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Return To: Session FT/1 - Technology Developments
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(FT/1-3Rb) Design and Fabrication of Form-insulated Cryogenic Target for Wet-walled Laser Fusion

T. Norimatsu1), T. Takeda1), K. Nagai1), K. Mima1), T. Yamanaka1)
1) Institute of Laser Engineering, Osaka University, Osaka, Japan

Abstract.  In a future laser fusion reactor with a liquid first wall, cryogenic targets with thin ablator are hard to survive due to strong surface heating caused by adsorption of metal vapor in the reactor. Because of the large latent heat of condensation of metal vapor, almost all molecules collide with the cold target surface condense on the surface. To prevent the melting, we propose a foam-insulated target that has a middle density foam layer. Requirements for the foam layer are a) appropriate thermal insulation, b) minimum influence on the gain, c) sufficient mechanical strength for the acceleration, and d) capability of mass production. We successfully fabricated a foam shell coated with a gas barrier and a plastic shell coated with a foam layer by emulsion process followed by interfacial polycondensation. Although the diameters were less than 1mm, basic technologies for mass production were demonstrated. Simulation result also indicated that coating of the foam layer could be possible without reducing the target gain.

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IAEA 2003