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To: head@head-cfa.harvard.edu
Subject: HRC Status #4
Date: Tue, 25 Mar 1997 05:53:53 +0000
From: "Stephen S. Murray"
Status: R
Since the last status report HRC operations at XRCF have been fairly routine. We
completed a series of effective area measurements with the central segment of
the HRC-S and the detector is behaving rather well. We were able to determine
the focval plane position for HRC-S using shutter tests to an accuracy of about
100 microns (two tests agree) and determine that the HRC-S is about 600 microns
in front of HRC-I (we expected a bit less - 300 microns) but this is well within
the tolerance buildup.
The count rate linearity for the HRC-S is quite good. Up to about 10ct/sec in a
focused beam we see good linearity with the input flux. There is no evidence of
any depression in detection efficiency in the center of the image.
Using the Ring Focus of the HRMA we were able to map out the location of the
HESF flats on the HRC-S. THese are complex data to analyze fully. Jeremy Drake
is working on the data with the HRC Team. We will know the relative position of
the flats in time to carry out the reflectivity measurement planned over the
rest of the calibration. It is good to note that the flats do not reflect very
much at 2.5 keV were the ring focus tests were done!
Our last "first light" was today when the HRC-S and LETG were finally operated
together. We have some very beautiful and informative images that were taken
spanning energies from 7 keV down to about 1.5 keV. The mutilple orders (at
least to 9-th) there seen, and the supression of second order relative to third
is quite dramatic. we could spend a lot of time fully analyzing these images.
When these higher energy tests are completed we will change out the DCM for the
C-Ka source and begin again with the HRC-I in place.
Dr. Stephen S. Murray - Sr. Astrophysicist
Associate Director - High Energy Astrophysics Division
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Smithsonian Astrophysical Observatory__| phone: (617) 495-7205
High Energy Astrophysics Division __| fax: (617) 495-7356
60 Garden Street, MS-2 __| email: ssm@head-cfa.harvard.edu
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