IMACS progress report no. 3 B. Bigelow 1 July 1998 The objectives for June were: I.P. A. Revise instrument and optics budgets in preparation for the design review in July. I.P. B. Produce a preliminary project schedule in preparation for the design review in July. Done C. Complete conceptual designs for the instrument structure, housing, and assembly/test stand. I.P. D. Review applications for the mechanical engineering position. Schedule interviews as appropriate. I.P. E. Place orders for optical glass, CaF2, fused silica. Start optical, thermal, flexure, and focus analyses Done F. Investigate design and fabrication of a profilometer for asphere fabrication. Objectives for July: A. Present IMACS specifications, budget, and schedule for LCO operations committee meeting on 14 July 1998. B. Schedule and begin preparations for preliminary design review (PDR) planned for late August or early September. C. Complete interviews and select a candidate for the mechanical engineer position. D. Review and finalize instrument structure conceptual design. E. Continue research into slit mask fabrication techniques 1) Project budgets and schedule A comprehensive optics budget was produced by Sutin and Harland Epps. This budget is larger than previous estimates in both the realism and dollar categories. The new optics budget will be incorporated in the instrument budget for presentation at the July 14th IMACS meeting (1:30 PM). The project schedule is still in progress, and will be presented at the IMACS meeting with the project budget. 2) Conceptual designs Two space frame structure designs (Bigelow), and a plate weldment design (by Steve Gunnels) were completed in June. Jerry Nelson (Lick Obs.) has agreed to review the structure designs and to suggest possible ways for combining or improving the designs. 3) Staffing Approximately ten applications were received in June for the IMACS mechanical engineer position. Two mechanical engineers were interviewed in June, and a third candidate will be here on 7/10/98. I hope to have a new engineer on board by the end of August. 4) Optics orders See attached summary by Sutin. 5) Profilometer Sutin and Bigelow produced a conceptual design for a profilometer (for measuring the short camera aspheres), based on a Kyocera air bearing slide, Zygo distance-measuring interferometers, and Aerotech motion stages. Sutin produced a cost estimate, and we are looking for a consultant to take the concept to the next level for possible fund raising exercises with Dan Fabricant (CFA). 6) CCDs and guide cameras The electronic design process for the CCD mosaic and controller awaits completion of the guide camera design work. Circuit board design for the TV cameras continued through June, and Burley reports that PCBs should be completed by the end of July. Part ordering has started and deliveries should begin this month. Fabrication of the mechanical prototype for the guide camera was planned for June, but has not yet started. The prototype is now scheduled for fabrication in July. Discussions were held with Gerry Lupino regarding purchasing the CCD array cryostat and detector head from Gerry's company in Honolulu. The price would be competitive with IR Labs, with the additional benefit of an already demonstrated design with a 24 hour-plus hold time. Lupino also indicated that OCIW could consider purchasing Lincoln Labs / MIT CCDs with 2-3 e- readout noise at very reasonable prices. Recent yields through the UH consortium purchase have been as high as 90%, and the performance of the chips is reported at the Lick CCD lab website (htpp://gardiner.ucolick.org:80/~ccdev/). 7) Mechanics Three structure designs were completed in June, one of which can be seen on the wall across from the IMACS optics layout. A weight estimate for the instrument was produced for use in finite element modeling of the instrument structure designs. The total rotating weight of IMACS is estimated to be 1845 Kg (4060 lbs). The centroid of the instrument lies very near the Nasmyth optical axis, which will minimize the need for additional balancing mass. Several fabrication methods are currently being explored for fabrication of the 24" diameter slit masks. Metal spinning and stamping are candidates for making the masks themselves, and lasers, abrasive jet cutters, electrical discharge machining (EDM) and precision slitting saws are all being examined for cutting the multi-slits. 8) Electronics There was no change in IMACS electronics this month. Impressive progress is being made on the electronics for Persson's IR instrument, which will probably provide a good model for the IMACS electronics. 9) Software Christoph Birk has produced a preliminary design for the IMACS software system architecture, based on UNIX. As with electronics above, the IMACS software package should benefit from Birk's current work for Persson's project. 10) Optics (summary) Optical Report for June, 1998 Brian Sutin ------------------------------------------------------------------- Tasks Scheduled for June: DONE A) Complete model of IMACS explored for owies DONE B) CaF2 order DONE C) Estimate cost of profilometer DONE D) Estimate overall optical budget STARTED E) Ohara glass order STARTED F) Prepare for Fused Silica Order, grating order, some grisms G) Start preparing for thermal analysis H) Start checking which elements are best for focus/flexure control ------------------------------------------------------------------- Tasks Scheduled for July: A) Finish Ohara glass order B) Write up complete profilometer proposal C) RFQ for Fused Silica D) Prepare for grating, grism order E) Start preparing for thermal analysis F) Start checking which elements are best for focus/flexure control -------------------------------------------------------------------