Gain Notes for Revolution 1708

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 revolution ends with a SCO X-1 observation that causes strong
non-linear gain suppression and grey filtering: see notes for previous revolution
1707 which also contains a SCO X-1 observation.
 

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 (taken 2 at a time) in the pre-SCO X-1
part of the revolution (prior to IJD= 6058.1) with all these points
having a Xe level within 1-2% of the ideal, except for the settling points. 
In the SCO X-1 part of the revolution, wherever there is a good fit to the
Xe line (Position in line with its neighbours and a realistic width), the
data also look excellent, with all the points within 1-2% of ideal. A number of
misfitted points in this period indicate that verification of the gain correction
is compromised by grey filtering, but it is safe to assume that these SCWs have
just a good gain correction as their neighbours.
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: 

The same comments as for JEM-X1 above.
As usual however, it is recommended that users avoid the first few science 
windows for energy-sensitive applications (automatically removed by OSA 10.0).

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 03/08/2016