Gain Notes for Revolution 410
	
JEM-X1:

 A revolution with significant grey filtering that has in a few cases
badly affected the determination of the calibration line positions for the
weakest calibration source, number 4. (See `Uncorrected' gain history figure).
This is the first of several revolutions with observations of SCO X-1 and hence
the first to suffer from a problem whereby the fourth calibration source is so
weak that stray events from SCO X-1 are actually confused with calibration 
events. This effect is seen in SCO X-1 observations up to revolution 420, after
which new calibration processing software searched out this problem and
cut out lower energy events in the calibration spectra. Consequently, several
revolutions between 410 and 420 require the use of IC tables in which the
gain history is corrected offline for this problem.


CORRECTED WITH IC TABLE:
This problem is now fixed by using OSA 6.0 and later versions. The corrected
gain history table, with the outlying points corrected, is delivered to ISDC
as an instrument characteristics (IC) file. The analysis scripts can find these
IC files if one exists for a particular revolution, and use it instead of the
automatically generated file. The Xe line analysis using the IC table shows
a fine gain calibration with the average Xe position about 1% above the
expected value, which is  well within acceptable limits and the usual variation
of the instrument. 

If you do not have the latest IC package, you can download
the IC table from the last column of the table containing these notes:
[Corrected]ICGainHistory. This is a file with a name like
 JMX1_gainHistoryIC_revRRRR_VVV.fits.gz where RRRR is the revolution e.g. 0410,
and VVV is the version number, e.g. 001.
Save this somewhere suitable and unzip it:

\> gzip -d JMX1_gainHistoryIC_revRRRR_VVV.fits.gz

Then when running all the Science Windows you want to analyse in revolution 410,
set the input parameter COR_gainHist in the OSA GUI thus:
COR_gainHist = <path to saved file>JMX1_gainHistoryIC_revRRRR_VVV.fits.gz[JMX1-GAIN-OCL,1]

This is the complete DOL for the extension containing the corrected gain history
table. The gain smoothing and Xe line analysis shown in the Gain History
Archive table have been produced using this IC table.


JEM-X2: No data and no gain history for this unit


CAO 30/8/2007