Tools for Predicting Optical Damage on Inertial Confinement Fusion-Class Laser Systems

Nostrand, M C ; Carr, C W ; Liao, Z M ; Honig, J ; Spaeth, M L ; Manes, K R ; Johnson, M A ; Adams, J J ; Cross, D A ; Negres, R A ; Widmayer, C C ; Williams, W H ; Matthews, M J ; Jancaitis, K S ; Kegelmeyer, L M

Lawrence Livermore National Laboratory

关键词: Probability;    Monitoring;    Wavelengths;    Implementation;    Lasers;   

DOI  :  10.2172/1018829
RP-ID  :  LLNL-TR-464836
RP-ID  :  W-7405-ENG-48
RP-ID  :  1018829

美国|英语

来源: UNT Digital Library

【 摘 要 】

Operating a fusion-class laser to its full potential requires a balance of operating constraints. On the one hand, the total laser energy delivered must be high enough to give an acceptable probability for ignition success. On the other hand, the laser-induced optical damage levels must be low enough to be acceptably handled with the available infrastructure and budget for optics recycle. Our research goal was to develop the models, database structures, and algorithmic tools (which we collectively refer to as ''Loop Tools'') needed to successfully maintain this balance. Predictive models are needed to plan for and manage the impact of shot campaigns from proposal, to shot, and beyond, covering a time span of years. The cost of a proposed shot campaign must be determined from these models, and governance boards must decide, based on predictions, whether to incorporate a given campaign into the facility shot plan based upon available resources. Predictive models are often built on damage ''rules'' derived from small beam damage tests on small optics. These off-line studies vary the energy, pulse-shape and wavelength in order to understand how these variables influence the initiation of damage sites and how initiated damage sites can grow upon further exposure to UV light. It is essential to test these damage ''rules'' on full-scale optics exposed to the complex conditions of an integrated ICF-class laser system. Furthermore, monitoring damage of optics on an ICF-class laser system can help refine damage rules and aid in the development of new rules. Finally, we need to develop the algorithms and data base management tools for implementing these rules in the Loop Tools. The following highlights progress in the development of the loop tools and their implementation.