SXT Status Report
			21 August - 27 August 1995 (Week 34)
                                    ---------

                                    Mark Weber 
                                    28-Aug-95


   I went to Akihabara last week, which is THE place for Japanese
electronics and related devices. I saw hi-res tvs, electrostatic
loudspeakers, and lots of other neat stuff. I was accompanied by a
fellow student from Montana, whom I also took on a tour of ISAS. It 
was a strange reversal for me to be explaining SXT operations to 
someone else.


SOLAR ACTIVITY

The Sun has mustered its resources to achieve an X-ray level of
months past. AR 7901 has increased its area considerably. AR 7902
has managed to produce at least one C-class event. And AR 7903,
just arrived over the east limb, has also contributed to X-ray
emissions. GOES data shows an obvious rise in radiation over a
period of about a day. It is difficult to say if this is mostly due
to de-occultation of AR 7903.
  

SXT INSTRUMENT STATUS

One of SXT's calibration issues has changed in a significant but
recoverable manner. On November 13, 1992, a hole was made in the
SXT aperture filter, permitting straylight to penetrate to the
CCD. Calibration techniques were developed to compensate for the
effect of this on SXT images. On August 18, 1995, the straylight
increased by a factor of three, probably due to a further failure
of the entrance filter. The straylight level has been stable since
then, and is "still well within the range of correction". The
project of adjusting the calibration process is well under way.

In all other respects, the SXT has been functioning properly.


CALIBRATION STATUS

Currently, calibration efforts are being applied towards
quantifying the recent increase in the stray light. Much progress
has been made in this direction in very little time. Already we
can compensate full-frame images for a couple of the diagnostic
filters.


PASS CONFLICTS

We lost a total of nine (9) passes last week due to conflicts 
with ASCA.


CAMPAIGNS

  - SPARTAN
     Spartan 201-03 launch has been scheduled for August 31. The
     satellite will be deployed "on September 1 at 11:40 EDT to
     begin almost 45 hours of observations."
     As of August 26, the SXT Team is still considering its
     observing plan. The fact that Spartan will be operating over
     a weekend introduces some complications in our scheduling.

   - POLAR RAY CAMPAIGN
     On 25-Aug-95, SXT took PFIs of the solar north pole and low
     corona. This was mainly to provide a test run for SXT, and
     to provide some preliminary data for Koutchmy-san and
     Hara-san so that they may further formulate their requests for
     SXT observations. It is possible that another short observing
     period may be fixed for this week.

   - FILAMENT OBSERVATIONS
     SXT has been assisting Hawaii with filament observations, but
     there has of late been a lack of obvious targets. Regular
     communications between ISAS and Mees have been maintained.

   - X-RAY BRIGHT POINTS
     Dr. Karen Harvey has proposed an XBP campaign for September
     15-23, 1995. Discussions on general matters have ensued.


SCIENCE

George Roumeliotis (Stanford U.) visited and gave a seminar on image
reconstruction for SXT. By using new tools for this purpose, he has
found a rather clear example of what appears to be a loop-loop
interaction. Alas for our preconceptions about this, the point of
reconnection seems to be dark, rather than bright. This is
consistent with the difficult time we have had in general to prove
the existence of macroscopic reconnection via the SXT data, and
offers a clear challenge to others to work on the difficult
questions of image interpretation (including resolution
enhancement) in quantitative ways.

This visit was timely, because Y. Hanaoka was one of the SSOC
tohbans this week. He has now written a second paper on SXT data
analysis for loop-loop interactions. This made the traditional
farewell sushi lunch all the more interesting!


SEMINARS

   - The seminar this week was given by George Roumeliotis of
     Stanford University. The title was "IRIS: An Algorithm for the
     Reconstruction of SXT Images." The visual examples were
     impressive.
                 

PERSONNEL

Hugh Hudson returned from a "high-energy" meeting at Goddard. 
Kevin Reardon joins us at ISAS from the University of Hawaii for 
several weeks of (hopefully) fruitful research.


Week 34 Tohban:
   SSOC: Hanaoka and Ueno
   KSC:  Sato and Hori
SXT Chief Observer:
   M. Weber
SXT Systems and Data Engineer:
   G. Slater