Gain Notes for Revolution 1863

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.

N.B.: This was a very noise revolution due to after effects of the big solar flare.
Calibration spectra were noisy and gain history tables showed unexpected jumps
not related to temperature changes in the instrument. This meant that energy
determination verification with the Xe instrument lines appears much noisier
than usual with alot of misfitted points (points with negative or unrealistic
widths etc.). However, the end result is very good and can be used as for
any other revolution from an energy-sensitive perspective.
 

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: Correctly fitted points (as opposed to misfits) indicate that
gain determination is very good despite the noise, within 2-3% of ideal.


JEM-X2 rating: Ignoring misfits energy determination is very good (2-3%)
	except for the last two science windows. 

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 29/09/2017