IMACS progress report no. 31 B. Bigelow 3 November 2000 1) Project Status Currently scheduled tasks: Status: a) Disperser server (DSS) design (Bond) 90% complete b) DSS drafting (Meyers) in progress c) DSS fabrication in progress d) Field lens mechanics (Hare) started e) Mask server integration (Asa) on sched. f) Coll. fabrication (Danco) late finish g) Long camera mech. design (Bigelow) late finish h) Dewar fab. (Luppino) finished, due 11/10 i) Science Array controller des (Burley) finished j) Science Array controller fab (Burley) 90% complete k) Motion control (MC) electr. design (Carr) due end of Nov. l) MC fab. (Asa) started m) Control software design (Birk) on sched. Project events: Latest construction images can be seen on the IMACS web site: http://www.ociw.edu/instrumentation/imacs New images this month: Dewar, Slit masks, Slit Mask Server Flexure and cooling testing of the IMACS dewar was completed successfully at the end of October. See the website for images. 2) Optics (Sutin) 2.1) Raytheon has more accurate information on our aspheric requirements, as well as more information about what kinds of contracts we might consider. The are supposed to get back to us Real Soon Now. 2.2) The center-field Shack-hartman guider mask is going to be either 12 arcsec (as large as possible) or half of that. We will make masks for both sizes, and choose later. The size largely depends on how bad the telescope performance gets when the primary is out of shape. 2.4) The Request for Proposals for filters will go out as soon as I get and idea of the red cutoff for Arlo Landolt's CCD I-filter. If I don't hear back from him soon, the RFP's will go out anyway. 2.5) We cancelled the order to Almaz for a backup CaF2 blank after the price went up 36% in three weeks. 2.6) Schott says that they have the material to make our S02 element. They have to check if the transmission is acceptable before they will quote. 2.7) Corning/Optovac sent TORC a test piece of CaF2 so that they could check if the quality was acceptable from the smaller 10.5" furnaces. TORC has decided that the quality is marginally acceptable. 2.8) L03 and L05 are still being worked at TORC. L03 is just about finished (about one day). These elements are taking longer because the quality of CaF2 is low, and pits fall out of the material during polishing. 2.9) Newport TFL has done one coating test run. It was pretty good for a first test run. They will do another in the next week. Optics TODO List: 1) Baffle analysis, baffle materials 3) Electronics (Carr) Preliminary schematics for control of the SMS were completed in October. Parts have been ordered, and final schematics for assembly will be completed in November. Schematics for control of the guide camera stages are started. 4) Software (Birk/Clardy) Birk: Filter-Server ------------- I tested the new valve a few hundred times and found no problem. I'll wait with a more thorough test until we have all filter frames in place. Guide Star Catalog ------------------ I used the USNO-A2.0 to compile a special guide star catalog for our needs: USNO-A2.0 USNO-A-OCIW bytes per entry: 12 8 lim. magnitude: 25.0 21.0 number of stars: 526,280,881 524,890,999 I size of catalog: 6.3 GBytes 4.2 GBytes index bandwidth 7.5deg/0.25h 0.5deg/0.05h ave. # stars/index: 238,000 3,000 (*) (*) This is the number of entries I have to read from disk for each request to the catalog. I searched the new catalog (USNO-A-OCIW) using our guider geometry for empty fields: Lim.mag. fields searched no guide-star found (%) 18.0 10643 57 0.54 18.5 10549 9 0.09 19.0 10193 2 0.02 IMACS-GUI --------- I started on designing a graphical display of the instrument status. This GUI will allow the user to see the current light path through the instrument and status of individual components (e.g filter, mask). 5) Mechanics (Bond/Hare/Bigelow/Luppino) Bond: The solid model for the Disperser Server system is almost complete. This includes the carousel mechanism, and the extension/retraction/clamping mechanism. I plan to review the model with Tyson, Bruce, Vince, and Alan this week, and then it should be ready to hand to Julie for drafting (pending any changes). The next week or so, I shall spend getting purchase orders together, and red lining drawings that I have already received back from Julie. Hare: Shutters: 1. The shutter has been disassembled and examined with no significant wear issues or problems to report. 2. Future work planned for the shutter includes anodizing shutter components, re-assembly, further operational tests, and continued software and electronics integration. IMACS Guide Cameras: 3. The solid models for all cameras, including the designs for mounting all optical elements for each camera, are completed. Revisions to the models continue to be made as needed. 4. The drawing packages for all guide cameras are near completion. These packages will be reviewed and red-lined as necessary. Manufacturing ready assembly drawings will be ready in the next several weeks. 5. Future guide camera work for the month of November includes completion of purchased parts ordering, and commencement of manufacturing of the three guide cameras. IMACS Field Lens: 6. Work on designing the mounting for the field lens has begun. Several lens mounting methods are being investigated, and FEA analysis will be completed for each. Bigelow: Slit Mask Server: SMS: The slit mask shuttle and transfer mechanisms were assembled together on an optical bench in October. Testing of the two mechanisms working together will proceed as soon as the control mechanics are completed, ideally by the end of November. Masks: Prototype slit masks were formed in October, with success for the aluminum and stainless steel materials, and failure with titanium. Additional prototypes in mild steel and brass are planned for November. Mask cutting: Another quote for a commercial laser cutting machine was received in October. At $280K, the cost substantially exceeds the budget amount. The quote will be reviewed with the intent to reduce the cost. Collimator: The collimator mechanics were due from Danco at the end of October, and are now late. The cell and barrel spacers are complete, and all the EDM work is complete for the cells. The barrel has only just been started. The mechanics are not yet holding up the assembly of the collimator, as the optics have yet to be coated. Long camera: Mechanical design of the long camera continued through October, and is now about two weeks behind schedule. Design of the lens cells and barrels are about 80% complete, and the design of the scale compensation system (flexures and actuators) is about 90% complete. Still remaining are the mounting details for the actuators, mountings for the shutter and filter server in the barrel, and alignment and assembly tooling for the entire camera. Dewar: Cooling and flexure testing of the completed dewar was carried out at the UH detector lab at the end of October. The flexure testing indicated that the focal plane is not currently balanced about the XY stage. Previous flexure testing showed maximum deflections of +/- 5 microns for a 180 degree rotation of the dewar, while results in the latest test were a factor of 3 times greater. The balance will be corrected during the final assembly of the dewar with the detectors and their packages. The cooling testing showed that the cryotigers can bring the focal plane down to -122C in about 4 hours, which is acceptable. Warming back to room temperature will take about 2 hours, for a total turn-around time of about 6 hours. The dewar is due at OCIW in mid November. For November: a) continue long camera design b) start fabrication of collimator alignment tooling c) progress slit mask fabrication development 6) Fabrication (Kowal/Storts) Kowal: a) Built fixtures for fabrication of disperser server parts 3233002, 3233002, and 3236001. b) Planned fabrication steps for DS 3236001 and 3231009. c) Currently finishing fabrication of titanium parts for grating cells. d) Modified purchased parts for short camera filter changer. 7) Detector Systems (Thompson/Burley) Array cameras -------------- 1 - lots of mechanical bits were fabricated in the shop this month, so we now have on hand the box for the 8k electronics, boxes for five sets of single/dual ccd electronics, four dewar heads + internal parts + side-plates, and 12 ccd boats. 2 - we power-on tested the electronic boards without burning up any parts. 3 - the next step is to have the dsp board link to the control computer. There is new EPLD code for the PCI interface, as well as the two EPLDs on the DSP board -- these need to be tested and debugged. Guider cameras -------------- 1 - the previous fixes to the serial link were not enough to fix the bit errors being seen at LCO. Two "fixed" PCI boards were sent down, but are not working. In the lab, the link works at 10 Mbps upstream and 20 Mbps downstream, without errors, over 120 m of CAT5 cable (the working link only needs to transmit 10 Mbps over 100m of cable). That is, the link is working reliably at twice the data rate that we require, and for 20% longer distance. I take this to indicate that we don't have a cable bandwidth problem, or an attenuation problem. At this point, it looks like an interference problem or a common- mode/grounding problem with the serial link transceivers (ie the signals are sent differentially, but they require that the ground at both ends be approx the same voltage). There is no way to reliably duplicate the LCO problem here in the lab -- at best, we can generate bit errors by switching on/off a bench-top fluorescent lamp plugged into the same power bar as the camera. The next step to make the link more robust is to switch transceivers to either RS-485 or logic drivers/optoisolators. The RS-485 solution looks to be more robust in the lab, but the lamp can still generate errors (although not as many). The parts for the logic/opto solution are not here yet. 8) Other Business Next meeting: 10:15, 11/29/00, new conf. room.