Gain Notes for Revolution 2664

The gain data and indeed the background line data is so weak for
		this revolution that it is not possible to perform gain corrections with
		any meaningful accuracy, though this has been tried. Therefore
		this revolution is declared a BTI for uncertain instrument parameters
		between 8599.0 and 8601.2 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:  Poor to indeterminate.

JEM-X2 rating:  Poor to indeterminate.

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 01/08/2023