Gain Notes for Revolution 1273

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 started with a solar flare that strongly depressed the gain
of both instruments. This affects not only the gain and energy correction but also
the fluxes since many events will now have been rejected by the onboard low end
rejection designed to cut out particles and instrumental noise. The BTI covering
this event is from IJD 4824.1 to 4824.7.
 

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 one other point,
 having a Xe level well
within 3% of the ideal. As usual however, it is recommended that users
avoid the first few science windows for energy-sensitive applications and the
period of the BTI unlees the are experienced users performing energy and
flux insensitive analyses.


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 very good gain
correction with all science windows after the BTI having a Xe level 
within about 3% of the ideal. As usual however, it is recommended that users
avoid the first few science windows and the entire BTI
for energy-sensitive and flux-sensitive applications.

CAO 20/3/2013