8 LASER FACILITY FUNCTIONAL REQUIREMENTS Note to reader: This is a draft version and is written to capture major points. In particular capture requirements that are specific to NGAO and perhaps different from K1 and K2 LGS systems. Some parts of documentation from K1 and K2 LGS projects could be adapted for this exercise will be done in detail at a later stage. 8.1 Context diagram Figure 1: Contextual representation of the LGS Facility showing control and data lines to different sub-systems within LGSF and those that facilitate its interface to the AO system.8.2 Architectural Assumptions and Overall Requirements Introduction and scope: this subsection describes the requirements for the NGAO laser guide star facility sub-system. NGAO is envisioned as a multi-guide star. The laser guide star facility includes the laser, the LTA, the beam transport from laser to LTA, safety and diagnostic systems. The document also defines the interface requirements that will need to be met. Glossary: TBD - To be looked up TBWO - To be worked out TBLU - To be looked up Shall - necessity Should - goal Will - Statement of fact. Long term - Short term - Low power - MTBF - Mean time before failure 8.2.1 Architectural Assumptions Some assumptions are (and have to be) explicitly stated as requirements 1. The design shall have 9 LGS beacons. [Requirement arises from architectural design choices made, science requirements on the FoV and EBS] 2. There is a central beacon with 5 beacons arranged on equidistant from each other on a circle of radius varying from 11”-101”. [Requirement arises from architectural design choices made, science requirements on the FoV and EBS] 3. There are 3 roving beacons to perform MOAO on tip-tilt stars that can be independently pointed anywhere in the 202” FoV. [Requirement arises from architectural design choices made, science requirements on the FoV and EBS] 4. The asterism shall be fixed with respect to the sky. [AO system simplicity] 5. Median Na layer altitude = 90 Km [legacy literature] 6. Maximum vertical Na layer speed = 30 m/s [from EBS for focus change effects] 7. Each beacon has its own tip tilt (or a dedicated TT in front of the HOWFS for each beacon?). [Arch. choice still to be made] 8. Baseline design has no higher order uplink correction. [Baseline design accepted during design down selection, may change depending on uplink AO TS?] 9. The LLT shall be mounted behind the secondary, on-axis w.r.t. the Keck telescope optics axis. [Architectural choice to reduce spot elongation effects] 10. All performance specifications are stated at "median conditions" [] 11. The LGS WFS module with 9 LGS WFS’s shall be mounted on a turn-table. [Even if the asterism is fixed w.r.t. the sky there are observations with the pupil being fixed which will need this mode] 12. The sodium density at the Mesospheric sodium column density is 4*10^9 (atoms/cm^2) [from Error Budget Spreadsheet (EBS)]13. The LGS facility sub-system and all its components shall conform to Industry Consensus Standards as described in Table below. [Defining industry standards] Source (Organization or Standardizing Body) Number Title ANSI Y14.5M-1994 (R1999) Dimensioning and Tolerancing ANSI Y14.1-1995 (R2002) Decimal Inch Drawing Sheet Size And Format ANSI Y14.34-2003 Parts Lists, Data Lists, And Index Lists: Associated Lists ANSI Y14.3M-1994 Multi And Sectional View Drawings ANSI / ASME Y14.18M-1986 Optical Parts (Engineering Drawings and Related Documentation Practices) ASME HPS-2003 High Pressure Systems ASME Y14.100-2000 Engineering Drawing Practices ASME Y32.10-1967 (R1994) Graphic Symbols for Fluid Power Diagrams ASTM E595-93 (2003)e1 Standard Test Method for Total Mass Loss and Collected Volatile Condensable Materials from Outgassing in a Vacuum Environment ATA Spec 300-2001.1 Specification for Packaging of Airline Supplies CENELEC EN 50082-1:19971 Electromagnetic compatibility – Generic immunity standard – Part 1: Residential, commercial and light industry Council of the European Communities EMC 89/336/EEC1 Council Directive 89/336/EEC of 3 May 1989 on the approximation of the laws of the Member States relating to electromagnetic compatibility (EMC Directive) County of Hawaii 1995 edition Hawaii County Code 1983 (1995 edition) Department of Defense MIL- STD-171E Finishing of Metal and Wood Surfaces Department of Defense MIL-HDBK-217F-21 Reliability Prediction of Electronic Equipment 1. This reference for information only. Table 1: Referenced Standards, continued Source (Organization or Standardizing Body) Number Title Department of Defense MIL-STD-810F Test Method Standard for Environmental Engineering Considerations and Laboratory Tests EIA EIA-310-D Cabinets, Racks, Panels, and Associated Equipment EIA EIA-6491 National Consensus Standard ForConfiguration Management FCC Title 47 CFR Part 151 Radio Frequency Devices IEEE 802.3U revision 95 Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method & Physical Layer Specifications: Mac Parameters, Physical Layer, Medium Attachment Units and Repeater for 100 Mb/S Operation (Version 5.0) IEEE 1012-2004 Standard for Software Verification and Validation International Code Council (ICC) IBC-2006 2006 International Building Code® ISO/IEC ISO / IEC 12207:1995 Information Technology - Software life cycle processes National Electric Manufacturers Association 250-1997 Enclosures for Electrical Equipment (1000 Volts Maximum) National Fire Protection Association (NFPA) NFPA 55, 2005 edition Standard for the Storage, Use, and Handling of Compressed Gases and Cryogenic Fluids in Portable and Stationary Containers, Cylinders and Tanks NFPA NFPA 70, 2005 edition National Electric Code NFPA NFPA 99C, 2005 edition Standard on Gas and Vacuum Systems Naval Surface Warfare Center NSWC 98/LE11 Handbook of Reliability Prediction Procedures for Mechanical Equipment OSHA Title 29 CFR Part 1910 Occupational Safety And Health Standards Telcordia GR-63-CORE NEBS™ Requirements Source (Organization or Standardizing Body) Number Title TIA/EIA TIA/EIA-568-B Commercial Building Telecommunications Cabling Standards Underwriters Laboratories Inc. Standard for Safety 508 Industrial Control Equipment 1. This reference for information only. 14. Lifetime of the LGS facility sub-system