Gain Notes for Revolution 1113

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: The end of this revolution was strongly affected by solar activity, so that
from IJD 4347.7 onward, the revolution is declared a BTI, and standard OSA
processing will ignore all science data after this time. Though results with
the IC table show fine energy calibration during this period it is certain that
other quanitities like the flux will not be good, and spectra from this BTI
should not be used.
 

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 a couple of science windows having a Xe level 
within 2% of the ideal, and the others within 3%. 
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 excellent gain
correction with all except two science windows having a Xe level 
within 2% of the ideal, the outstanding pair are within 4% of the ideal. 
All science data beyond IJD of 4347.7 will be ignored by OSA processing
since the period beyond this time, and into the first part of
revolution 1114 has been a BTI.
As usual however, it is also recommended that users
avoid the first few science windows in this revolution 
for energy-sensitive applications.

CAO 1/03/2012