcome
this problem the IC table is broken up into artificial time zones so that each part of
the revolution can find its own relationship to the measured temperatures. Unfortunately,
the Xe line was still so weak that even with two SCWs added together for each Xe line
analysis there is a part of the revolution  where it simply isn't possible to fit the
Xe line correctly, and the line contains alot of scatter.
 

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 acceptable gain
correction with all except the very first science windows and poorly fitted outliers
 having a Xe level 
within 3% 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.



JEM-X2: 

The Xe line analysis performed using the IC table shows good gain
correction with all except the very first science windows having a Xe level 
within 2-3% of the ideal. As usual however, it is recommended that users
avoid the first few science windows for energy-sensitive applications.

CAO 11/04/2011