Gain Notes for Revolution 1473

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 shows several sharp dips in gain where the countrate
spikes, and the general plate gain dips are somewhat delayed compared to
the calibration spectra dips, leading to a slight gain mismatch during these
periods - also we can expect to see a non-linear response to these transient
events that will also lead to poor gain correction during these periods.

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.

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: 

NB: This revolution shows several sharp dips in gain where the countrate
spikes, and the general plate gain dips are somewhat delayed compared to
the calibration spectra dips, leading to a slight gain mismatch during these
periods - also we can expect to see a non-linear response to these transient
events that will also lead to poor gain correction during these periods.

The Xe line analysis performed using the IC table shows very good to 
acceptable gain correction with all science windows (taken 1 at a time) having a Xe level 
within 2-5% of the ideal, except for the very first SCWs. Outside of the
periods mentioned above, gain correction is very good.
As usual, it is recommended that users avoid the first few science 
windows for energy-sensitive applications (automatically removed by OSA 10.0).


Calibration source number 4 (purple/orange) is no longer
used for calibration purposes since an anode strip directly under the source
has broken and no useable signal comes from this area of the detector any
longer.



JEM-X2: 

The Xe line analysis performed using the IC table shows very good gain
correction with all science windows (taken 1 at a time) having a Xe level 
within 2-5% of the ideal, except for the first SCWS. 
As usual, it is recommended that users avoid the first few science 
windows for energy-sensitive applications (automatically removed by OSA 10.0).


As with JEM-X1, source 4 is no longer used for energy correction purposes due
to a broken anode strip

CAO 01/12/2014