Radiation drive in laser‐heated hohlraums

Nearly 10 years of Nova [E. M. Campbell, Laser Part. Beams 9, 209 (1991)] experiments and analysis have lead to a relatively detailed quantitative and qualitative understanding of radiation drive in laser‐heated hohlraums. Our most successful quantitative modeling tool is two‐dimensional (2‐D) LASNEX numerical simulations [G. B. Zimmerman and W. L. Kruer, Comments Plasma Phys. Controlled Fusion 2, 51 (1975)]. Analysis of the simulations provides us with insight into the physics of hohlraum drive. In particular we find hohlraum radiation conversion efficiency becomes quite high with longer pulses as the accumulated, high‐Z blow‐off plasma begins to radiate. Extensive Nova experiments corroborate our quantitative and qualitative understanding.

[1]  Rosen,et al.  High temperatures in inertial confinement fusion radiation cavities heated with 0.35 microm light. , 1994, Physical review letters.

[2]  Robert L. Kauffman,et al.  Measurement of 0.1-3-keV x rays from laser plasmas , 1986 .

[3]  Murakami,et al.  Experimental observation of laser-induced radiation heat waves. , 1990, Physical review letters.

[4]  Goldstein,et al.  Effect of configuration widths on the spectra of local thermodynamic equilibrium plasmas. , 1995, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[5]  Herrmann,et al.  X-ray generation in a cavity heated by 1.3- or 0.44- microm laser light. I. Time-integrated measurements. , 1988, Physical review. A, General physics.

[6]  E. Campbell.  Recent results from the Nova program at LLNL , 1991 .

[7]  Turner,et al.  Modeling and interpretation of Nova's symmetry scaling data base. , 1994, Physical review letters.

[8]  Murakami,et al.  X-ray confinement in a gold cavity heated by 351-nm laser light. , 1991, Physical review. A, Atomic, molecular, and optical physics.

[9]  Peter A. Amendt,et al.  Design and modeling of ignition targets for the National Ignition Facility , 1995 .

[10]  Tsakiris,et al.  X-ray generation in a cavity heated by 1.3- or 0.44- microm laser light. III. Comparison of the experimental results with theoretical predictions for x-ray confinement. , 1988, Physical review. A, General physics.

[11]  Douglass E. Post,et al.  Steady-state radiative cooling rates for low-density, high-temperature plasmas , 1977 .

[12]  John H. Nuckolls,et al.  The feasibility of inertial‐confinement fusion , 1982 .

[13]  Tsakiris,et al.  Modeling of plasma dynamics in x-ray-confining cavities. , 1993, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.