IMACS progress report no. 21 B. Bigelow 6 January 2000 1) Project Status Currently scheduled tasks: Status: a) Filter Server drafting started b) Long cam. prelim. mech. design (Bond) started c) Shutter drafting (Hare) finished d) Shutter fabrication (Kowal) late start e) Center Field Guider design (Hare) on schedule f) Collimator prelim. mech. design (Bigelow) finished g) Slit Mask Server drafting (Poteete) finished h) Slit Mask Server fab (Kowal) late start i) Slit mask development (Bigelow) late finish j) Dewar fab. (Luppino) on schedule k) CCD controller elec. design (Burley) on schedule l) Motion controller design (Carr) on schedule Details: a) FSS drafting is under way, following late finish of SMS drafting. b) Comparison of coll. and Lcam optomechanics in early January, leading to fabrication of prototype(s). d) Shutter fab on hold pending completion of FSS and SMS fabrication We will send this work out for fabrication if necessary i) Investigation of mask materials and coatings continues without schedule impact. l) A prototype of the instrument controller is being fabricated for the FSS. The hardware and firmware should be completed in Feb. Other project progress: New CNC vertical machining center: The VF4 is now operational. First parts of stainless, brass, and aluminum were completed in December. We have two new workstations now for Vince - tool boxes and counter space at the VF4, and a desk and computer in the IMACS assembly area. George Berger, a consulting electronics technician, has started work on the Filter Server controller prototype. Greg Bredthauer, previously a programmer with the Magellan project and now a grad student, started motion control software/firmware design for the FSS in December. Dave Carr is directing Greg's work. 2) Optics (Sutin) 2.1) The results of the SilverStar coating on a grating arrived from Spectronics. The results were highly negative. We will not be using SilverStar on the gratings. 2.2) The field lens from Contraves is finished. It should arrive in early January. 2.3) One CaF2 boule from Optovac for the Long Camera arrived at TORC. No sign so far of the second Long Camera boule. Optovac was just sold to Corning, but they expect business-as-usual. 2.4) Coherent has been asked to bid on the coatings for the Collimator and Long Camera. A phone estimate was 20% to 40% over budget, which earlier cost savings will offset. I believe that the coating designs should be able to give good performance over an extended wavelength range. 2.5) Another quart of Cargille coupling fluid was ordered, solely for the purpose of chemical and mechanical tests. 2.6) A construction model for the Short Camera has been decided upon. The design is athermal, so the scale will not change with temperature. This two-asphere design has performance superior to the previous three-asphere design, and one fewer element. TODO List: 1) Baffle analysis 2) More thorough sensitivity analysis 3) TV Camera designs 4) Filters 3) Electronics (Carr) No report this month. 4) Software No work scheduled for December. 5) Mechanics Tyson: 1. The camera shutter solid models are complete incorporating several changes suggested at the design review meeting held on November 29, 1999. 2. A 'draft' revision of the shutter drawing package was completed before the Christmas break. A 'for construction' set of drawings should be completed by January 7, 2000. 3. Part ordering will be finalized and submitted with completion of the shutter drawings. No excessive lead times for part delivery are expected. 4. Camera shutter manufacture could tentatively begin January 10, 2000. 5. Motion control and motor electronics issues are to be discussed with electronics and software engineering. 6. The IMACS File Server has arrived and will be setup upon selection of a suitable location. 7. A meeting is scheduled to take place today to discuss the scope, schedule, and preliminary design constraints, criteria, and requirements for the guide cameras. Tim: 1. Optical Error Budget / Sensitivity Analysis - was developed and refined. - several methods for adding the contributing errors were investigated. - results were established which give acceptable image degradation with reasonable tolerances assigned to each element. - further work needs to be done by Brian that will allow us to add errors in a more realistic way, and allow us to begin to try to offset some of the more significant errors. 2. Doublet / Triplet mounting scheme: - work was started on a scheme utilizing an elastomer layer inside of a metal sub-cell - results are to be compared to a scheme utilizing flexures 3. Filter Server Plumbing: - most of the parts for the pneumatics of the filter server have arrived. - one of the stages was completed (plumbing) in order to see how well the fittings worked. Bruce: 1. Preliminary designs and analyses were completed for flexure-based lens cell concepts for the collimator. A procedure was written for alignment and assembly of the collimator doublet. Finite element models of one lens/cell/adhesive unit were completed to determine flexures, stresses, and thermal performance of the assembled unit. The stresses and deflections were found to be well within specifications. 2. Drafting and checking of the Slit Mask Server design was completed in December. Most of the ordered parts are in house, material has been ordered, and the SMS drawing package is in the queue for fabrication by Vince. 3. Slit mask material research continues. A preliminary finding is that coating costs for stainless steel masks are comparable to the cost of material plus fabrication. This makes the finished cost of steel or stainless steel masks comparable to carbon-fiber composite masks. Gerry Luppino: December progress: - Camera back-plate is in hand. Vacuum parts have been mounted. - The Ti flexure is completed and out being electro-polished. Due here any day now. - The invar focal plane mount is being machined now and is due next week. - Focal plane supports are being made now. Once the two PI XY stage adapter pieces are completed, I expect to assemble the whole unit and we can test for flexure. The exact method we will use to measure the flexure is still TBD. In the coming weeks, I hope to: - complete the alignment jig - complete the Z-drive mechanism - the SS parts need to be finished and then e-beam welded to the bellows assy. 6) Detector Systems (Thompson/Burley) Detector systems progress (Dec 1999) ==================================== Guider cameras -------------- 6.1 - we've done a preliminary measurement of the read noise (ie non- optimized), and traced some pattern noise to the DC-DC converters. We'll be adding some additional filtering to the power board. With linear supplies, the read noise is about 7.5 e- and with the DC-DC converters the read noise is 10 e- (at around 5 us per pixel). 6.2 - housings for the guider cameras continue to be built in the shop Array cameras ------------- 6.3 - GB worked on shrinking the circuit board layouts to the smaller size (see last month). So far, the power pcb, sig_proc pcb, and clk_drv pcb are complete, and the dsp pcb is still being worked on. 7) Meeting notes from 1/06/2000: The reports given above were presented in the meeting. Action items from the meeting: a) Next meeting: 10:15 AM, Wednesday, 1/26/2000, new conference room. b) Bruce to get FSS electronics prototype finish date from Dave. c) Christoph to check with Dave regarding electronics hardware specs. and firmware progress by Bredthauer.