LRIS-R Upgrade Preliminary Design Review 28 June 2007

1. LRIS-R Upgrade Preliminary Design Review 28 June 2007 Mechanical: Chris Lockwood Electronics: Chris Wright, Michael Peck CCDs: Richard Stover Software: Bob Kibrick Project Manager: Dave Cowley Co-PIs: Mike Bolte, Connie Rockosi

2. LRIS-R Upgrade • Activities since Phase A completion • Brief status of major subsections • Schedule/budget going forward

3. Activities • Design of new focus mechanism • Design of custom dewar • CCD controller board set determined • Boards running in test-bed with refit dewar • Electronics packaging design completed • Test fit mockup of the new dewar plus associated electronics and cabling • CCD characterization

4. CCD News • The inconsistent performance of amplifiers has been traced to stresses induced by the flex cabling. Designed and built a stabilizing fixture and now have several devices with two working amplifiers • Completed the UCO QE measurement station and results are now consistent with 1-reflectivity measurements

5. CCD QE • Three good devices: 1-13, 1-12, 1-15. Device 1-11 may be a viable alternate.

6. CCD Summary CCD Package Amps Noise QE Peak Thick/Tilt Notes Num Date e-, 8μs (Å) μm 1-13 4/2006 L+R 7L,5R 93%@9000 8776/2 1-12 1/2005 L+R 10L,20R 94%@9400 8776/2 1-15 1/2006 L+R NDL,11R 94%@7600 8779/1 stress fractures re-test 6/28 1-11 7/2004 L+R 4L,NDR 91%@9100 8573/53 Charge injection right side All readnoise measurements being redone with new serial clocking scheme. Tests on 1-11 show significantly lower measured noise, probably due to reduced spurious charge.

7. Mechanical Upgrades • Rapid Simple installation • Fine adjustment of the dewar in 3 axes • Precise dewar relocation on re-installation (possibly with no adjustment required). • Greater than 24hr hold time. • Reduced vacuum maintenance (Ion pump)

8. Mechanical Features & Comparisons • Upgrade - +6lbs but 5% less moment on camera barrel • Installation accessibility tested successfully in mockup • Kinematic Dewar Replacement (no adjustment) shows promise (testing req’d)

9. Mechanical Features & Comparisons • Focus resolution as good or better (< 2micron) than current • Total CCD flexure motion relative to camera axis: • Tilt = 4microns defocus • Pointing = 1 pixel

10. Electronics • SDSU-II CCD controller boards maintain compatibility with other systems at Keck • LBNL bias voltage board • Custom preamp and analog switch boards for LBNL CCDs • Independent CCD voltage monitoring at the electronics box • Concept for board layouts and overall packaging successfully evaluated in a test-fit in April. • Prototype during design and development phase

11. Dewar and Electronics Box block diagram, showing internal connections and cabling to the CCD Controller. Form factors checked in April test fit at summit • CCD signal (analog) switches • Preamplifiers • CCD signal level monitor analog circuits • Power over Ethernet • DC/DC converters and DC regulators • Ethernet and optically-isolated I2C interfaces for CCD signal monitor

12. CCD Controller block diagram, showing internal printed circuit boards and their interconnections. Also shown is the external cabling to the dewar electronics box and power supply chassis. Most of these boards are now running with the test dewar at Santa Cruz. • SDSU-II boards • LBNL CCD bias voltage board • Shutter control • I2C power control and monitoring over Ethernet

13. New and Updated Software For LRIS-R • CCD controller and VME crate software • Completely replace existing software for LRIS-R CCD controller and VME crate • Modeled on the DEIMOS mosaic software • Instrument computer software (w/Cromer @ CIT) • Update existing LRIS-R keyword library • Replace image capture software (lickserv1 -> lickserv2) • Replace image display software (figdisp -> DS9)

14. Changes From Phase-A Software Plan • Phase A Software Plan • Left LRIS blue side COMPLETELY untouched • Retained figdisp for both red and blue sides • Retained use of non-compliant FITS mosaics • PDR Analysis • Phase A plan not cost effective nor maintainable • At same effort level, upgrade both sides to DS9 • PDR plan leaves LRIS blue MOSTLY untouched • Better meets needs of LRIS users and WMKO

15. PDR Software Plan: Minimal Changes to LRIS Blue • No hardware or software changes to: • LRIS-B CCD controller • LRIS-B VME crate • Only modest changes to LRIS-B instrument computer software • Update lickserv2 and LRIS-B keyword library • Changes being tested now using spare LRIS computer at Keck • Tests use actual LRIS blue when LRIS not in use

16. Phase A PDR PDR Feb 2007 June 28, 2007 DDR Jan 2008 Preship Review Dec 2008 First Light Jan 2009 Schedule Aug 2007 June 2008 Aug 2008

17. Budget Phase A PDR Cost to completion: $1.23M $1.16M • Changes: • + CCD testing • + Focus Mechanism • - CCD Controller Total project cost: $1.575M

22. Readnoise thoughts • Probably will bin 22 • 1 slit projects to 7.4 pixels in spatial direction • 1 slit gives FWHM of ~7 pixels in dispersion direction • 6e- readout: ~35 sec • Sky counts=RN2 • ~30s unbinned • ~7s binned [24µ pixel case- 0.39(QE ratio) for new chips]

23. Propose to align the gap the same way as LRIS-B. Hide some of the gap behind the slitmask bar. Offset from center to align with LRIS-B gap edge.

24. CCDs: • Two good devices and one outstanding device. 1-15, 1-17 and 1-13. • All CARA devices now packaged and characterized • 4k x 4k devices designed but because of problems at Dalsa, no runs have happened yet.

25. Current CCD CCDs • Improved QE • Zero fringing • P-V flatness ≤ 9µm • 134 seconds unbinned/1 amp: 6e- • 50 seconds unbinned/1amp: 9e- • 1-13, two good amps, 1-17, 1-15 one good amp, one noisy

26. Custom dewar: 24 hour hold time, fits into available space. accommodates special shielding

27. Cooling options • Preferred option is a redesign of the dewar focus mechanism to allow a larger-volume LN2 can. Looks good and gives predicted 25.7 hour hold time.

28. New focus mechanism, dewar mount and adjustment features are advanced to beyond PDR level.

29. Schedule/Budget • Software-lite version: 24 months/$1.3M (no contingency). Could start in July. • Misc: • as-built LRIS-R documentation much improved • Good review. Scientists/engineers/Keck

30. Software • Match current LRIS-B (Figdisp + xpose) and retain current LRIS-R keyword library. No changes to LRIS-B: • Downsides with favored option are the LRIS-B FITS format does not conform to CCD mosaic standards and figdisp does not support WCS coordinates

31. Backup Slides from previous SSC reports