IMACS progress report no. 49 B. Bigelow 10 May 2002 I) Project Status Currently scheduled tasks: Status: a) DSS redesign (Hare) IP b) DSS drafting (Cleary) IP c) DSS fabrication (Kowal, Castillo) IP d) Calibration system mech. des. (Hare) IP e) Long camera opto-mech assembly (Bigelow) done f) Field lens integration & assy (Hare) done g) Principal Guider Camera testing IP h) Shack-Hartmann Guider Camera testing IP i) Science Array controller fab (Burley) 95% compl. j) CCD array assembly (Thompson/Burley) on sched. k) Filter procurement (Sutin) IP l) Grism procurement (Sutin) IP m) Instrument electronics assembly (Bagish) on sched. n) MC fab. (Asa) done o) Control software design (Birk) on sched. p) Instrument enclosures design (Gunnels) on sched. Project events in April: - Mask cutting laser delivered to LCO - Long camera optical mounting completed, camera mounted in instrument (5/13/02) Latest project images: Final Assy: http://www.ociw.edu/instrumentation/imacs/devel/final/index.html Laser: http://www.ociw.edu/instrumentation/imacs/devel/laser/index.html Collim. assy: http://www.ociw.edu/instrumentation/imacs/devel/coll/index.html Electronics: http://www.ociw.edu/instrumentation/imacs/devel/electronics/index.html II) Optics (Sutin) 1) TORC is still working on S07. S04 will be returned to TORC after coating, so they can check the effects of some surface irregularities on the oil-coupled side after the coating is finished. 2) Tinsley is about five or six weeks behind, according the their latest schedule. I will be visiting this week, and get more details. 3) STF has S02, S03, S04, S09, and the short camera dummy filter. The are making the tooling now. We will get proposed curves when STF does the first test runs. We do have a curve for the 600 grism, which is very pretty. Coating test samples have been ordered for the grism materials. 4) The 600 l/mm grism substrate fabrication has been let to Harold Johnson. Several other companies no-bid. The material should ship today (5/8). 5) Barr: delayed R filters until 5/17. 6) Are we ordering Sloan filters at $27K? Custom Scientific was not cheaper, but they will come down if we make an offer. Are we making an offer? 7) Schott has not responded to a second letter. 8) Denton coated the enhanced Aluminum fold mirror, and it has arrived at OCIW. I purchased another blank from Custom Sci, which has been shipped to Denton for Enhanced Silver. 9) Filter boxes are ready for mounted filters, but someone needs to decide how the filter frames will be labeled (and do so). 10) Ohara 200 l/mm grism blank arrived too thin. Ordered a new one, which is supposed to arrive 2002-05-15. 11) 300 l/mm glass arrived. I intend to send an RFQ to HJOL for fabrication. Reply is expected this week. 12) Optics are here for double-pass testing if we want to do that. The setup is downstairs on the optical bench, and has been tested on a 3" spherical mirror. I need to know the height of the optical axis for the IMACS optics when they are on a stand. 13) STF does not have test samples for the previous coatings. I need to find someone who can scan the plots and fit the data. 14) Echellette: waiting on Bruce for envelope. 15) Modeling of instrument for slit mask cutting not started: deadline 2002-05-24. 16) I sent all the TORC short camera data I have to Harland to play with. He thinks he can improve the camera a bit. No reply as yet. III) Electronics (Bagish) - Motion Control Electronics Chassis #4 complete. - Rebuilt & modified power supply. - Mycom Indexers jumpered to provide differential clocks to stepper drivers. Modified all spare indexers. - Re-fitted chassis into Rack #1 for better ergonomic placement. - Schematics continue to be updated with corrections and fixes. To do in May: - IMACS Bulkhead design. - Add front panel over-ride switches to 4 chassis'. - Retro-fit Chassis 1 & 2 with hard-stop logic. IV) Software (Birk/Clardy) Birk: - PR-/SH-guider theta motion: We measured a displacement of about 850 um rotating the SH-guider 180 degrees. That means we need an active control loop for both theta-motions. Additionally Tyson will replace the chain with a bigger one. In May I hope to conduct extensive tests with the guiders while they are mounted on the rotating IMACS structure. - Structure rotator: I have written a test-GUI that allows to rotate the IMACS structure. Alan and I plan to test it in early May. - Disperser server: I have written the test-GUI for the disperser server (5 axis: wheel, 3 grism-tilts and the clamp-mechanism). Whenever the mechanics becomes available I am ready to test it. - Science Array software: No progress this month. Ian and Greg hope to have a readout-test setup ready later in May. I am ready to test my software doing full-array and sub-raster readouts. Clardy: Mask generation software was enhanced by writing a task to create a PostScript plot file for the mask with each slit labeled by its object name. This is done for both IMACS and LDSS masks. A program was written for Brian to create a mask for the center field guider, to be cut by the laser machine. This and the general field mask cutting will need updating with the final cutting parameters which will be found when the machine is actually installed on the mountain. I hope to hear from those doing the installation when such values are known. The generalized optics code should be installed in the mask generation software soon, and will be able to use the actual design values provided by Brian. Changes to these values will involve only editing the Optical Specification file, and not any compilation of the code. A general algorithm for the automatic computation of slit lengths after resolving conflicts has been created. It requires the computation of detector space conflicts in terms of focal plane slit positions, and this computation is not yet defined as it would involve the inverse of the optical transform computation. However, I believe an acceptable approximation can be formulated. Work is also underway on formulating an interface GUI program to allow observers to more easily input the needed data for mask generation, and to test that data for internal consistency. Some consultation with the astronomers on their preferred user interface will be necessary. V) Detector Systems (Thomson/Burley) For much of the past month, we have been doing cooling tests on the dewars and attempting to tune the cooling straps which attach the cold surface to the ccds. For IMACS, the cool-down time to -100 C (without ccds) is about 200 minutes for the chips closest to the cryotigers, and 300 minutes for the chips furthest from the cryotigers. The far chips settle to -108 C, while the near chips settle to -115 C. The heater resistors (one per chip) are able to bring the chip temp up to -90 C, as well as providing some interesting heat cross-talk through the platten. We have tested the electronics with all boards in place. The dsp can read/write to each board, confirming that the backplane and addressing-decoding scheme work. VI) Mechanics (Bigelow/Hare) Bigelow: In April: 1) Final assembly and spacing measurements for the long camera completed, and the triplet spacer needs to be replaced with a 0.5mm thicker version. 2) Main optics (field lens, collimator, lcam) all installed on instrument. 3) Final assembly and alignment of SMS on structure delayed to May. 4) Preliminary design of cable wrap and instrument enclosure details (instrument dark slide) done, uses Da-Lite movie screen. 5) Design and fab of dewar dummy mass for flexure testing cameras completed. 6) Design and fab CCD array dummy mass for flexure testing dewar completed 7) SMS mount design revised to clear instrument housing. 8) Imaging mirror potting started - will finish in May. 9) Slit mask fab tooling for LDSS2 masks designed and fabricated. 10) Presented IMACS update for April SAC meeting in Pasadena. 11) Ordered and installed new hoist for trolley crane in assembly area. 12) Ordered ventilation fan and ducting for laser room at LCO. 13) Ordered disc wiper parts for structure carriage from Rettig. 14) First 100 slit masks delivered to SBS from California Hydroforming. In May: 1) Achieve first light through optics (field lens, collimator, imaging mirror, long camera). 2) Commission mask laser at LCO. 3) Finalize instrument hatch design. 4) Start fabrication of slit mask carriers (for use at LCO) and order parts. 5) Start design of second (removable) imaging mirror for silver coated mirror. Hare: Current Work * Revising drive mechanism on Principle and Shack-Hartmann guide cameras to resolve flexure issues. * Continued opto-mechanical and electro-mechanical assembly and testing of the Principle and Shack-Hartmann Guide Cameras. * Field Lens has been mounted in its cell. * Design of Taper Pin Assembly Tooling complete and ready for drafting. * Assembling one Grating Tilt Mechanism underway. * Assembly tooling for mounting a grating to the flexure is complete and awaiting drafting. Future Work * Continue assembly, testing, and rework of all guide cameras as necessary. * Mount the Field Lens onto the structure. * Revise Clamping Assembly to resolve alignment and operating issues. * Revise and fabricate DSS Drive Assembly * Assembly and testing of the Disperser Server System. * Fabrication of the second shutter. * Resume design work of the Calibration Unit. VII) Fabrication (Kowal) April's Report: 1) Dewar front plate and clamps are done. 2) Tapered guide camera bases are 95% complete. 3) Electronic plates and brackets were made for Joe. 4) Covers were made for the field lens & collimator. 5) G.T.M. base plates were modified 6) Encoder brackets and more modifications to the G.T.M. are in progress now. Expectations for May: 1) Completion of G.T.M. mods 2) EFT Base 3) Four wiper assemblies (Rick) 4) Modify filter server bases 5) Complete repair of G.T.M. Trunion. 6) Steel base for CFG. VIII) Other Business Next meeting: 10:15, 6/4/02 (Note it is on Tuesday!)