Application of adaptive optics for controlling the NIF laser performance and spot size

Conference · Mon Aug 17 04:00:00 EDT 1998

OSTI ID:2841

Auerbach, J ^[1]; Bliss, E; Henesian, M; Lawson, J; Manes, K; Renard, P; Sacks, R; Salmon, T; Trenholme, J; Williams, W; Winters, S; Zacharias, R

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1. LLNL

The National Ignition Facility (NIF) laser will use a 192-beam multi-pass architecture capable of delivering several MJ of UV energy in temporal pulse formats varying from sub-ns square to 20 ns precisely-defined high-contrast shapes. Each beam wavefront will be subjected to effects of optics inhomogeneities, figuring errors, mounting distortions, prompt and slow thermal effects from flashlamps, driven and passive air-path turbulence, and gravity-driven deformations. A 39-actuator intra-cavity deformable mirror, controlled by data from a 77-lenslet Hartman sensor will be used to correct these wavefront aberrations and thus to assure that stringent farfield spot requirements are met. We have developed numerical models for the expected distortions, the operation of the adaptive optic system, and the anticipated effects on beam propagation, component damage, frequency conversion, and target-plane energy distribution. These models have been extensively validated against data from LLNL's Beamlet, and Amplab lasers. We review the expected beam wavefront aberrations and their potential for adverse effects on the laser performance, describe our model of the corrective system operation, and display our predictions for corrected-beam operation of the NI

• Research Organization: Lawrence Livermore National Lab., CA (US)
• Sponsoring Organization: USDOE Office of Defense Programs (DP) (US)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 2841
• Report Number(s): UCRL-JC-130028; 39DP02000; 39DP02000
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BEAM DYNAMICS
CONTROL EQUIPMENT
ENERGY SPECTRA
INERTIAL CONFINEMENT
MATHEMATICAL MODELS
MIRRORS
OPTICS
PERFORMANCE
SOLID STATE LASERS
US NATIONAL IGNITION FACILITY