Gain Notes for Revolution 1114


The results shown as 'uncorrected' show the Xe line analysis results as they
are direct from the ISDC automatic calibration and correction pipeline. They
show just how bad the non-IC table results can be, though admittedly this is
a fairly extreme example (why show you something boring?). 

The poor results here are due to several factors:
1) Differential aging of the microstrip plate in general compared to the
   heavily irradiated calibration spectra areas on the plate
2) Increased sensitivity to temeprature with age
3) Non-linear temperature effects due to aging of the instruments
4) The growing sensitivity of the instruments to event rates - a real problem
   now that the solar activity is increasing
5) Increasing incidence of gain suppression that we can't clearly attribute
   to changes in housekeeping values.

While it the ISDC calibration pipeline has been updated to cope with these
effects to a certain extent, the best solution is to have each revolution
corrected individually offline and IC tables delivered to ISDC for distribution
to the users. This ensures the best results for every single revolution and
allows us to constantly tweek the needed corrections as the instruments age.

To use the data from  all the late mission revolutions, be sure that your 
collection of IC tables from ISDC is uptodate, and use these tables with
OSA8, or a later version, starting from the COR level in the analysis.