Gain Notes for Revolution 830
	
JEM-X1: This revolution has high detector gain at the end of the revolution
which means that temperature-dependent non-linearities in the energy
calibration appear. These can only be corrected by using an IC gain history
table.

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. 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.

The Xe line analysis of data processed using the new IC table shows that the
energy determination is very stable and to within 2-3% of the ideal. Without
the IC table energy determination is consistently low, in places by as much
as 4%.

However, as for all revolutions, the first few science windows should be
avoided in any analysis requiring very good gain determination. Results shown
here use OSA8.0 software and so include temperature variation in the
smoothed gain model. 

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: No scientific data or gain history data for this unit.

CAO 6/10/2009