Gain Notes for Revolution 2034

N.B: This revolution contains dithering observations of Cyg X-1 during which
strong gain suppression is seen in the calibration data, that is not carried
over onto the rest of the microstrip plate. Consequently a gain smoothing model
has been chosen that ignores the countrate-dependent variations (model=3)and
this gives excellent/exemplary results. Also grey filtering during the 
on-axis observations completely destroys the Xe background line making it
impossible to judge the quality of the energy determination for one of the SCWs
for JEM-X1 in this revolution. However, since SCWs either side of this one are
well corrected we can assume that the rogue SCW in the middle is also well
calibrated.


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: Excellent (Xe line positions within 2% of ideal)

JEM-X2 rating: Exemplary (within 1% of ideal)

The JEM-X2 corrections are based on the JEM-X1 Fe calibration sources, since
all the Cd sources are now to weak to use.

CAO 18/12/2018