Gain Notes for Revolution 1459

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 contains one extra inactive period after which there is a 
settling period, just as for the beginning of the revolution. As with the usual
start-of-revolution settling, SCWs from this period of settling should not be used
for energy-sensitive applications, like spectra. OSA 10.0 and later versions, will
automatically discard data within a few SCWs of any kind of instrumental switch on.
Experts can overrule this OSA behaviour, but it should only be done by people who
understand the limitations of the data. During settling the different parts
of the microstrip plates regain their usual surface and volume charge distributions
somewhat irratically, so that the calibration spectra do not reflect the
behaviour on the rest of the plate, and this introduces considerable uncertainty
into the energy calibration process.

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 2-3% of the ideal, except for 5 outlying points, most of which fall
in the settling period of the second switch on. 
As usual, it is also 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 15/10/2014

JEM-X2: 

The Xe line analysis performed using the IC table shows good gain
correction with all science windows (taken 1 at a time) having a Xe level 
within 2-3% of the ideal, except for those immediately after the two switch ons. 
As usual, it is recommended that users avoid the first few science 
windows for energy-sensitive applications (automatically removed by OSA 10.0) and
also those SCWs immediately after the second switch on. THese are also automatically
ignored by OSA 10.0 and later version of the software.


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

CAO 15/10/2014