Gain Notes for Revolution 1864 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. N.B.: This was a very noisy revolution with unexpected jumps in the gain history table and several science windows for which Xe line positions could not be fitted. However the final energy determination is rated good where the Xe line can be seen, and no special consideration should be taken for energy-specific applications, though the energy resolution will be somewhat degraded throughout. To get optimal results with this revolution it is necessary to use the IC gain history. See notes in revolutions prior to revolution 1433 to find out how to do this if you don't already know. All offline gain/energy corrections (including the IC tables) are based on the two Fe calibration sources in JEM-X1, for both units. Latest OSA software (version 10 and higher) automatically cuts out the first Science windows of data from each revolution to ensure that people do not use data from the instrument-settling period. This process can be overruled, but only by experienced users. JEM-X1 rating: For correctly fitted Xe peaks results are good, within 3-4% of ideal. (Misfit are indicated by their unrealistic and negative widths) JEM-X2 rating: Good, with about 4% of ideal. The JEM-X2 corrections are based on the JEM-X1 Fe calibration sources, since all the Cd sources are now to weak to use. CAO 29/09/2017