Gain Notes for Revolution 1670

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 contains one autonomous switch-off and a second switch-on due to
high background particle counts. But this has not affected the energy correction in any
significant way, since extra settling time etc. are taken care of in the Instrument
Characteristics (IC) gain history table produced off line and deliver to ISDC.
 

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 very good gain
correction with all science windows (taken 2 at a time) having a Xe level 
within about 3% of the ideal, except for the very first settling points. Most
points lie well within 1% of 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: 

Identical comments as for JEM-X1.

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 28/04/2016