|
Documentation > SXT Observation Notes > this page |
Image name: Diffuser_941108.png (click image to enlarge)
Image size: 426.548 KB (1024x512)
Date submitted: 08-Nov-1994
CHANGE IN SXT DIFFUSER IMAGE IN 7 MONTHS. The image on the left is a flattened (using SXT_DIFFUSER2.PRO) diffuser image made from the following 2 diffuser images. 0 8-NOV-94 04:21:30 QT/H Diffu/Open Half Norm L 4 2.9 512x512 1 8-NOV-94 04:23:38 QT/H Diffu/Open Half Norm C 4 2.9 512x512 This images looks very much like the comparable image from 26-APR-94. The image on the fight is a difference image of restored SXT diffuser images from 8-Nov-94 and 26-Apr-94. Over this interval the total diffuser signal increased by 3.4% but dark frames have not been subtracted before taking the difference so it is possible that some of this increase is dark signal. The dark signal for this exposure is about 1.5% of the total signal so it is certain that most of the increase is real -- as is also revealed in the SLS plots. Note the various "absorption" features corresponding to x-ray damage as well as the light areas corresponding to possible annealing effects and the large circular feature that probably corresponds to some detail in illumination pattern of the UV flood light. The regions of greatest increase in x-ray damage are the large diffuse patch on the disk in the NW and the very compact feature on the NW limb. The damage here has resulted in about a 1% effect in the diffuser signal. By and large, this is an encouraging result and indicates that it is probably OK to leave the Yohkoh pointing as is for the time being. Loren W. Acton 8-Nov-94
