Gain Notes for Revolution 1587

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.

NB!!!!! This revolution is heavily affected by greyfiltering for the last half of
the revolution and the energy determination may be 10% or more from the
ideal. However this is very hard to determine or to correct for since there 
is a lack of both calibration data and verification events, thanks to the grey 
filtering. Users must be aware that the energy determination here is very 
uncertain between and hence a BAD_RESPONSE BTI is declared between
 IJD = 5735.8 and 5737.0. This BTI can be overriden by experienced OSA users.
 
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: 

The Xe line analysis performed using the IC table shows excellent gain
correction with all science windows in the first half of the revolution
 having a Xe level within 2% of the ideal, except for the early settling points. 
During the second half of the revolution the energy determination is probably
about 10% on either side of the ideal.
As usual, it is recommended that users avoid the first few science 
windows for energy-sensitive applications (automatically removed by OSA 10.0).


JEM-X2: 

Idenical remarks as for JEM-X1, but energy determination uncertainty may well 
be greater than 10%.

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 7/10/2015