Gain Notes for Revolution 903
	
JEM-X2: 

During this Crab revolution the weaker calibration sources meant the
software had a problem distinguishing calibration photons and Crab photons,
with the result that the automaticly produced gain history table had some
very poor points that threw off the gain smoothing procedure.

To get optimal results with this revolution it is necessary to use the IC gain history
table that has been created offline at DNSC, instead of the gain history table
created automatically by OSA. If you have the newest package of IC files from ISDC
and these are correctly installed, OSA will find the IC gain history table automatically
and you don't need to do anything. However, if you don't have the IC gain table
package from ISDC you can download the table from the gain history archive by
anonymous ftp through the link provided. Download the table to some suitable
subdirectory for your analysis, then set the hidden OSA parameter gainHist:
gainHist="<my subdirectory>/<IC filename>". These files are used instead of the
automatically generated gain history tables wherever there has been an unusual or
non-linear behaviour of the detector gain.

Results shown are produced with the IC table, and confirm that the Xe line
now lies within about 1% of the ideal value for all except the very first
SCWs. As always, it is recommended that users avoid the first few SCWs in
the revolution since the instrument is in the process of warming up and
stabilizing the charge distribution in the microstrip plate.


CAO 16/03/2010

	Gain Notes for Revolution 903
	
JEM-X1: 

This unit was switched on just for this calibration revolution, which means the beginning
of the revolution shows all the disadvantages of activating the instrument after a long
dormant period, which requires gain settling to occur before reliable flux and gain
corrections can be performed. Therefore the first part of this revolution has been declared
a Bad Time Interval, and will be ignored by the OSA processing. 
The BTI is from IJD = 3717.4 to 3718.0.

This is a Crab calibration revolution with very high gain (upto 28 
channels per keV).
To get optimal results with this revolution it is necessary to use the IC gain history
table that has been created offline at DNSC, instead of the gain history table
created automatically by OSA. If you have the newest package of IC files from ISDC
and these are correctly installed, OSA will find the IC gain history table automatically
and you don't need to do anything. However, if you don't have the IC gain table
package from ISDC you can download the table from the gain history archive by
anonymous ftp through the link provided. Download the table to some suitable
subdirectory for your analysis, then set the hidden OSA parameter gainHist:
gainHist="<my subdirectory>/<IC filename>". These files are used instead of the
automatically generated gain history tables wherever there has been an unusual or
non-linear behaviour of the detector gain.


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.

Results produced with the IC gain history table show that energy correction
is within 2% of the ideal for all SCWs except the first ones. As always,
users are advised to avoid the first SCWs for energy-sensitive applications,
since the instruments are still warming up and settling down during this
period.




CAO 29/04/2010