Gain Notes for Revolution 1327

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.
 

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 good gain
correction with all science windows that have a realistic fitted width having a Xe level 
within 2% of the ideal. Hoever, a very large many of the SCWs to not have a precise
determination of the Xe line position themselves because the detector background
lines are swamped by strong galactic sources whenever the dithering pattern brings these
in the centre of the FOV. So long as the well-determined Xe lines stay in the right place,
as here, this does not indicate any deterioration of the energy calibration.
As usual, 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 good gain
correction with all science windows with a good fit having a Xe level 
within about 2% of the ideal. However, as with unit1, there are many misfitted
SCWs with unrealistically large or small fits, where the Xe line is simply swamped
by the strong sources as the dithering pattern brings them into full view.
As usual, it is recommended that users
avoid the first few science windows for energy-sensitive applications.

CAO 29/08/2013