Gain Notes for Revolution 2803

The end of this revolution is affected by solar activity, during which
	the Xe line cannot be seen and the gain determination cannot be verified.
	During this Bad Time Interval is is not recommended to perform science
	analysese that are energy critical (i.e. make spectra or energy-binned light curves).
	However, this data is still good for imaging and location of new sources. 
		 BTI = 8970.0 to 8971.0 IJD.

This is one of the later revolutions in the mission where the calibration
sources have become so weak that for the best energy determination an
IC Gain History table is needed. These gain history tables are found
automatically by OSA, or can be downloaded from the DTU FTP site.

 
All offline gain/energy corrections (including the IC tables) are based on the
two Fe calibration sources in JEM-X1, for both units, then corrected iteratively
using the instrument background lines (Xe, backed up by Cu and Mo).

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:  Excellent prior to the onset of solar activity (Xe line positions 
	within about 2% of ideal, except for settling zone). During BTI correctness of
	gain determination cannot be determined. 

JEM-X2 rating:  Very excellent prior to BTI (within 1--2\%\ 
	of ideal, except for settling zone). Very low position of the Mo line may be 
	indicative of gain suppression on the microstrip plate during the BTI.

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 29/07/2024