Engineering and Design Issues for the New HIRES CCD on the Keck I Telescope zVacuum Challenges yIncreased O-Rings zHigher Thermal Load zDesign Modifications yElimination of support ring ySwitch to silver yChange in support straps
Cooling Path to CCD’s Cold Finger CF Clamps CF Mating Block Main Strap Thermal Spider Extension Thermal Spider CCD Strap Assembly CCD Moly Base CCD
Temperature Changes Across the System
Hold Time Test for LN 2 Measuring the depth of LN 2 Original test (Test #1) was completed in Jan 2002, with stainless steel support strap in place. This test duplicated the methods, with a few minor exceptions
Results: Black plastic wand with frosty condensation Ruler 1. Error discovered in Test 1 measuring technique 2. Small changes in ambient temp. found to be significant 3. Hold time increased for all heat loads once the stainless steel support ring was removed.
Test 1 ~ With copper cold finger and stainless steel support ring Test 2 ~ With copper cold finger and no support ring Test 3 ~ With silver cold finger and no support ring Comparative Hold Times for LN 2
Theoretical Vs. Experimental Results for Heat Load Due to Radiation
This project was supported by a Research Experiences for Undergraduates (REU) supplement to the National Science Foundation Science and Technology Center for Adaptive Optics, managed by the University of California at Santa Cruz under cooperative agreement No AST My heartfelt thanks to : To Geri Philley and Lisa Hunter, and everyone at the Center for Adaptive Optics, for making this internship possible The entire crew at Lick Engineering, but especially to my wonderful research supervisors, Jerry Cabak, Terry Pfister, and to Deb Culmer, whose tech support kept me sane. Thank you: Itchung Cheung and the ACCESS program for taking the UCSC CfAO interns under your wing for the summer, Peggy Church and Sue Tappero from the Cabrillo College MESA program for telling me about the internship, Steve Vogt, for taking the time to answer my questions so thoroughly, and Laura Kraft (from Keck) and Roger Ressmeyer (formerly of Corbis) for the beautiful photos. Also, to Bruce Atwood and Thomas P. O’Brien, of Ohio State Univ., for answering my many questions. I’d like to express my gratitude to Carmen Kunz, who performed the original Hold Time Test; her write-up made my testing much easier than it would otherwise have been. Part of the Lick Engineering gang