Gain Notes for Revolution 1570

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 excellent gain
correction with all science windows having a Xe level 
within 2% of the ideal, except for a handful of completely misfitted
points. These are not indicative of bad gain fitting but only of a lack
of data probably due to greyfiltering during high countrate periods. 
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  extremely excellent gain
correction with all science windows having a Xe level 
within 1% of the ideal, except for the first and last points which stray moderately
outside this boundary. The two short periods of extreme misfitted SCWs demonstrate
that this is due to grey filtering just as with unit 1, which indicates lack of
calibration data rather than bad calibration. Since the SCWs each side of these
periods are extremely well corrected the periods with grey filtering will be
similarly well corrected. 
As usual however, 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 14/8/2015