Gain Notes for Revolution 1075
	



	Gain Notes for Revolution 1075

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.A solar flare in this revolution forced the instruments
into SAFE mode, though the effect of the flare (decreased gain due to plate charging)
is already apparent in the last 5 or so science windows before the shutdown. 
It is recommended that users avoid the science windows just before the shutdown.
 

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 most SCWs,  except the misfitted, weak ones, 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 excellent gain
correction with all except the very last science windows having a Xe level 
within 1-2% of the ideal. As usual however, it is recommended that users
avoid the first few science windows for energy-sensitive applications.
For this revolution, in which a solar flare forced an autonomous shutdown
of the instruments, the last 4 or so science windows before the shutdown are
also of dubious quality and very poor gain determination, and it is recommended
that users do not use these science windows.

CAO 9/8/2011