Gain Notes for Revolution 2491


N.B.: This is a very noisy revolution in which some calibration data has
been reduced by periods of grey filtering which have somewhat compromised
the uncertainty on the energy determination for JEM-X1. 

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 rating: Mostly good (Xe line positions within about 4% of ideal, except for
	some misfits) This is a very noisy revolution, and this is the best that
	can be done. 

JEM-X2 rating: Very good (within 2-3% of ideal) - not noisy like JEM-X1

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 27/04/2022