Gain Notes for Revolution 2380

NB: There were technical difficulties during the first half of this revolution
so that about 0.8 days of data are missing. Also, Cyg X-1 was in the FOV, and
this meant a lot of grey filtering that cut out calibration data as well as
science events, and led to poorer gain determination. However, this was not
a serious problem.

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. This gain history table was created using
consolidated data, which means the consolidated data energy correction was
done without the offline gain history table, and hence is incorrect.
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ALWAYS START YOUR PROCESSING AT COR LEVEL WHICH WILL AUTOMATICALLY USE THE
OFFLINE GAIN HISTORY TABLE FOR ENERGY DETERMINATION - DO NOT USED THE ARCHIVED
CONSOLIDATED DATA ENERGY VALUES.
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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 rating: Very Good (Xe line positions within 3% of ideal, except for
	misfitted lines caused by weak calibration spectra and instrumental
	lines).

CAO 30/07/2021

JEM-X2 rating:  Also very good, within 2-3% of ideal. Settling zone and multiple
	misfits are however, outside this range, and compromised by strong
	grey filtering.

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

CAO 04/08/2021