IMACS progress report no. 4 B. Bigelow 31 July 1998 The objectives for July were: Done A. Present IMACS specification, budget, and schedule for LCO operations committee meeting on 14 July 1998. I.P. B. Schedule and begin preparations for a design review planned for late August or early September. I.P. C. Complete interviews and select a candidate for the mechanical engineer position. I.P. D. Review and finalize instrument structure conceptual design. I.P. E. Continue research into slit mask fabrication techniques Objective for August: A. Continue preparations for design review to occur in late Sept. B. Complete recruitment for a mechanical engineer C. Complete instrument structure concept development D. Continue slit mask fabrication development E. Begin fabrication of a full scale mechanical instrument model F. Distribute first version of the current project schedule I have attached an optics report from Brian Sutin and a guide camera report from Greg Burley below. 1) Project scope, budget, and schedule The current instrument specification and schedule were presented to the Magellan SAC in Detroit on 7/12, and, with the budget, to the LCO operations committee on 7/14. The instrument specification was accepted, but with recognition that there is not currently funding to complete the instrument. It was agreed that glass should be ordered for the long camera and collimator, and the the preliminary design phase should start as planned following a design review in September. Once the preliminary design and optics RFQ phases are completed (Jan 1999), detailed budget and schedule revisions and a start/no-start decision for the short camera will be made. 2) Design Reviews A design review, including exterior reviewers, will be held in late September. The objective of the meeting will be get a reality check on the specifications and conceptual designs for the mechanical aspects of the instrument. Useful suggestions from the reviewers will be incorporated in the subsystem specifications, and used to guide the preliminary design work starting in September and October. A second design review is tentatively scheduled for January 1999, in which the preliminary designs will be reviewed again prior to starting final design and fabrication work. 3) Mechanical Engineer recruitment A mechanical engineer was interviewed 7/9 and 7/10, and a job offer was made on 7/16. I am hopeful that we will successfully conclude negotiations with the candidate by mid-August. I will be interviewing another candidate in this month, while visiting Gerry Lupino's CCD lab at UH. A third candidate, most recently from the SDSS project, is also a possibility. 4) Conceptual designs Two space frame structure designs (Bigelow), and a plate weldment design (Steve Gunnels) are being developed. On 7/15, Gunnels presented a preliminary finite element analysis of the monocoque structure which showed the feasibility of the design. Jerry Nelson visited OCIW on 7/22, reviewed the space frame and monocoque structure concepts, and recommended that the space frame design be carried to the same level of modeling as the monocoque. Finite element modeling of one of the space frame designs started in July and will be completed in August. 5) Slit masks and fabrication The Gemini Multi-Object Spectrograph (GMOS) project has ordered a $150K, laser-based mask cutting system from Advanced Recording Technologies (ART) in San Diego. GMOS will be using carbon-fiber composite masks produced by Kinetic Composites (KC), also in San Diego. The carbon fiber material has a very low coefficient of thermal expansion (maintains image scale with temperature changes), and has a specific stiffness 6 times higher than steel. A specification for the IMACS slit masks was written and sent to ART on 7/27. ART and KC will be providing quotations for mask blanks and the mask cutter, hopefully in August. The GMOS laser cutter should be tested in August, and I expect to visit ART prior to shipment of the machine to Victoria. 6) Instrument model We will eventually produce a full-scale model of IMACS. I hope to have models of the instrument structure and optics started this month. A full scale plot of the IMACS optical system is on the wall outside of my office. 7) Schedule A detailed schedule for building IMACS was presented to the Magellan SAC and the LCO operations committee in July. The schedule is clearly ambitious, but provides a roadmap for completing IMACS in time for the first instrument commissioning slot on Magellan I. The schedule will be distributed to the project team this month. Let me know if you would like a copy. 8) Electronics No specific progress in electronics for IMACS this month. However, electronics for Eric's IR project are making great progress, and will probably serve as the model for IMACS. 9) Software Christoph Birk reports that a simple GUI and camera simulator are now running. He has started working with the Nyden (MAC300) motor controller (which supports stepper and servo motors) for Eric's camera. This will be of use if we decide to use the same motor controllers for IMACS. Each controller may be daisy-chained up to 16 units, and can handle up to 4 motors or ADCs or digital I/O modules. 10) Guiders and CCDs Via Greg Burley: Here's the latest progress on the guider camera (for July): 1 - circuit board design was completed for the four basic boards (dsp timing, signal processing, clock driver, and power pcbs). Matrix Circuits is making one prototype panel (with 12 each of the four different pcbs). We expect to have the boards Aug 1st or so. 2 - Charlie completed the mechanical design of the housing for the prototype, which is currently being made by the shop. The active optical area of the CCD is centered on the faceplate. The dimensions for the guider box are 3.5 x 3.75 x 6 inches. 3 - all the parts were ordered and have begun arriving. Kudos to Jeanette for dealing with the big stack of requisitions, and for placing all those small quantity orders which the distributors seem to dislike. The longest lead time items are two thermo-electric coolers (12 weeks). 4 - circuit board design was completed for the CCD header board and for the backplane board. These will be submitted to Matrix Circuits before the end of July, with two week delivery. 5 - I'm currently working on a revised version of the guider camera documentation, but it probably won't be finished by the end of July. On the mosaic, I've started drawing up the schematics (which are looking a lot like the guider camera electronics). I'm working on a draft version of the documentation for this as well. 11) Optics ------------------------------------------------------------------- Optical Report for July, 1998 Tasks Scheduled for July: DONE A) Finish Ohara glass order DONE B) Checking which elements are best for focus/flexure control DONE C) Corning Fused Silica RFQ D) Write up complete profilometer proposal E) Prepare for grating, grism order F) Start preparing for thermal analysis ------------------------------------------------------------------- Tasks Scheduled for August: A) Write up complete profilometer proposal B) Prepare for grating, grism order C) Start preparing for thermal analysis D) Preliminary design of TV systems E) Order short camera material? F) Order Fused Silica ------------------------------------------------------------------- Work Completed: 1) Ohara Glass RFQ The glass RFQ was submitted to Ohara. The response was, for two sets of blanks each: Collimator $ 21.0 K Long Camera $ 42.3 K Short Camera $125.2 K One element in each of the long camera and collimator seemed to be under-priced by a factor of two, and one element in the short camera seemed to be overpriced by a factor of 6 (compared to recent orders). I asked for confirmation from Ohara on these prices, since maintaining a pleasant, long term working relationship with Ohara (the only manufacturer of decent optical glass), is paramount. The two under-priced elements remained to same, while the overpriced element dropped by $10K a piece. The short camera glass is therefore closer to $105K. Two sets of glass for the collimator and long camera have been ordered. 2) Corning Fused Silica RFQ The RFQ for the field lens was submitted to Corning. The bid came in high, and so a uniform RFQ was re-submitted to Corning, Dynasil, and Heraeus Amersil. Dynasil bid lower (by a factor of over 4). Heraeus is interested in bidding on finished lenses. 3) Flexure control A magic spot was found to be at 20 mm on the spectrograph side of the telescope focal surface. If the entire spectrograph aft of the field lens rotates about this magic point, then no image motions occur. In other words, rotation of the collimator (without the field lens) about this point results in deflection of the collimated beams by the same rotation. Brian Sutin 7/30/98 -------------------------------------------------------------------