THE UNITED KINGDOM INFRARED TELESCOPE
ANNUAL REPORT
2001-2002

5. Instrumentation Development: WFCAM

During semester 2001A the WFCAM team was also working on the VISTA project, and accordingly the WFCAM project slipped three months. The team focused on reaching design decisions in several key areas prior to the Preliminary Design Review (PDR). A 2kx2k IR Array Multiplexer was up and running in the test cryostat and an SDSU detector controller was selected. Tenders were issued for optics, detector controllers and the tip-tilt system. The autoguider design was fixed. Ordering and procurement of the main optics became the critical path items; the prices submitted by the optics suppliers were considerably higher than allowed for in the budget, and the lead times were longer than expected. Ways of reducing both cost and lead time were negotiated. When the WFCAM PDR was held in November 2001 many major tasks had been completed: six major optical items had been ordered; the detector controller specified and acceptance test procedures issued; filter mechanism parts had been selected and ordered; and secondary mirror tests had been successfully completed at the JAC.

In April 2002 tests showed that the proposed design for attenuating interference between the optical CCD guider and the infrared arrays would work. The formal agreement between National Astronomical Observatory of Japan (NAOJ) and PPARC, by which NAOJ will provide three Science Grade (SG) arrays, was signed in June 2002. The first SG array was delivered by Rockwell in March 2002 with a forecast for shipping the remaining arrays to the UK ATC around October 2002. This date was subsequently revised to February 2003. The SDSU controller was delayed due to technical problems. A speedier delivery option for the tertiary was purchased to allow more time for integration and testing before delivery.

In semester 2002B the first detector controller was delivered and the first SG array was characterised. Filter arms were cold tested. The vacuum vessel was delivered to the UK ATC and in February 2003 the first instrument cooldown was achieved. Optical elements remain critical path items and slippage in delivery of the corrector plate has delayed telescope commissioning of WFCAM into 2004. Rockwell have delivered three SG arrays at the time of writing; integration and testing will commence with the delivered arrays. The project cost is currently forecast at £4249k which is within the total project budget, including contingency.

To ensure that the required software is completed on time, the JAC will manage the Cambridge Astronomical Survey Unit and Wide Field Astronomy Unit at the UK ATC who are responsible for the pipeline data analysis and science archive, respectively. The UK ATC will produce an engineering data pipeline for commissioning the instrument.