Gain Notes for Revolution 1724

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.
 

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.

All offline gain/energy corrections (including the IC tables) are based on the
two Fe calibration sources in JEM-X1, for both units.

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 SCW at a time) having a Xe level 
within 2-3% of the ideal, except for for the usual settling points at the
start of the revolution. Most points are well within 2% of ideal and the scatter
is significantly larger than revolutions that would be deemed 'excellent' . 
As usual, it is recommended that users avoid the first few science 
windows for energy-sensitive applications (automatically removed by OSA 10.0).

JEM-X2: 

The Xe line analysis performed using the IC table shows excellent gain
correction with all science windows (taken 1 SCW at a time) having a Xe level 
within 1-2% of the ideal, except for the settling points, and a few
completely misfitted lines, including the very last SCW. Such misfit usually
indicate grey filter activity during which is it not possible to confirm
the calibration because the instrumental lines have too few counts. However,
if all SCWs to either side of misfit are correct it is certain that the
unverfied SCWs also have the same goodness-of-energy-determination characteristics
as the neighbouring SCWs.

As usual, it is recommended that users avoid the first few science 
windows for energy-sensitive applications (automatically removed by OSA 10.0).

The JEM-X2 corrections are based on the JEM-X1 Fe calibration sources, since
all the Cd sources are now to weak to use.

CAO 15/09/2016