Gain Notes for Revolution 208
	
JEM-X1: A quite normal revolution with fine gain smoothing. All data from this
revolution should be useable. 
The first few points in each curve are from the partial switch-on at the
beginning of the revolution, for which HV is set 3 steps below its nominal
value.
All sources show clear fast relaxation due to charging of the plate at the
beginning of the orbit. This causes a rapid gain decay just after switch on.

JEM-X2: The otherwise dormant unit was activated for the Crab calibration, and
we clearly see the strong gain increase associated with the rapid aging of the
unit after its long rest. During the rest period the ion migration in the
glass of the microstrip plate relaxes and the gain of the detector returns to
its launch value. However, as soon as the HV is switched on again the plate
undergoes in a half day, or so, the ion migration and gain increase that had
otherwise taken the whole mission to occur. Otherwise, this is a perfectly
ordinary revolution with fine gain fitting, and all data from this revolution
should be useable, except maybe for the very first hour where the hook of a
small gain decay is not well fitted on any of the sources.
As with JEM-X1, the first couple of points on each curve are the partial
switch-on of the unit.

The first part of this revolution where the gain and SPAG are changing very
rapidly is designated a Bad Time Interval by ISDC and science data from this
time period will be disregarded by the analysis software. The BTI is:
IJD= 1638.60 to 1639.30.

CAO 10/11/2006


Xe line analysis for JEM-X2 added to archive during creation of new JEM-X2
IMOD epochs with new reference channels (Epochs 12 and 13).

CAO 19/10/2007