Stability of optical elements in the NIF target area building Metadata

Title

• Main Title Stability of optical elements in the NIF target area building

Creator

• Author: Foley, R J
  Creator Type: Personal
• Author: Shaw, G S
  Creator Type: Personal
• Author: Trummer, D J
  Creator Type: Personal

Contributor

• Sponsor: United States. Department of Energy. Office of the Assistant Secretary for Defense Programs.
  Contributor Type: Organization
  Contributor Info: USDOE Office of Defense Programs (DP)

Publisher

• Name: Lawrence Livermore National Laboratory
  Place of Publication: Livermore, California
  Additional Info: Lawrence Livermore National Laboratory, Livermore, CA

Date

• Creation: 1998-08-01

Language

• English

Description

• Content Description: The Target Area Building (TAB) of the National Ignition Facility (NIF) is 300 feet long, 100 feet wide, and 100 feet tall and is comprised of a cylindrical target building and two switchyard space frames. The reinforced concrete target building houses the target chamber, target positioner, turning mirrors, final optics assemblies, and diagnostics, while the steel switchyard space frames support turning mirrors and diagnostic equipment. Within the TAB, the 192 independent laser beams of the NIF laser system are required to be accurately positioned. In order to satisfy the engineering system requirement for optical system positioning (stability on target), the TAB must provide a stable platform for optical elements before and during a shot. This paper summarizes the stability analyses that were performed in support of the TAB and optical system design. Sources that influence optic stability are structural excitations, such as ambient and wind induced vibrations, and thermal transients, such as diurnal and HVAC temperature changes. A positioning error budget has been developed for the NIF project for use in the design and evaluation of structures which support optical elements. To satisfy the error budget requirements, vibrational stability will be achieved through a combination of facility design, optic support structure design, and passive damping. Thermal stability will be accomplished by using high thermal-mass concrete structures, conditioned air flow, and a reduction of heat sources. Finite element analysis has been used to evaluate the design of the TAB and optical support structures. A detailed structural model of the TAB that includes the target positioner, target chamber, turning mirrors, and diagnostics, has been used for stability evaluations. Finite element analyses covering ambient ground vibration, thermal loads, pressure fluctuations, and wind excitations have demonstrated that the current design of the TAB provides a stable platform for maintaining beam alignment.
• Physical Description: 516 Kilobytes

Subject

• Keyword: Us National Ignition Facility
• Keyword: Laser Mirrors
• STI Subject Categories: 70 Plasma Physics And Fusion
• Keyword: Mechanical Vibrations
• Keyword: Finite Element Method

Source

• Conference: 3rd Annual International Conference on Solid State Lasers for Application to Inertial Confinement Fusion (ICF), Monterey, CA, June 7-12, 1998

Collection

• Name: Office of Scientific & Technical Information Technical Reports
  Code: OSTI

Institution

• Name: UNT Libraries Government Documents Department
  Code: UNTGD

Resource Type

• Article

Format

• Text

Identifier

• Other: DE00003711
• Report No.: UCRL-JC-129682
• Grant Number: W-7405-Eng-48
• Office of Scientific & Technical Information Report Number: 3711
• Archival Resource Key: ark:/67531/metadc687407