Gain Notes for Revolution 2741

This was a very noisy revolution with high background radiation due to
		solar activity. It contains the start of a BTI during which JEM-X
		was switched off because of the high radiation level. 
All of the next revolution is a BTI too, for which there is no science
		or calibration data.
BTI = IJD 8805.5 to 8808.7

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: Good (within 4% of ideal, except for settling zone,
		some extreme misfits and the SCWs immediately before the shutdown, which are
		covered by the BTI.)

JEM-X2 rating: Also good.
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 14/02/2024