The US Gemini instrument program has been active during the past few months. The Gemini Mid-Infrared Imager (MIRI) Announcement of Opportunity netted several Letters of Intent to Propose. Requests for Proposals for the 8-26 µm single plate scale imager were distributed 26 June, with a proposal due date of 8 August. The proposals will be reviewed and evaluated in August, with a goal of awarding a contract by November. The MIRI is scheduled to be delivered to the Gemini South site on Cerro Pachon in late 2000. The instrument concept is for an inexpensive, yet capable imager for the mid-infrared region with a minimal upgrade path. Experience with this instrument in the south and with Michelle, an imaging mid-IR spectrograph built by ROE and shared between Gemini and UKIRT in the north, will most likely define the requirements for future Gemini instruments operating in the mid-IR.
The Gemini Near Infrared Imager (NIRI), being built by the Institute for Astronomy of the University of Hawaii, held a two-day Critical Design Review in mid-May. The review committee, chaired by Ian McLean/UCLA, "... felt that the NIRI Team had done an excellent job and we wish to offer our congratulations. Well done! The optical design and tolerance analysis appears to be very good and should lead (potentially) to remarkable Strehl ratios." This 1-5 µm imager has three plate scales and will be the commissioning instrument for the Gemini North telescope on Mauna Kea. The CDR was followed by a safety review to ensure that the NIRI will not harm personnel, other equipment, or itself during its operational lifetime. The NIRI team has ordered its optics, and team leader Klaus Hodapp expects to deliver the instrument in a little over a year.
NOAO's Engineering and Technical Services project team is making good progress on the Gemini Near Infrared Spectrograph (GNIRS). The team is on schedule with the detailed design, aiming for an Autumn Critical Design Review. Over 200 of the approximately 700 fabrication drawings are complete and have been checked, and the team is making excellent progress in the structural detailed design with the goal of meeting the performance requirements while holding the weight to only two metric tons. All mechanisms are in their final stages of detailed design, with designers interacting with engineers to analyze the designs for flexure and other performance goals. NOAO will deliver the instrument in early 2000.
NOAO is also building the InSb science detector array controllers for both NIRI and GNIRS. The first controller, destined for the NIRI, began hardware integration testing in June and system testing in July. Early results indicate it will have very low noise, and with 32 high speed A/D converters, Instrument Scientist Mike Merrill expects it to meet NIRI's speed requirements. The NIRI controller is scheduled for delivery in October, while the GNIRS team receives its controller a year later.
Hughes Santa Barbara Research Center is on track in its foundry run of 1024 X 1024 InSb arrays for Gemini's near infrared instruments. NOAO is overseeing this contract, which has a goal of obtaining a science grade array for each of the two near IR Gemini instruments, plus a spare. Recent SBRC results in other programs are encouraging for the Gemini run.
NOAO is also organizing the effort to provide the CCDs and controllers for the focal planes of the Gemini optical spectrographs. CCD controllers are being obtained from Robert Leach at San Diego State University. The CCDs, 2048 × 4608 with 13.5 µm pixels, are being purchased from EEV in the UK. The software that connects the controllers to the Gemini instrument control and data handling systems will be a joint effort of the Royal Observatories and NOAO.
Mark Trueblood, Todd Boroson