Gain Notes for Revolution 278
	
JEM-X1: A completely ordinary revolution, though with a very short activation
period due to the background radiation level that caused the instrument to
be switched off for all of Rev 277. Gain smoothing is fine except immediately 
after switch-on where small gain decreases precede the gain increase. All data
from this revolution should be useable though the first hour or so after 
activation may have slightly poorer energy determination due to the pronounced
`hooks' after main switch-on.
First two data points on each data set are the  pre-switch on with High 
Voltage 3 steps below its nominal value. 

Xe Analysis: It can be seen that the Xe line falls with less than 1 keV of
its expected position, and hence the gain correction has worked as well as is
currently expected. There is no sign of hidden gain suppression on the plate,
even at the end of the revolution where the instrument was hastily turned off
just as the solar background was rising sharply. As expected, the first 3
science windows show the greatest deviation in the Xe line position and should 
be treated with some caution when interpreting changes in spectral features.

CAO 17/11/2006