UCRL-TR-230900 Gemini Planet Imager: Preliminary Design Report B. Macintosh May 11, 2007 GPI PDR Gemini Planet Imager Preliminary Design Document Volume 2 – Instrument Design Lawrence Livermore National Laboratory National Research Council, Herzberg Institute of Astrophysics National Science Foundation Center for Adaptive Optics University of California, Los Angeles Jet Propulsion Laboratory University of California, Santa Cruz American Museum of Natural History Université de Montréal University of California, Berkeley Preliminary Design Documents Volume 1 – Scientific Motivation Volume 2 – Instrument Design Volume 3 – Software Documents Volume 4 – Management Description UCLR-TR-230900 GPI-PROJ_SYS-017 May 28, 2007 Page 1 of 374 GPI PDR This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes. This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48. May 28, 2007 Page 2 of 374 GPI PDR Table of Contents 1 OVERVIEW ...................................................................................................................... 10 1.1 Document roadmap...................................................................................................................................................11 1.2 Instrument Overview ................................................................................................................................................12 1.3 Subsystem descriptions .............................................................................................................................................15 1.3.1 Adaptive Optics (AO) subsystem (Chapter 3) ........................................................................................................15 1.3.2 Coronagraph subsystem..........................................................................................................................................16 1.3.3 Calibration (CAL) subsystem .................................................................................................................................17 1.3.4 Science Integral Field Spectrograph (IFS) subsystem ............................................................................................19 1.3.5 Opto-Electric-Mechanic Superstructure (OMSS)...................................................................................................20 1.3.6 Top Level Computer (TLC) and instrument software ............................................................................................20 1.3.7 Simulations and expected performance ..................................................................................................................21 1.3.8 Risk areas................................................................................................................................................................22 2 SYSTEMS ENGINEERING .............................................................................................. 24 2.1 GPI contrast design philosophy................................................................................................................................24 2.2 Assumed Wave-Front Disturbances ........................................................................................................................27 2.2.1 Atmospheric Turbulence ........................................................................................................................................28 2.2.2 Windshake ..............................................................................................................................................................29 2.2.3 Optical surfaces ......................................................................................................................................................29 2.3 Performance simulations and contrast predictions ................................................................................................30 2.3.1 Static aberration modeling......................................................................................................................................30 2.3.2 Dynamic AO simulations .......................................................................................................................................32 2.4 Requirements: AO correction ..................................................................................................................................32 2.5 Data/control flows......................................................................................................................................................33 2.6 Throughput budget ...................................................................................................................................................35 2.7 Flexure & alignment budget.....................................................................................................................................36 2.7.1 Alignment Budget...................................................................................................................................................37 2.7.2 Opto-mechanical Flexure and Thermal Effects ......................................................................................................38 2.8 Preliminary alignment plan......................................................................................................................................41 2.9 Mass and Balance Budget.........................................................................................................................................42 2.10 Thermal budget .........................................................................................................................................................42 2.10.1 Electronics Enclosures Power............................................................................................................................43 2.10.2 Optics enclosure.................................................................................................................................................43 2.11 Upward ISS Only Advantages..................................................................................................................................43 2.12 Gemini Spares Philosophy........................................................................................................................................44 May 28, 2007 Page 3 of 374 GPI PDR 2.13 Key issues ...................................................................................................................................................................44 2.13.1 Risk analysis and mitigation ..............................................................................................................................44 2.13.2 Technology Risk Areas......................................................................................................................................45 2.14 Trade studies summary.............................................................................................................................................46 2.15 ICDs............................................................................................................................................................................46 2.15.1 External (Gemini) ICDs.....................................................................................................................................47 2.15.2 Internal ICDs (SW 9).........................................................................................................................................47 2.16 Reliability, Availability and Maintainability (SE 12) .............................................................................................48 2.17 Safety ..........................................................................................................................................................................49 2.18 Chapter 2 Appendices ...............................................................................................................................................49 3 AO SUBSYSTEM............................................................................................................. 50 3.1 Overview and requirements .....................................................................................................................................50 3.2 AO system summary .................................................................................................................................................50