THE UNITED KINGDOM INFRARED TELESCOPE
ANNUAL REPORT
2000

4. Approved Programme: Instrumentation Development

4.1. Michelle

The mid-infrared imager and spectrometer Michelle had made slow progress in 1999. However in early 2000 progress with several mechanical problems allowed system testing to begin in earnest at the UKATC. In April 2000 major improvements in read noise were made by correction of problems with the warm electronics; deliverable read noise was achieved in June 2000. The EDICT controller was used successfully with all the motors in January 2000. The full ORAC spine, including the DR, became operational in December 2000. Optical performance underwent several improvements, including corrections to the distortion of the toroidal mirror in the imager and correction of flexure-related and vignetting effects; deliverable performance was achieved in early 2001. A photometer and quantitative model allowed detection and correction of light leaks, and thermal control of the optics was improved, such that overall background was at a deliverable level by October 2000. Similar steady progress was made with improvements to the mechanical systems, which had generated many problems. The grating exchange mechanism underwent extensive modifications before a successful cooldown in October 2000. Flexure problems were systematically attacked but remained an issue until just before acceptance tests were scheduled in May 2001.

4.2. The UKIRT Imager Spectrometer UIST

UIST's progress was slowed by software and electronic effort being drawn to Michelle in the latter's big push to completion. The optics were in hand by mid-2000, although some grisms were damaged in shipping. The image slicer components for the Integral Field Unit were delivered by October 2000 and while some problems remained, the system offers acceptable performance, with a 33 6 field. Some testing was achieved with the engineering 512512 array and several mechanisms were successfully qualified during 2000. Early in 2001 the first cooldown with the complete opto-mechanical system was achieved.

4.3 Wide-Field Camera (WFCAM) and Large-Scale Surveys

Four large surveys emerged as priorities for WFCAM and science coordinators were identified. It is expected that the primary surveys will take seven years to complete if they have access to 30% of available UKIRT time. A formal Memorandum of Understanding is under discussion with Subaru for provision of arrays for WFCAM. Design work on the instrument continued and a test cryostat was set up in 2000.