Gain Notes for Revolution 1144

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 was very strongly affected by raised hardware trigger counts,
suggesting solar activity which has been very common since coming out of solar
minimum. At the beginning of the revolution there is a steady increase in trigger
rate which doesn't fade out until late in the revolution.
 

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 else. The updated ISDC Instrument Characteristics
can be downloaded from
http://www.isdc.unige.ch/integral/download/osa_sw



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.

	
JEM-X1: 

The Xe line analysis performed using the IC table shows accetably good gain
correction with all except 18 science windows having a Xe level 
within 2% of the ideal, and only 6 SCWs worse than 3%. The first 2/3 of the
revolution show very uncertain fits with largely unrealistic widths, which
means the Xe line position is very poorly determined. The last 1/3 of the
revolution where widths are all very good, also has excellent energy correction
with all SCWs within 2% of the ideal, suggesting that where the Xe signal is
strong enough to measure, gain determination is good, suggesting that
it probably is good throughout the revolution, though this is hard to
determine where the Xe line is very weak.
As usual, it is recommended that users
avoid the first few science windows for energy-sensitive applications.


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: Results coming soon.

CAO 14/03/2012

	Gain Notes for Revolution 1144
	

JEM-X2: 

The Xe line analysis performed using the IC table shows acceptably good gain
correction with all except some weak, misfitted science windows having a Xe level 
within 3% of the ideal. As with JEM-X 1 it's unlikely a better energy calibration
would really help since there are a lot of SCWs here with poor fitted widths,
suggesting that the Xe line cannot be determined particularly well for much of
the revolution.
As usual however, it is recommended that users
avoid the first few science windows for energy-sensitive applications.

CAO 14/03/2012