Gain Notes for Revolution 2189

NB: This revolution has some odd behaviour in the settling period (first 8 SCWs)
which is usually cut out automatically by the OSA software. However, for users
interested in SCWs during the settling period, energy values may have to be
corrected individually for this strange behaviour that cannot be corrected
on a SCW-by-SCW basis by this offline analysis. Check that the strong
instrumental Xe line in your science data is at 29.6 keV. If the line is more 
that 5% off this value, all energy values should be corrected by a factor of
29.6/<Xe position>.


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: Very good (Xe line positions within 2-3% of ideal, except for settling zone)

JEM-X2 rating: Exemplary outside settling zone (within about 1% of ideal) but SCWs in
	the settling zone need to be adjusted by users on a SCW-by-SCW basis.

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 11/02/2020