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ALFOSC has performed well with the exception of the occasional timeout
from the grism wheel. Normally this is easily solved by stopping the
user interface and initializing on restart, occasionally the telescope
must be brought to zenith first. The final cause of these timeouts is
not clear due to their sparsely intermittent nature, but is believed
to be linked to unevenly distributed weight when only partially
populated, and appears to depend on telescope altitude. Close
inspection has yielded no anomalies.
CUO/IJAF noted that the ALFOSC flange did not fit snugly to FASU due
to the absence of a mounting bolt at the detector end of the
instrument. The resulting lever arm made it impossible to completely
close the gap between the flange and FASU. This has been a known
problem at the telescope for some time and was not believed to be a
significant issue. However, CUO/IJAF were concerned that the FASU
flange would be permanently bent so a fitting was produced to allow
the inclusion of a mounting bolt near the detector. The flange and
FASU are now flush when the instrument is properly mounted
and no permanent
damage can be discerned
During January technical time ALFOSC was thoroughly cleaned and
inspected. A considerable amount of dust was removed from the
interior and most particularly from the upper surface of the folding
prism. The resulting flat field shows considerable improvement -
where there were as many as one hundred dust donuts, immediately after
the cleaning there were less than 10. Complete removal of dust was
not possible without dismounting the CCD, which was not considered
In collaboration with Per Kjaergaard (CUO), the MOS mode is now
nearing the condition at which it may be made available to the
community. We expect to announce this in the call for proposals made
in April and support runs in the semester beginning October 2001.
Remaining work is primarily in the area of documentation. Runs will
require significantly more support than usual, and we recommend a
restrained response to demand in the first instance. (JC)
Data has been collected over several months and is being reduced by
Andreas Jaunsen (ESO) as part of the gravitational lens monitoring
programme led by Jen Hjorth (CUO). Some results are already posted on
the NOT web pages. (AK)
New ND filters installed and calibrated (VP). New document set
available on web (AK). Data reduction programmes now available on web
page (AK). The ``circular polarimetry only'' mode has been tested and
reduction software written by A. Berdyugin is available.
There is no change in the disposition of HiRAC - observers are being
requested to use ALFOSC where possible and so far this has always been
the case. No attempt has been made to rectify the soaking problem due
to lack of manpower and the anticipated imminent arrival of MOSCA
which will make HiRAC redundant.
StanCam continues to operate without problems.
A new fibre-viewing mirror and mount have been installed in the
telescope instrument adapter, including new StanCam reimaging optics
to aid target acquisition. A new fibre mounting plate has been
installed. Target acquisition procedures have been established and
test observations made under real observing conditions.
Now FIES is ready for final commissioning: All hardware is installed.
Target acquisition procedures have been described and tested, and can
be easily carried out by the observer.
FIES still needs a new CCD, as the test-chip proved to have very high
dark current. The mounting of a new CCD will not interfere with normal
telescope operation. On the software side a smoother interface to
BIAS would be desirable but not critical. Also the instrument needs
to be put back on the telescope pier. Apart from this, FIES is ready
for use. (TD & FIES team)
One SOFIN CCD suffered mechanical destruction and both have been
replaced with a similar devices donated by Isaac Newton Group. (GC)
The mechanically destroyed engineering grade device has been replaced.
Before it is installed, the CUO/IJAF group are investigating detector
mount redesigns so as to avoid repeating the circumstances which
destroyed the first. A delivery date to La Palma is unknown at this
Five (U', B, V, R and SDSS z') of the interim filter set have been
received and test data collected in parallel with the ALFOSC zero point
See Director's report.
In line with the working group's recommended priorities, we have given
priority to obtaining state-of-the-art detectors first for MOSCA and
next for ALFOSC. The best candidates for MOSCA are currently Marconi
(ex-EEV) devices with integrated anti-fringing technology, but the
possibility of a good device (4k 4k monolithic) and price
from Fairchild prevent us from committing to Marconi.
Fairchild could also provide a replacement detector for ALFOSC.
All investigations of best-effort, wafer-run purchases have been
postponed in the apparent absence of a suitable path of manufacture,
packaging and test. Moreover, we are not aware of any suitable
partners available to share the expense and risk at this time.
See detailed status report from GC in Appendix B.
Progress is being made. A visiting student, Bjarne Andersen, will
assist with the project from mid-March to mid-June. It is hoped that
CUO/IJAF will integrate this design into their planned improvements to
Up: AiC Report to NOT
Tim Abbott, AiC
Wed Mar 21 12:56:05 GMT 2001