IMACS progress report no. 9 B. Bigelow 8 January 1999 Engineering Objectives for December: Status: Done A. Finish solid model of SHM (Bruce) I.P. B. Finish solid models of TV guiders (Tim) I.P. C. Finish prelim. design of DS (Tim) I.P. D. Start prelim. design of L. Cam and Collim. optics (Tim) I.P. E. Identify/Contact consultants regarding TV guiders and Opto-mechanics Done F. Start prelim. electronics concept design (Carr/Bigelow) Done G. Start prelim. software concept design (Birk/Bigelow) Engineering Objectives for January: A. Complete DS preliminary design (TB) B. Complete guider optical layout and start mechanical layout (TB/BS) C. Review Schier's camera and collimator proposals (TB) D. Complete structure and test/install pallet prelim design (BB) E. Review electronics prelim design, start Eng/Tech search(?) (BB) F. Review software prelim design (BB) G. Start schedule/budget revisions for PDR (BB) Optics and CCD reports from Brian Sutin and Greg Burley attached. 1) Project scope, budget, and schedule Invitations for reviewers for the IMACS Preliminary Design Review (PDR) went out in the beginning of January. The review is currently planned for the end of March, and will include optical, mechanical, electrical, and software design, as well as project budget and schedule. 2) Conceptual designs A meeting with Alan Schier was held at the end of December. Alan will be providing estimates in January for mechanical design of the long camera barrel, the collimator barrel, and shutters for both cameras. Alan has recently completed camera barrel designs for similar Epps cameras in Keck/DEIMOS and Keck/ESI. Tim is working on design of the disperser server system. This work is a taking longer than estimated, but is making good progress. There are preliminary designs for the grating cells, and space envelopes established for the grisms and the disperser wheel. Tim is looking into commercial indexing rings for accurate repositioning of grating cells. A final concept for the disperser server stage (wheel or linear motion stage) will be completed this month. Preliminary design of the guider camera stages has not started as scheduled. Sutin is looking into the possibility of moving the guider fields to areas outside of the nominal 30 arcmin FOV. Such a move would avoid any vignetting of science fields by the guiders, but may be precluded by vignetting by the telescope. Bruce is working on instrument structures. The instrument structure, test/installation pallet, and housing were originally planned to be contracted out, but we are now planning to keep the structure design in-house. Progress has been made on the main truss, main optical support structure (MOSS), slit area support structure (SASS), and camera trusses. Gerry Luppino is working on preliminary design of the IMACS dewar. He is currently commissioning the UH 12K x 8K mosaic camera, but reports that he is making progress on the CCD sub-package design for IMACS. He is also learning Mechanical Desktop 3, the same design program Bruce and Tim are using for IMACS. Use of the same program will simplify adding Gerry's design work into our IMACS models. In general, we expect to have all the preliminary mechanical design ready for the review in March. 3) Electronics A meeting was held with Dave Carr (Magellan Project) to begin the electrical/electronic design for IMACS. Dave has started schematics for all of the IMACS motion stages, and will be providing lists of standard Magellan components for use in IMACS (motors, limit switches, stepper drivers, etc). Dave will help us find an electronics engineer/technician once the electronics design tasks have been well defined. 4) Software A meeting was held with Christoph Birk (OCIW) to discuss preliminary design of the software component of IMACS. Christoph is also developing software for OCIW IR instruments, and expects to adapt much of the IMACS software from existing work. 5) Optics Via Brian Sutin: DONE, December: 1) The Ohara glass blanks for the collimator have been measured, weighed, and shipped to TORC for fabrication. The Dynasil Fused Silica collimator element was also shipped. 2) The long camera direct-imaging mirror blank has been ordered from Corning. Corning ULE was cheaper than Schott Zerodur or Ohara E6. 3) Harland Epps has provided the melt calculation and final tune-up for the collimator. 4) The Canon lens principle planes have been measured. All the information for the final TV camera layout now exists. 5) I have all of the DEIMOS filter history from Dave Koo, but have not yet looked at it. ------------------------------------------------------------------- TODO, January: 1) Re-Check melt sheet update, just to satisfy paranoia. 2) Finish thermal analysis for collimator and short camera. 3) Ask coating companies for detailed proposals. 4) Assuming delivery of all glass, measure and ship blanks to TORC. Also do melt sheet update. 5) Start thinking about filters. Coming up: 1) Get cost estimate and drawing for 6.5" etalon from Queensgate. 2) Calculate image motion sensitivities. 3) Calculate alignment sensitives. 6) Guiders and CCDs Via Greg Burley: Guider camera update for December: 1 - testing of the circuit boards continues. Solved an initialization problem, where the DSP would power up but not execute any code. The problem was a combination of burning a couple of EEPROMs incorrectly (ie really burning them), and a small change in the DSP bootstrap algorithm which I hadn't noticed, and the bootstrap software didn't expect. The DSP now powers up, happily loads code from the on-board EEPROM, and talks to either a sparc or linux host over the RS-232 link. 2- testing of the add-on hardware for PCI board continues. 3 - started an html version of the guider camera design document. The link to the web pages should be available (soon) at http://www.ociw.edu/~burley/ccd/guider.html Mosaic camera update for December: 1 - the temperature probe arrived, paving the way for further testing of the cryotiger. 2 - the rep for Keyence came in to demo their confocal microscope + laser displacement sensor. The displacement sensor had no problem "seeing" the anti-reflection coated surface of the SITe chip. It easily detected the beveled edge of the chip, and the aluminum trace at the edge of the chip (which was only 2--3um high). Spec-wise, it should measure with 0.2um resolution using a 7um spot size, at a stand-off distance of 30+/-1 mm. The stand-off distance should be enough for us to measure the array through the dewar window. The cost is about $20K (ouch)! There is a $5K displacement sensor (sans microscope) in the Keyence line-up which may do the job, when teamed-up with a regular high powered microscope. Spec-wise, it can measure with 1 um resolution using a 30um spot, at a stand-off distance of 30+/-5 mm. We will be looking into this one -- it looks to be a better unit than the one used at NOAO to measure their mosaic. 3 - updated the design for the fiber interface to get rid of the byte- serializer and decoder chips, which might have loss-of-signal/re- synchronization problems. The new serial link design is somewhat simpler parts-wise, but now uses two duplex optical modules (ie two fiber pairs) rather than one.