Gain Notes for Revolution 1457

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 is another revolution with a short period of switch off, after which there
is a distinct settling period (gain rises significantly, but at different rates all over
the microstrip plate). During these settling periods (i.e. the first few SCWs after 
switch on), the data should not be used for energy-sensitive purposes like spectra. 
OSA 10.0 will automatically ignore data from these periods.
 

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: 

The Xe line analysis performed using the IC table shows very good gain
correction with all science windows (taken 1 at a time) having a Xe level 
within about 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 29/9/2014


JEM-X2: 

The Xe line analysis performed using the IC table shows very good gain
correction with all science windows (taken 1 at a time) having a Xe level 
well within 2% of the ideal, except for 4 SCWs during the two settling periods.
So users should avoid the first few SCWs after both switch ons, 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 15/10/2014