DEIMOS MEETING NOTES Tuesday November 8, 1994 NS-143 10:00 am Present: Bill Shepard, Neal Jern, Sandy Faber, David Hilyard, Marlene Couture, Deanne Lago, David Cowley, Jack Osborne, Steve Allen, Richard Stover, Bob Kibrick, Scott Trager. Status Of PDR Report The chapters getting substantial updates are Chapter 2, Optics (Harland is providing a lot more spot diagrams and pertinent numbers as needed); Chapter 5, Section 5.25 Error Budget for Slit Mask; Chapter 7, Flexure Compensation. The report will be going to printing services on Wednesday (November 9) afternoon and will return on Monday morning (November 14). We will be printing at least 100 copies. PDR Meeting The first rehearsal for the PDR will be held on Thursday, November 10 at 1:30 (place TBD). The second half of the dry run will be held on Friday morning, November 11 in NS-143. The dry run will follow the agenda (which will be updated today). Each presentation should contain the important facts that we want these people to know in order to make an informed judgement for us. Each individual presentation time allocation allows approximately 10 minutes for questions and answers. A packet of view graphs will also be presented to all in attendance along with their report. FIVE POINT IDEAS Chapter 1 - Sandy Faber 1. Link the scientific goals to the optical and mechanical design. 2. Present a list of goals that we want to achieve with the instrument. 3. Show them a picture of where the components are on the instrument. 4. Concluding point is a list of questions that are critical (at the moment) that we are seeking guidance on. · Why do the committee members think there is a flat fielding problem in CCD's? How can we flat field better? How can we test to determine the cause? · How do we obtain a rigid structure? What elements of the structural analysis that might be causing us problems have not been adequately thought out? · Rigidity of the focal plane? Internal buttressing design for the part of the spectrograph that will hold the cameras? What is the effect of cantilevering out of the structure (in front) which is fairly weighty and how will it talk to the components inside during rotation? These items have not been designed yet, so we are just asking advise about them from the com- mittee with their great wealth of knowledge. We need to know as closely as possible the toler- ances we need to design to as soon as possible. · Why do we have a flat fielding problem? · Why do CCD's fringe? · Structural guidance? · CCD procurement plan comments? · Observers point of view comments (what modes have we left out)? · Scheme for constructing and aligning the CCD mosaic? We are relying on the committee to raise flags on some items, but not necessarily provide the solu- tions. Chapter 2 - Harland Epps Harland was not at the meeting to go over his talk. Chapter 3 & 4 - Richard Stover 1. Review the science requirements of instrument including 8k x 8k mosaic size. 2. We are attempting to take multiple approaches to acquire these CCD's. They don't exist in the form we need them at this time. 3. We are mounting a major in house effort to do the CCD thinning, explaining what we are doing on this subject and what our status is to date. 4. We are attempting to develop various CCD innovations which will help us to meet some of the science goals of the instrument as far as foundry CCD production. 5. The budget is to tight regarding CCD's. We need to include the mechanical components regarding Detectors and CCD mosaics at this time. A description of the device that holds the CCD's needs to be given. The warm/cold adjust- ment phase and it's philosophy needs to also be discussed. Chapter 5 & 6 - Dave Cowley 1. This instrument weight is approximately 7,000 to 8,000 pounds and it sits on the Nasmyth platform of the telescope and rotates in the opposite direction. Structural stiffness will be discussed including the tolerances which are in relation to the budget. 2. We need to deliver a reliable instrument because fabrication is taking place in California and it will be hard to fix large problems budgetary wise once the instrument is in Hawaii. (HIRES is one of the most reliable instruments that Keck has received to date, and was fab- ricated her e at Lick.) 3. Slit Mask handling system has to be a very accurate placement device and extremely reli- able, as it will be operated by essentially untrained operators. 4. For the flexure control system, we prefer a two axis system. Chapter 7 - Garth Illingworth Garth was not at the meeting to go over his talk. Chapter 8 - Bill Shepard/Richard Stover 1. Requirements and how they are met, including the outline of the tasks we are dealing with in the basic system and the handler & cutter (including the extreme tolerance threshold given to vendors). 2. Background information on the laser technology that is available to achieve our goal requirements. 3. Laser safety, including training and maintenance. 4. Software interfacing, including types of data that the system would deal with (the laser cut- ter) and identifying and archiving each slit. 5. Commercial options regarding the vendors available and who we have contacted to date. The group from Hawaii at the PDR will want to get a sense of what it looks like, how dangerous it is, how much training will be involved, and the costs of operation. 1. There will be 16 channels per CCD mosaic with a goal of 100,000 pixels per channel read- out. 2. Second generation Leach controller is the default controller system with the first generation Leach system as our fall back. 3. Each dewar will have an independent controller system which will allow the two sides of the spectrograph to be operated independently. 4. The Leach controller will support a variety of readout modes. 5. Justification for not switching from a Leach system to another type. Chapter 9 - Steve Allen 1. The critical design review for the software is still six months away. Given the great deal of variation in the design of the hardware and optical needs, it has not been reasonable to invest a lot of time into the design of software control devices at this time. 2. The user interfaces and instrument control software will be based on the same model as HIRES, which has been quite successful. There will be a keyword based language which will allow for scripting in batch mode operations, and a graphical user interface for observ- ers to keep an eye on all components of the system at once and know where everything is, (which will be able to be used simultaneously from multiple locations). 3. The major portions of the spectrograph control software will be nearly identical to HIRES (Galil motor controllers, hatches, brakes etc.). 4. The largest challenges for the control software are the slit mask changer, it's alignment mechanism, the laser cutting system and the micro-positioning actuators needed for the flex- ure control system. These are items that we have no prior knowledge/experience with. 5. Image acquisition display and quick look analysis of images as large as this. We can talk of the areas we have planned for research between the PDR and the software review. Chapter 10 - Dave Cowley 1. We are planning to complete the instrument in 1998 and are planning on completing two beams which is reflected in the schedule at this time. 2. The effort is primarily supplied by the Lick staff, we are not intending to rely on outside institutions. 3. We plan to put a lot of engineering resources into the project immediately following the PDR report. 4. The decision to fund the second beam is needed by mid 1995. The impact of not having that decision then is that we are beginning to build optics and there are some cost savings by building dual optics instead of one at a time for each element. 5. Our plan is to purchase the optical glass for three beams now, the money for one of the beams comes directly from the contingency fund. We plan to start optical fabrication as soon as we receive the glass. 6. We plan to design and build the slit mask handler in 1995 also. Chapter 11 - Dave Cowley 1. The budget as approved by the SSC in May of 1994 is for one beam. 2. The budget was divided into individual tasks with expected starting and ending dates and cost codes assigned to each of them for the purpose of project tracking. 3. Milestones have been established together with the tasks to help us in the tracking of the project time and budget. 4. The contingency is maintained as a separate fund and will be dispersed as required in a knowing and open way. We will include details regarding the contingency funds in our quarterly reports to the SSC. 5. In tracking the project, we will track manpower as hours rather than dollars and materials/ supplies as dollars. The whole thing will come together as dollars when we look at expendi- tures to date. List of Review Committee Chair - Dan Fabricant: He is with the Center for Astrophysics, Harvard Smithsonian and builds space instruments. He is a general all around instrumentalist who knows quite alot about optics and mechanical design. He currently runs teams as a Project Manager. Peter Gillingham: He is a mechanical engineer and is currently the Operations Director at Keck Observatory in Hawaii Harvey Richardson: He is an optician (an academic similar to Harland) at Dominion Astrophysi- cal Observatory in Victoria B.C. Jim Gunn: He is an instrumentalist, who leads the Sloan Digital Sky Survey Project for which he designed the optics, CCD electronics and most of the mechanical design. Steve Shectman: He is a staff member and instrument designer at Carnegie Observatories in Pas- adena and was a student of Jim Gunn's. Hilton Lewis: Is the Manager of the software group at CARA in Hawaii. Chris Stubbs: He has had great success with the MACHO project and is now with the University of Washington. Jim McCarthy: He is the top instrument person at Caltech and is currently working on building the blue arm of LRIS. John Geary: He is at Harvard and has been designing CCDs to be made at Loral. Frank Melsheimer: He runs DFM Engineering in Boulder Colorado building standard small tele- scopes. Seating Arrangements A table will be set up for the committee members and P.I.'s and another for presenters along the side near the accordion doors.