Gain Notes for Revolution 1281

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.

NB: An M-class flare disrupted this revolution so that part of it is a BTI and
the data should not be used. The BTI covers the time period 4849.2 IJD to 4850.0 IJD.
The ISDC software (OSA) will automatically ignore this data, but experienced users
can force the data to be used by specifying a user GTI. However, even after the flare,
where the gain correction is good again, flux determination can be uncertain due to
very low gain and other issues.
 

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 very good gain
correction outside the BTI, with all science windows, except the first 8, and
some misfitted outliers,  having a Xe level 
within 3% of the ideal. As usual, it is recommended that users
avoid the first few science windows  and last few SCWs 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: Results coming soon.

CAO 13/05/2013