Gain Notes for Revolution 1056

During this revolution there was a large solar flare that forced all the
instruments into SAFE mode and hence halted data-taking. It also affected
the gain of the two instruments very strongly immediately prior to switch off.
Also, there as a long settling period for both instruments after they were
switched on again. All of this means that the gain varied very strongly in ways
not directly related to the temperature of the instruments. While the IC tables
used to correct the data give very acceptable gain correction for most of this
revolution, other numbers coming out of the science data, like fluxes, may not
be correctly determined. USE DATA FROM THIS REVOLUTION WITH CAUTION.

Note the rapid drop in gain at the start of the flare activity.

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-X2: 

The Xe line analysis performed using the IC table shows excellent gain
correction with all except a few science windows immediately before shutdown
 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.
It is recommended however, that user treat all of this data with caution.


CAO 06/07/2011

	
JEM-X1: 

The Xe line analysis performed using the IC table shows acceptable gain
correction within the large scatter seen on the data, though still 
within about 3% of the ideal, except for obvious misfitted outliers. 
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 20/07/2011