Gain Notes for Revolution 1030 Gain Notes for Revolution 1030 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. 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="/". 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: For just this revolution and this unit the Xe line position with the original gain history table showed a very large sudden drop as though something had happened on the microstrip plate that had not affected the calibration areas in a similar way since there was nothing to indicate a problem in the calibration source peak channel positions. The IC table manages to correct this unusual problem to some extent, but the energy determination in the first half of the revolution is not nearly as good as it should be and users are warned not to use the first half of this revolution for energy sensitive applications. The Xe line analysis performed using the IC table shows acceptable gain correction with all science windows having a Xe level within 3-4% of the ideal. The two poorly corrected areas lie between IJD=4097.7-4097.9 and IJD = 4098.4-4098.6 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. . CAO 14/04/2011 JEM-X2: The Xe line analysis performed using the IC table shows good gain correction with all except the very first science windows having a Xe level within 2-3% of the ideal. As usual however, it is recommended that users avoid the first few science windows for energy-sensitive applications. CAO 05/04/2011