Gain Notes for Revolution 1452

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: This revolution was affected by some very poorly understood gain suppression
problems, which it has not been possible to correct. Therefore there has been declared
a Bad_Response BTI, which means that for energy-sensitive applications this time period
will be ignored by the ISDC OSA software. Experienced users can override this BTI by
using a  user-defined GTI, but should be aware that this will give poor results for 
spectra and other energy-dependent data. BTI = 5360.40 to 5362.6 IJD
 

To get optimal results with this revolution it is necessary to use the IC gain history.
See notes in revolutions prior to revolution 1433 to find out how to do this
if you don't already know.

Latest OSA software (version 10 and higher) automatically cuts out the first
Science windows of data from each revolution to ensure that people do not use data
from the instrument-settling period. This process can be overruled, but only by
experienced users.
	
JEM-X1: 

NB: This revolution was affected by some very poorly understood gain suppression
problems, which it has not been possible to correct. Therefore there has been declared
a Bad_Response BTI, which means that for energy-sensitive applications this time period
will be ignored by the ISDC OSA software. Experienced users can override this BTI by
using a  user-defined GTI, but should be aware that this will give poor results for 
spectra and other energy-dependent data. BTI = 5360.40 to 5362.6 IJD
 

The Xe line analysis performed using the IC table shows excellent gain
correction with all science windows (taken 2 at a time) outside fo the BTI,
having a Xe level within 2% of the ideal, except for the very first SCWs. 
As usual, it is recommended that users avoid the first few science 
windows for energy-sensitive applications (automatically removed by OSA 10.0).


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 22/9/2014

JEM-X2: 

The Xe line analysis performed using the IC table shows very good gain
correction with all science windows (taken 2 at a time) having a Xe level 
within 2% of the ideal, except for 4 points, and the very first SCWs. The
outlying 3 points are within 3% of ideal and only the very first SCWs are
completely off the scale.
As usual, it is recommended that users avoid the first few science 
windows for energy-sensitive applications (automatically removed by OSA 10.0).


As with JEM-X1, source 4 is no longer used for energy correction purposes due
to a broken anode strip

CAO 29/9/2014