JLS Current Status

Date: 15 February 2008

TELESCOPE	Nothing to report. In the two weeks since the last report there has been a lot of time lost to weather. At the moment, Mauna Kea is living up to its name.
HARP/ACSIS	There has not been a lot of progress here with the bad weather preventing access to the telescope and instruments for a number of nights. The current status of HARP is summarised below: Receptor H03 is missing from the cryostat. Receptor H14 is currently unusable due to large oscillations in the mixer. Receptors H09 and H12 are operational but have high resistance in series with the junction. For H09, this resistance has been present since the instrument was delivered. For H12, its high resistance appeared after a scheduled warm up in September. An interim solution has been to increase the bias voltage on these receptors, with minimal effect on data quality. The dewar is showing temperature drifts which are affecting the performance of the mixers. The compressor and cold-head are suspected to be the cause - the latter may need to be replaced in April.
CALIBRATION	There have been variations in calibrations since December. Investigations are ongoing to determine the cause and resolution of these. Receptor-to-receptor gain variations have been reported whose cause are being investigated. These variations are frequency dependent (12CO tunings perform much better than 13CO, for instance).
PROGRESS	We are nearing the end of the February JLS observing block which is being hosted by the SLS. See the summit occupancy page for February 2008 to see who the observers are. At the time of writing, there is one night left of observing. Since the weather broke at the end of last weekend (10th Feb HST) we have seen a range of weather (between and including bands 1 and 4) during which we were able to observe in all queues. Up to the time of writing, there have been a total of 72 hours available in the JLS block of which 37.9 hours have been spent observing for the JLS. Specifically, 21.2 hours were spent observing for NGS, 5.4 hours for GBS and 11.4 hours for SLS. Quality assurance of this data by the teams is now needed. The observing seems to have gone smoothly. The weather was at times too good for the JLS projects and observations from the queue were executed. In fact, 16.65 hours were spent observing projects from the CN queue and 4 hours were spent on E&C work. The next observing block, hosted by GBS, is due to start at the end of the month. The current progress is shown in the bar charts below, illustrating the amount of time charged to each survey and the current completion rate. For reference, the JLS allocations are given here.
ARCHIVED REPORTS	An archive of previous JLS status reports is accesible from the links below: 31 January 2008

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