IMACS progress report no. 54 B. Bigelow 3 October 2002 I) Project Status Currently scheduled tasks: Status: a) DSS drive design (Hare) Done b) DSS drafting (Cleary) Done c) DSS assembly/testing (Hare, Kowal, Castillo) IP d) DSS Grating Tilt Mech testing (Hare) IP e) Calibration system mech. des. (Hare) on hold f) CCD array assembly (Thompson/Burley) IP g) Grism procurement (Sutin) IP h) Grism cell design (Bigelow) Done i) Grism cell drafting (Cleary) IP j) Entrance hatch design (Bigelow) Done k) Entrance hatch drafting (Cleary) Done l) Entrance hatch fabrication (Kowal) ready to start m) Short Camera shutter fabrication (Kowal) Done n) Short Camera shutter assembly (Hare) ready to start o) Instrument electronics assembly (Bagish) on sched. p) Control software design (Birk) on sched. q) Short Camera opto-assembly (Bigelow) IP r) Instrument enclosures fab (Gunnels/Paragon) Done s) Instrument enclosures installation (Gunnels) IP t) Instrument utility wrap fabrication (Rettig) IP u) IFU design and build (U. Durham) IP Project events in September: - First CCD array assembly with all 8 chips - First spectra with grating, detectors, long camera, and software - Short camera aspheres approaching completion Latest project images: Final Assy: http://www.ociw.edu/instrumentation/imacs/devel/final/index.html Dewar Assy: http://www.ociw.edu/instrumentation/imacs/devel/dewar/index.html Enclosures: http://www.ociw.edu/instrumentation/imacs/devel/enclosures/index.html II) Optics (Sutin) * The filters are all mounted in their respective labeled frames by their corners except for the long camera spectrographic dummy filter, which is still inside the long camera. They need to be RTV'ed in. * Tinsley has finished S08, and probably finished S01. We await final S01 data. We hope to sign off later this week. * The S04 replacement is still at TORC, just going into polish. Should be finished in 3-4 weeks. * 300 l/mm grism is at ThermoRGL, having the ruling applied. While there, the coating was damaged, probably from no fault of their own, but because the coating failed the "scotch tape test", or came off of the surface too easily. The coating needs to be polished off. * 600 l/mm grism glass is coated and at HJOL, having the two parts cemented together. The original choice of cement was too viscous and dried to fast for a part this large, so we have switched to a different cement. * The echellette grating has been requisitioned. The prism detail design has not been started. * The 200-micron pinhole for making S-H calibration frames is here. III) Electronics (Bagish) In September: - Chassis 2 upgraded with Altera hardstop logic. All chassis upgrades are complete. - Set up 20 RTD thermal elements for test. Tested o.k. - All MCS panels have been surfaced and anodized. Four panels are at the engravers. - Eight cables assembled. 70% completion. - Installed Disperser Server Tilt A micro-stepping driver. - Fluid/Air pressure/temperature sensors came in. For October: - Attach instrument end manifold and wire up individual subsections. - Engrave remaining panels. - When installed, measure length of cable wrap and complete assembly of remaining ends of wrap cables. - Cable assembly to 90% completion. IV) Software (Birk/Clardy) Birk: - Gratings/Disperser Wheel: No progress (under construction) For October I plan to continue testing of the grating mechanism (ie. control-loop) and start testing the disperser wheel. - SH-, PR- and CF-Guiders: Conducted flexure tests with AlanD and Tyson. I tested and fine-tuned the control loops for the theta axis of the PR- and SH-guiders. Improved resolution for the theta drive(s): The ratio of the current system is 1.3 encoder-steps per motor-step. Ie. increasing the encoder resolution (from 5um to 1 um) requires a change of the motor-gear(s). - DSP/Science Array Software First data acquisition using the IMACS software suite (CCDServer, CamGUI and QlTool) reading one chip at a time. - HP-Sensor Unit Final test of 20 temperature sensors was successful. All sensors are within +-0.06 deg. Celsius. - 2nd shutter no progress (not assembled) - Mask Server For October I plan to test the new version with 8 masks (was 6). Clardy: - Got the changes to GMAP made by Skip merged with those made to support IMACS guider fields. Verified that features of all these changes are working. - Looked into changing how the stars are selected for the high density USNO-A catalog. There is a great difference in different parts of the sky in star density, so one magnitude limit based on the average density does not always work, and can suppress the plotting of suitable guide stars in sparse areas. - I made an interactive program to test the optics transform polynomials supplied by Brian. The optics code will be needed in the GMAP program because the guide stars are significantly displaced from a linear approximation when we have a guider field 15 arc minutes off axis. - I am starting to outline the operation and appearance of the Astronomer's GUI, which will be a purpose-built editor for the mask generation program's observation file. It will present choices and defaults, and check input for consistency. V) Detector Systems (Thomson/Burley) (Bigelow reporting) In Oct: 1) Getting the fiber link to work (prereq for the 8-chip readout) 2) Get all detectors working together in dewar 3) Burley in Pasadena: 10/1 - 10/12 VI) Mechanics (Bigelow/Hare) Bigelow: In Sept: 1) Continued short camera assembly 2) Finished instrument hatch/calibration screen design, drafting done 3) Finished grism cell designs, drafting started In Oct: 1) Continue short camera opto-assembly 2) Alignment and testing of slit mask stability 3) Grism cell fab drawings to shop 4) Order final cryotiger hose assemblies for both cameras 5) Finish plumbing design for guider cameras 6) Return flexure control stage to PI for extended cables and re-calibration 7) Progress revised grating cell and tilt mechanism designs Hare: Current Work * Continued opto-mechanical and electro-mechanical assembly and testing of all Guide Cameras. * Designing counterbalance for the Shack-Hartmann Guide Camera. * Assembly and testing of the Grating Tilt Mechanism. Investigating flexure issues. * Ordered parts for the DSS Drive Assembly and Cable Wrap. * Fabrication DSS Drive Assembly. Future Work * Continue assembly, testing, and rework of all guide cameras as necessary. * Continued testing of the Grating Tilt Mechanism. * Assembly and testing of the DSS Drive Assembly. * Assembly and testing of the Cable Wrap Subassembly. * Assembly of the second shutter. * Resume design work of the Calibration Unit. VII) Fabrication (Kowal) In September: 1) Shutter v2.0 is back from being teflon anodized. 2) Machined 6 new pillars for the G.T.M. 3) Four stainless steel G.T.M. base plates have been finished. 4) Made new titanium brace for G.T.M. Trunion. 5) Started machining Carousel Drive Base. Expectations for October: 1) Finish Carousel Drive Assembly 2) Finish Hatch 3) Finish remainder of new Imaging Mirror Cell. 4) Start Machining Grism Cells. VIII) IFU Optics: - AOA microlens arrays arrived and tested thoroughly: Input arrays: - Back focal length: Mean value 18.5 microns - Pitch: 402.375 microns (goal 402.5 microns - acceptable) - 15.75 out of 1320 lenses wrong, mostly at edge where not used. - Very smooth and clean surfaces, well defined diff-limited foci Output arrays: - Back focal length: 178 +/- 15 microns mean value (acceptable) - Pitch: 244.957 +/- 0.039 microns (acceptable) - Faulty lenslet statistics: 5 % of lenses show strong damages. There are scratchy, rough surfaces on many surfaces: Coverage 1/2 to 1 lens: 14 % Coverage 1/4 to 1/2 lens: 28 % Coverage 1/8 to 1/4 lens: 17 % Coverage < 1/8 lens: 43 % - The arrays are badly positioned on the substrates, some inclined and all in a position wrong by 5 mm. - About half the batch is quite dusty. The decision is to reject the whole output array batch. This will result in a delay estimated to be 6 weeks for re-manufacturing. Even when the errors were accepted the misreading of our drawing results in difficulties to get the lenslet arrays mounted. - Fiber bundles arrived at Durham. Pitch was measured to 244.1 microns (goal 244.3), which is acceptable. Mechanics: - Base plate two (final version), comb and auxiliary parts anodized. - V-rails hard anodized. - Fiber glass housing: Delayed. Company damaged perform and has to rework it. It is planned to visit the company soon to assure that they can overcome this problems. - Completion of volume dummy is still expected after delivery of the fiber glass housing. Procurement: Micro lens coating delayed by output array acceptance problem. Integration and Test: - Alignment document preparation is going on. - Micro lens test setup works sufficiently. Additionally, some PSF measurements of the poor output arrays are made with high dynamic range to monitor the consequences on performance. Furthermore a white light interferometer will be used to quantify the surface roughness achieved. - Large alignment and assembly jig is finished. Hence, all but some minor parts for alignment and installation are ready. IX) Other Business Next meeting: 10 AM, 11/6/02