Gain Notes for Revolution 2459
	


	Gain Notes for Revolution 2459

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: Acceptable. After the settling zone, Xe line position is excellent,
	within about 2% of ideal, but after IJD 8055.2 there is a sudden drop in 
	gain, and a loss of SCWs that make it hard to correct. Each of the science
	windows has a Xe line within about 10% of the correct value. Users who find
	a Xe line in these science windows can correct all the energy values by 
	multiplying by a factor 29.6/(Xe line position in SCW) , if better energy
	determination is needed. 

CAO 28/01/2022

JEM-X2 rating: Excellent (within about 2% of ideal except for first and last points)
	If a Xe line can be found in the fist and last SCW of the revolution, 
	correct all energy values with the formular given above. 


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 26/01/2022