Final optics for laser-driven inertial fusion reactors

Conference · Wed Oct 02 00:00:00 EDT 1991

OSTI ID:5806527

Woodworth, J G; Chase, L L; Guinan, M W; Krupke, W F; Sooy, W R

If Inertial Confinement Fusion (ICF) power plus utilizing laser drivers are to be considered for electrical power generation, a method for delivering the driver energy into the reactor must be developed. This driver-reactor interface will necessarily employ final optics,'' which must survive in the face of fast neutrons, x-rays, hot vapors and condensates, and high-speed droplets. The most difficult to protect against is fast neutron damage since no optically transmissive shielding material for 14-MeV neutrons is available. Multilayer dielectric mirrors are judged to be unsuitable because radiation-induced chemical change, diffusion, and thickness changes will destroy their reflectivity within a few months of plant operation. Recently, grazing incidence metal mirrors were proposed, but optical damage issues are unresolved for this approach. In this study, we considered the use of refractive optics. A baseline design consists of two wedges of fused silica, which put a dogleg into the beam and thus remove optics further upstream from direct sight of the reactor. If the closest optic were located 40 m from the center of a 3 GW{sub t} reactor it would be subject to an average 14-MeV neutron flux of {approx}5 {times} 10{sup 12} n/s-cm{sup 2} with a peak flux of {approx}6 {times} 10{sup 18} n/s-cm{sup 2}. A major question to be answered is: what duration of reactor operation can this optic withstand '' To answer this question we have reviewed the literature bearing on radiation-induced optical damage in fused silica and assessed its implications for reactor operation with the baseline final optics scheme. It appears possible to continuously anneal the neutron damage in the silica by keeping the wedge at a modestly elevated temperature.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5806527
• Report Number(s): UCRL-JC-108464; CONF-910968-70; ON: DE92008617
• Resource Relation: Conference: 14. IEEE symposium on fusion engineering, San Diego, CA (United States), 30 Sep - 3 Oct 1991
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
LASER FUSION REACTORS
BEAM OPTICS
DAMAGING NEUTRON FLUENCE
INERTIAL CONFINEMENT
LASER-PRODUCED PLASMA
PERFORMANCE
PHYSICAL RADIATION EFFECTS
SILICA
CHALCOGENIDES
CONFINEMENT
MINERALS
NEUTRON FLUENCE
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PLASMA
PLASMA CONFINEMENT
RADIATION EFFECTS
SILICON COMPOUNDS
SILICON OXIDES
THERMONUCLEAR REACTORS
700411* - Inertial Confinement Devices- (1992-)