1. General Items:

Lens Element 1 of the camera has now been completed, and David Hilyard is currently working on the CaF₂ blank for Element 3. Element 1 has one of the largest departures from a sphere of any element fabricated at Lick and David Hilyard was able to a polish an excellent figure onto it. Details are in the optical section of this report.

George Laopodis is currently working on the rear side of Element 4. ORA is studying whether we need the front side of Element 4 as a pickup surface or if we can complete it beforehand.

A contract was negotiated with Coherent, Inc., for coating the camera elements including three CaF ₂ surfaces. The first set of elements will be transported to Coherent in mid-April. These include Elements 1, 2, 7, 8 and 9 of the camera and the dewar window. Coherent seems able to complete the coatings by our scheduled date of July 1.

The tests on the couplant fluids continue.

Fabrication of the parts for the camera barrel is in progress, with an expected completion date in June 1998 (now delayed to July 15).

Fabrication and testing of the grating system continues. The design of the flat mirror cell and carriage has been completed, and parts are being fabricated. Design of the cells and carriage for the 6x8 gratings is in progress.

The LN2 can is complete and has been cold tested. The parts for the detector housing have been fabricated, and testing is scheduled to begin in April (this has occurred).

Most of the parts for the rotational position-angle Renishaw encoder have been installed.

Wiring of DEIMOS is currently in progress. One of the motor control panels has been mounted on the instrument and will be permanently installed during the next quarter. The other panel is being completed and will also likely be mounted on the instrument next quarter.

An Orbit CCD has now been run in a dewar with the SDSU-2 system, and the design of all the Lick support boards has been confirmed. The Lick boards that will be used for the science controller and the FC controller, some of which require revision, have been ordered and are expected to arrive by the end of April. We are on track for having the science controller completed in June. Delivery of the Phase 3 Lincoln devices will be delayed one month owing to an accident that caused the loss of 12 wafers (72 devices). It was also found that many of the Phase 2 devices suffered from fatally low charge-transfer and high dark current and will be unusable. Lincoln is attempting to replace the devices voluntarily. Fortunately the back-up Orbit CCDs are proceeding well.

During this quarter, the majority of the software effort was directed toward ESI, but a considerable portion of that effort involves development of software that is shared with DEIMOS. The following items were successfully completed and tested during this quarter.
* Improvements to the figdisp real-time image display.
* Preliminary release of a graphical tool for display and analysis of engineering data.
* CCD controller software for reading out a 2Kx4K CCD using a second-generation SDSU CCD controller.

The Sun Ultraserver 450 computer (one of three donated to the DEEP/DEIMOS project by Sun Microsystems) that will be used at the DEIMOS instrument computer was received at UCSC in early January. That machine has been installed, configured, and is now being used for DEIMOS software development and testing.

2. Reports on Specific Areas:

2.1 Optics

The aspheric surface on Element 1 was finished in March. The OFFCTR was .0011", and the choppy after removal of the statistical noise was about 1.4, which was judged to be good enough. This surface with an aspheric departure of .047" (over 2000 waves) is the second most aspheric surface made at Lick (the most aspheric was .049"), but is twice as large and with a slope spec that is four times tighter than the most aspheric surface made here thus far. The completion of this surface completes all the aspheres in the DEIMOS camera. It is an important milestone.

We received the CaF₂ Element 3 from Optovac. Its diameter is approximately 13.5 inches, roughly 1 inch smaller than the design value owing to Optovac's inability to make the larger blank. The slight light loss amounts to only a few percent. The lens was beveled and fine ground on both sides. The first side is polished and the second side is being polished, with completion expected in early May (this has occurred).

The severe meniscus Element 4 was generated and fine ground on the concave (rear) side and is currently being polished. The front side of this lens is a prescribed pick-up surface. We may choose to adjust the radius of that side along with the rear of Element 6 to compensate for the increase in filter thickness from 6-mm to 9-mm since the initial design.

There are currently four surfaces left to finish in the DEIMOS camera. They are Element 3, one side; Element 4, two sides; and Element 6, one side. We expect to be finished with all but the pick-up surface on Element 6 by May 15 (it now appears that Elements 4 and 6 will be delayed until late June).

Reactivity tests of the five candidate optical couplant fluids with optical glasses, O-ring materials and RTV are in process. All but one O-ring material is reactive and have been eliminated (Viton is OK). Tests have started to assess the reactivity of mylar shim stock and vinyl bladder materials to these fluids.

2.2 Mechanical Design

DEWAR SYSTEM
The LN2 reservoir can is complete and has been leak and cold tested. With the cold finger in open air, it holds for over 36 hours. All the parts for the detector housing have been fabricated, and we are currently waiting for an O-ring to leak test it. The parts for the cold path have all been designed and are being fabricated.

A test mosaic of CCD packages was assembled and mounted in the detector housing to confirm that everything fits properly. We are planning several trial assemblies of dummy Orbit packages next quarter (this has occurred).

CABLE WRAP
The cable wrap as originally designed does not give enough rotations. A new design is pending. Since the number of cables has been reduced, it should be possible to use a smaller-size cable carrier, which should allow us to meet the 2-¹/₃ revolution specification. No impact on the schedule is anticipated.

GRATING SYSTEM
The grating slide system was balanced and can now be moved under manual control using an electric drill motor to turn the drive screw. The position 1 slider, the cable wrap slider, and the moveable slider (which simulates the missing sliders 2, 3 and 4) all moved smoothly, while the 200-pound counterweight moved in opposition. A few interference items were noted and corrected. The fixed counterweights on side B were installed, and the instrument was again balanced. At that point, grating work was stopped to run cables, mount electronic control boxes, and work on the cable wrap, band brake, and Renishaw encoder. Preliminary testing on the grating slide has started, and a web site was set up to announce the results and accept requests for new tests. This can be found at:
http://www.ucolick.org/~loen/Deimos/Tests/deimos_testing.html. Tests include:
* Measuring the travel limits to verify that all four positions will fit on the slide.
* Measuring the motor torque to see if the Galil 50 motor can drive the slide (at several position angles).
* Checking the ability of the remote clamping system to mount each grating repeatably to high positional accuracy at all position angles.

Design work underway includes finishing the flat mirror and the position 2 slider (this is now complete). The design of position 3 and 4 sliders (almost identical units) is more than 50% done. Limit switches are being installed, and chain guards are being designed to protect hands and fingers. The remote clamps for position 2 have been installed onto the fixed support structure. Testing awaits the fabrication of the position 2 slider.

The encoding design problem for position 3 was solved by the decision several months ago to eliminate the possibility of an 8 x 12 grating in this slot, and the Gurley encoder packages easily now. Electronic testing has shown that the Gurley electronics boxes can be moved up to 20 feet away from their encoders (instead of the manufacturer's limit of 48 inches), so the grating slide cable wrap is now much easier to package.

SLIT MASK SYSTEM
The slit mask system has been re-assembled with additional stiffening and is ready for functional testing. The radius of curvature of the mask form was increased from 81.5" to 83.5" as a result of a focal-plane focus study by ORA. The new value will not be cut into the form until final modifications are made to eliminate vignetting of rays en route from the tent mirror to the grating.

RENISHAW ENCODER
Most of the Renishaw encoder for the PA drive has been installed. Testing should start at the end of May, a delay of about four weeks.

2.3 Detectors

LINCOLN CCDS
From the Phase 1 distribution, Keck selected device number W6C2. This will be the primary CCD for ESI until a better device becomes available. Details on this device can be found at the address below:
http://gardiner2.ucolick.org/~ccdev/lincoln/summary.html

Lick has received three Phase 2 devices to test. The first device was prepared using improved laser anneal procedures and had a much reduced brickwall pattern. The next two were devices that had been processed before the work to reduce the brickwall pattern was begun. In addition to a large-amplitude brickwall pattern, these CCDs had very high spurious charge, very poor charge-transfer efficiency, and very low full well. Speculation is that these problems may be caused by the failure to elevate a proper channel, but further study at Lincoln is needed. Lincoln believes that many other Phase 2 CCDs will show the same problems based on preliminary testing done at Lincoln. This probably means that the yield of good devices from Phase 2 may be lower than originally expected, but we won't know for certain until more devices are tested in detail. (Indeed, this problem proved to be widespread. Lincoln has voluntarily added four extra wafers (24 devices) to the first Phase 3 run to restore the lost yield.)

The first 12-wafer lot of 150-mm diameter epi wafers for Phase 3 (DEIMOS final devices) was dropped on the clean room floor at Lincoln and destroyed. A new lot was begun immediately, but this loss will result in a one-month delay in receiving the first thinned Phase-3 CCDs (to October 1, 1998, from September 1, 1998). We have not received any devices from the initial 150-mm test run as we had previously expected. Apparently all available devices are being saved for thinning development work.

LICK/ORBIT CCDS
The work to assemble an interim mosaic of frontside Orbit 2Kx4K CCDs has begun. Aluminum nitride packages were glued together and the connectors and PC boards ordered. The eight devices for the interim mosaic have been selected. Dicing of the wafers, gluing the CCDs to the AlN packages, and wire-bonding of the complete set of eight CCDs is expected to be completed in May 1998.

2.4 Software

SECOND-GENERATION CCD CONTROLLER HARDWARE
The second-generation CCD controller hardware and software was successfully used to read out a 2Kx4K Orbit engineering-grade CCD in March. The DEIMOS flexure compensation CCD controller chassis was used for this test, as was the ESI dewar.

FIGDISP IMAGE DISPLAY PROTOCOL
The figdisp shared-memory-signaling extension to the image transmission protocol was successfully completed and tested across both SunOS and Solaris platforms. This extension allows figdisp to display real-time images without dropping any lines, even when the local X display is blocked by other operations (e.g., window move or re-size). Real-time images are now displayed more rapidly since figdisp no longer needs to repaint dropped lines. This version of figdisp was successfully used for our CCD readout tests (see second generation CCD controller hardware section below).

ENGINEERING DATA VISUALIZATION
A pre-release prototype of a graphical tool for the easy display and analysis of keyword-based engineering data was completed and tested using HIRES engineering data and simulated DEIMOS data (e.g., temperature logs, etc.). This tool was also demonstrated and installed at CARA in March.

GUI DEVELOPMENT br>Small refinements continue to be made to the dashboard software. The current release was installed for testing at CARA in March. Dashboard is also being used to develop the ESI GUI, which is being modeled after DEIMOS.

KEYWORD DATABASE AND AUTOMATED CODE GENERATION
These tools are now being used to generate the ESI keyword library and will be used to start building the DEIMOS library during Quarter 16.

DATABASE QUALITY ASSURANCE
An automated suite of database sanity-checking software was prototyped and tested. This software enforces rules to assure that the data in the database are consistent and make sense. It performs this task for all data for the three instruments currently supported (PFCAM, DEIMOS, ESI). A finished version will be provided to CARA.

IMPACTS OF ESI
As predicted, ESI continues to be the focus of the software effort, but much of this effort also benefits DEIMOS due to the significant amount of shared software between these two instruments. In fact, the number of software hours billed to DEIMOS this quarter did not decrease.

MANPOWER
Interviews were conducted for the Deputy Software Manager/Developer position in March. An offer has been made to our top candidate, and we are awaiting his response (he will arrive July 6).

2.5 Electronics
The electronics lab has focused this quarter on the Galil controller panels, the science CCD controller, the slit mask system, and the temperature monitoring systems. The Galil panels are receiving updates and changes to incorporate manual push-button control stations at the grating, slit mask, filter wheel, and TV filter wheel hatches. The front panels of the science CCD controller are being installed and wired. Circuitry for slit mask stage sensors that sense the mask in place has been designed and tested, and boards have been laid out. A high-resolution temperature sensor system with thirty temperature sensors has been purchased from Hewlett-Packard. A low-resolution system is also being tested and calibrated.

Cabling for the slit mask stage, grating stage, and TV camera stages has been run from the electronics ring to the front end of the instrument.

As noted, at the end of March, good images were read from the Lick/Orbit engineering grade CCD using the new SDSU-2 CCD controller (intended for the Flexure Compensation system). The readout noise was 5-6 electrons, which is as expected for that chip. With the performance of the SDSU-2 controller system now verified, four of the printed circuit boards in the controller are being revised to eliminate cuts and jumpered traces. The revised boards along with the other associated SDSU-2 controller boards for both the science controller and the flexure compensation controller are expected to be fabricated and delivered by the end of April.

2.6 Flexure Compensation
Aside from the successful test of the Flexure Compensation controller, no progress was made on the FC system this quarter.

2.7 Alignment
The main area of alignment study this quarter involved the mosaic detector. A plan was designed to align in X and Y (in plane) and initial tests were made. Refinements are expected next quarter. Alignment in Z (surface) is difficult (the spec is ±5 µ). We plan to pre-measure the packages, shim, and then confirm with independent Z measurements. Three methods of confirmation are being explored: 1) a Keyence laser-distance measuring device, 2) contact profilometry with the profilometer, and 3) microscopy. We have begun measurements of a partially working Orbit 2Kx2K CCD to determine the effect of contact measurement using the profilometer (the device was destroyed, eliminating that method).

The camera will be assembled and aligned mechanically and then confirmed optically. We have designed a camera support and test facility for the optics laboratory test tunnel. This facility is being built and fabricated now to test the ESI camera, and we will learn from that experience.

3. Report from the PI's:

DEIMOS' interior black paint is an important element in both its thermal and optical performance. The paint should absorb well from 0.4 to 1.1 µ ( to minimize scattered light. It should also absorb/emit well for a short interior thermal time constant. The interior of DEIMOS is primarily radiatively (as opposed to conductively or convectively) coupled. A shorter interior thermal time constant reduces temperature gradients that can alter the dimensions of the optical bench and cause misalignment errors. Tight radiative coupling by black surfaces reduces these thermal gradients and misalignments.

Simple tests of absorption and emission were carried out by shining radiation from a 100-watt bulb onto various steel surfaces. The surface treatments were bare matte steel, polished steel, and steel painted with DEIMOS paint.

The rates of rise of the temperature were recorded, and the rates of fall as the bulb was removed. From these it was determined that the absorptivity/emissivity of the paint must be very high at both 2 µ (where the bulb emission peaks) and at 10 µ (where emission from the steel surfaces peaks). To further test the 2 µ result and to determine the behavior of the paint at visible wavelengths, painted steel samples were sent out for reflectivity measurements from 0.4 to 2.5 µ ( by Optical Data Associates. At 0º incidence, reflectivity is about 5% over the entire range. Reflectivity increases at higher (glancing) angles of incidence, to about 30% at 75º, the highest angle tested. The increase at glancing angles is expected for any black surface that has not been specially roughened.

Together, these results indicate that DEIMOS' paint is suitably black at all relevant wavelengths.

In this quarter, Mast and Faber completed a study of DEIMOS camera ghost images using Zemax. The brightest ghosts are produced by reflections off the detector surface and back reflections again from camera elements. Nearly all such ghosts were found to be both large and fairly uniform. Their diameters are greater than or equal to 1000 px, and their surface brightness is down from that of a 1" star image by ~ 22 magnitudes. A handful of ghosts is smaller, with minimum diameter ~ 400 px and uneven surface brightness. Their peak surface brightness is down by ~ 15 magnitudes.

The brightest stars that can be imaged in a 1 sec exposure are about 13 mag. Their worst ghosts will therefore have a surface brightness of 28 mag per sq. arcsec, or 100 times fainter than the sky. Occasional bright stars of ~ 8 mag will produce ghosts equal to the sky. These and brighter stars should be kept out of the field of view for accurate work. A study of ghost pupils is intended for next quarter.

A study began this quarter of the physics of fringing in CCD detectors. The work is being carried out by graduate student Patrik Jonsson, supervised by Drew Phillips and Sandra Faber. Jonsson has developed code to model the intensity of detected light in a pixel as a function of CCD thickness, f-ratio, angle of incidence, and wavelength. He then used a test data set of 38 LRIS dome flats taken at various grating tilts to make a map of CCD silicon thickness. Such a map, if accurate, could be used to predict a priori the fringe phase in every pixel at any wavelength. The present map is not accurate enough for this. However, it does appear good enough to correct fringe phases in dome/flats taken at nearby (greater than or equal to 100 A) grating tilts. This technique could be used to tune afternoon flats the exact position angles used for nighttime data.

In the next quarter we will study the models further with a view to asking for engineering time on LRIS to obtain another set of dome flats with better wavelength spacing. The goal is to obtain a highly accurate thickness map. Flat fields generated from such a map might be able to replace dome flats completely. That would be an important step on the road to a long-lived calibration database.

4. Budget:
*Tables and figures not available online

The project budget and spending are summarized in Table 1. Details are shown in Tables 2, 3 and 4. By the end of the quarter we have spent approximately $4,273,500 on the project, or about 85% of the project budget.

Table 3 summarizes the expenditures of manpower. Approximately 11,700 man-hours of effort remain in the budget. These expenditures are graphed in Figure 4.

Expenditures on materials and supplies are summarized in Table 4 and are shown graphically in Figure 5. Approximately $160,000 remains in the budget for materials and supplies.

Major expenditures for the quarter were:
* In Administration for travel, project software licensing, and supplies.
* In Electronics for printed circuit boards and components.
* In Mechanical Fabrication for materials.
* In Optical Fabrication for coating the camera optics.
We are currently discussing with the SSC an estimated $500,000 overrun of the project budget. The details are planned to be covered in the next quarterly report.

5. Schedule:

The summary schedule is shown in Figure 1. We have moved the planned shipping date, and the commissioning dates from the last schedule. There are two principle causes for this change. The schedule now contains an eight-week testing period for the MIT/LL mosaic before the instrument is shipped to Hawaii. However, we do not anticipate receiving these devices before October 1998. Because of this we will not be able to have an assembled mosaic of the devices until about the end of the year. We are now planning for a ten-week shipping period for the instrument. We have learned that there is no possibility of air shipping the large pieces, which will not fit in a regular shipping container. We will need to ship these pieces by boat, and special arrangements and containerizing will need to be made. Currently we anticipate that we will be ready for a pre-ship review by March 1999, and first star light in the instrument in May 1999.

The fabrication, coating and integration of the camera optics into the camera barrel remain on the time-critical path of the project as shown in Figure 2. Since our last report David Hilyard completed Element 1 and nearly one side of Element 3. He remains on schedule. Figure 3 details the milestones for the remainder of the project.

6. Milestones:

The following is a list of milestones for the quarter from the last Quarterly Report, together with the progress made on them:
1. Receive the lens blank for Element 3 of the DEIMOS camera. The lens blank has arrived.
2. Complete Element 1 of the camera and start Elements 3 and 4. Element 1 is complete. David Hilyard has started on Element 3 and George Laopodis has started on Element 4.
3. Complete the No. 1 grating slider and counterweight system and test it. Complete the design of the flat mirror slider. Testing has begun for both items.
4. Complete the mechanical fabrication of the dewar system and leak test it. Mechanical fabrication is complete and testing has begun.
5. Start detailed design of the filter wheel system. Design of the filter wheel system is expected to resume in April; was delayed by ESI.
6. Complete the modifications and test the slit mask system. The slit mask system is ready for functional testing. Some additional modifications to the mask frame are required to minimize vignetting.
7. Complete the fabrication drawings for the camera and start fabrication of the camera barrel. Drawings are complete and fabrication has begun.
8. Install the new rotational encoder on DEIMOS and have motor-driven instrument rotation once again. The encoder is mechanically installed and awaiting integration of the Renishaw tape and heads.
9. Install the electronics panels on the rotating part of DEIMOS. The first panel has been installed; the second is ready for installation.
10. Install the cable chain. This was installed and then removed pending redesign.
11. Start fabrication of the hand paddles. Hand paddles are complete.
12. Run an Orbit 2Kx4K CCD with the Leach-2 FC CCD Controller. Done.
13. Run a single Orbit CCD with the Leach-2 controller in the ESI dewar. Done.
14. Fabricate the LN2 can. Done.
15. Fabricate the science dewar body. Done.
16. Finish the test dewar. Done.
17. Begin work on the database quality assurance suite and conduct prototype tests. Done.
18. Configure and install the DEIMOS instrument computer (Ultraserver 450 donated by Sun). Done.
19. Begin work on the engineering data visualization tool and conduct prototype tests. Done.
20. Use the Leach-2 CCD controller and figdisp software to read out, display in real-time time, and record-to-disk images from a frontside-illuminated Orbit 2K x 4K engineering-grade CCD. Done.
21. Complete the recruitment for a Deputy Software Manager/Developer position. Interviews completed. Offer was extended to top candidate and is awaiting his response. [He has accepted.]
22. Order the filters. This item is still pending.
23. Finalize the coating contract with Coherent. Done.
24. Carry out a study of ghost images and ghost pupils. Ghost images are complete; pupils still pending.
25. Design and purchase the temperature sensor system, including the controller unit and sensors. Done.

Milestones for the next quarter:
1. Complete fabrication of the camera optics.
2. Coat elements 1, 2, 3, 4, 5, 7, 8, 9 and the dewar window.
3. Complete all parts for the camera barrel.
4. Build a mosaic of Orbit chips.
5. Install the Orbit mosaic of chips into science dewar.
6. Complete the science CCD controller.
7. Start electrical tests of the science dewar.
8. Read out two Orbit chips in the test dewar.
9. Complete and test the slit mask system.
10. Complete the grating system.
11. Complete testing of the Renishaw encoder on the PA rotational stage.
12. Balance DEIMOS and continue testing of rotational drive.
13. Glue mounting hardware on the tent mirror.
14. Order the filters.
15. Select the optical couplant based on reactivity tests.
16. Select the calibration lamp sources.
17. Select the light source for the FC system.
18. Finish the ghost pupil study.
19. Produce an alignment and test plan for the camera optics.
20. Complete the design of the filter wheel.
21. Complete the cable wrap.
22. Specify and order RAID disk controller for the DEIMOS instrument computer.
23. Begin work on converting HIRES-specific Image Rotator software into a generic image/instrument rotator task. Test using the NIRSPEC rotator.
24. Implement and test waveforms for MIT/LL 2Kx4K CCD, and read out a single MIT/LL CCD using ESI dewar.
25. Implement and test mosaic descrambling routines and waveforms, using these to read out a 2x1 mosaic of front-side illuminated 2Kx4K Orbit CCDs mounted in the new test dewar.
26. Use engineering data visualization tool to analyze servo performance of various stages.