SXT STATUS REPORT FROM ISAS
Thursday, 16 July 1992

The Yohkoh mission and SXT continue to function well.  Solar activity
has been relatively low the past few weeks, but a couple of active
regions (AR 7220-7220) that have now merged into one large region has
provided several C flares and one X flare that was observed by the
spacecraft last week.  Instrument operations have gone very smoothly
during the past few month.  Last week we lost one orbit's worth of
data because of a commanding error caused by a BCS calibration sequence
during the preceding spacecraft night.  But apart from this, the data
acquired with the SXT has been nearly continuous. 

This week we have been visited on different occasions by US scientists
who are attending the Astro-D meetings. 

Last week Gary Linford ended his tour of duty at ISAS.  Today, Sam Freeland
arrived to replace Gary.  Sam will spend the next three months as ISAS.
Mons Morrison also arrived for a brief visit with the specific purpose to
attend the software meeting (see below).


MEETINGS

Last month several of us (Prof. Y. Uchida, Drs. S. Tsuneta, T. Kosugi, and
myself) attended the Symposium in Palermo which was held in memory of
G. Vaiana who passed away last summer.  The meeting attendants were mostly
from the Cool Stars community and were seeing presentations of Yohkoh data
for the first time.  Many compliments about the quality of the SXT data
were received and there was especially a lot of interest in the video.


Today at ISAS there were two important meetings held in D-toh.  The first
was a software meeting attended by Nitta, Freeland, Bentley, Watanabe, Hudson, 
Tsuneta, Morrison, Kosugi, Sakao, and Lemen.  We discussed the use of the
reformatted data base by the various instruments and status of the 
the general software as well as software developed for the specific 
instruments.  Additional splinter sessions are scheduled to occur later this
week.

Later a meeting of the Yohkoh Bureau was held involving Bentley, Watanabe,
Hudson, Tsuneta, Sterling, Kosugi, and Lemen.  We spent the majority of the
time discussing the merits and the use of the Team Bulletin Board (TeamBB).
It was decided that Lemen will send out a notice which will clarify its use
and encourage a wider participation.  Specifically, the following points
will be emphasized:
		(a) The more specific the topic the better.
		(b) Appearance of a topic on the TeamBB is required prior
		    it being submitted for publication as a paper.
		(c) Topics will be dropped if there is no activity in 6 months.
		(d) The appearance of a topic does not necessarily determine 
		    the authorship list.
		(e) It was recommended that specific event dates be given
		    in the titles of topics, or if it is more appropriate,
		    in the text itself.  This is because various individuals
		    might be interested in the same event, even though they
		    may not decide to participate in the same science topics.


SPECIAL EXPERIMENTS

Last month the CCD TEC was turned off for two days in order to "bake" off 
the foreign substance that tends to freeze onto the surface of the CCD.
Loren Acton recently analyzed this data and circulated a report.  As it has
been observed previously, the images in the narrow band filter were observed
to be sharper following this action.  

Two weeks ago we ran a special experiment to try to obtain higher time
resolution studies of active region transient brightenings and micro
flares.  A 1x1 OR was selected for the thin and thick Al filters.  This
experiment was run in FFI-dominant mode for one orbit.  It appears the
the sequence worked very well and may yield interesting results.  As
soon as I have completed the analysis of this data set, it may be
appropriate to try repeating the experiment with even higher time resolution
in PFI-dominant mode.  We have plans to run other special experiments
as soon as the solar conditions permit it.  In particular, we plan to 
do an experiment which is designed to study an X-ray bright-point with
higher time resolution and we also we attempt to obtain better observations
of coronal holes for the purpose of determining their temperature.

--  End of Report:    J. R. Lemen --