Gain Notes for Revolution 1093

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: This revolution suffered some severe gain perturbation due to solar activity,
to which the instruments have become considerably more sensitive with age.
It was necessary to do the gain smoothing of each gain history table in several
separate discontinuous pieces, which has produced good energy determination for the
vast majority of science windows in this revolution. However, the rapid changes in
gain, which will vary in an uncorrectible manner across the microstrip plate, means
that both the Mo and Cu lines have been wiped out - indicating that energy determination
is not equally good for all parts of the plate, and energy resolution in general has
been degraded.
 

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 with all except the very first science windows and some weak
outliers having a Xe level 
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 30/11/2011



JEM-X2: 

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

CAO 05/12/2011