Gain Notes for Revolution 1590

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 2 at a time) having a Xe level 
within 2-3% of the ideal, except for some noisy, greyfiltered revolutions
at the end for which Xe position cannot be individually determined. These
noisy revolutions have energy determination uncertainty of 5-10% or more,
but the weakness of the calibration signal makes it very hard to be sure.
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 2 SCWs at a time) having a Xe level 
within 21-% of the ideal, except for very weak Xe lines seen in the last few
SCWs for which no Xe line can be fitted. The energy uncertainty on these
SCWs may be  10% or more so caution should be used when using these data
for energy-sensitive applications. 
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 7/10/2015