학술논문
Demonstration of hot-spot fuel gain exceeding unity in direct-drive inertial confinement fusion implosions
Document Type
Original Paper
Author
Williams, C. A.; Betti, R.; Gopalaswamy, V.; Knauer, J. P.; Forrest, C. J.; Lees, A.; Ejaz, R.; Farmakis, P. S.; Cao, D.; Radha, P. B.; Anderson, K. S.; Regan, S. P.; Glebov, V. Yu; Shah, R. C.; Stoeckl, C.; Ivancic, S.; Churnetski, K.; Janezic, R. T.; Fella, C.; Rosenberg, M. J.; Bonino, M. J.; Harding, D. R.; Shmayda, W. T.; Carroll-Nellenback, J.; Hu, S. X.; Epstein, R.; Collins, T. J. B.; Thomas, C. A.; Igumenshchev, I. V.; Goncharov, V. N.; Theobald, W.; Woo, K. M.; Marozas, J. A.; Bauer, K. A.; Sampat, S.; Waxer, L. J.; Turnbull, D.; Heuer, P. V.; McClow, H.; Ceurvorst, L.; Scullin, W.; Edgell, D. H.; Koch, M.; Bredesen, D.; Johnson, M. Gatu; Frenje, J. A.; Petrasso, R. D.; Shuldberg, C.; Farrell, M.; Murray, J.; Guzman, D.; Serrato, B.; Morse, S. F. B.; Labuzeta, M.; Deeney, C.; Campbell, E. M.
Source
Nature Physics. 20(5):758-764
Subject
Language
English
ISSN
1745-2473
1745-2481
1745-2481
Abstract
Irradiating a small capsule containing deuterium and tritium fuel directly with intense laser light causes it to implode, which creates a plasma hot enough to initiate fusion reactions between the fuel nuclei. Here we report on such laser direct-drive experiments and observe that the fusion reactions produce more energy than the amount of energy in the central so-called hot-spot plasma. This condition is identified as having a hot-spot fuel gain greater than unity. A hot-spot fuel gain of around four was previously accomplished at the National Ignition Facility in indirect-drive inertial confinement fusion experiments where the capsule is irradiated by X-rays. In that case, up to 1.9 MJ of laser energy was used, but in contrast, our experiments on the OMEGA laser system require as little as 28 kJ. As the hot-spot fuel gain is predicted to grow with laser energy and target size, our work establishes the direct-drive approach to inertial fusion as a promising path towards burning and ignited plasmas in the laboratory. Additionally, we report a record (direct-drive) fusion yield of 0.9 kJ on OMEGA, which we achieved with thin-ice deuterium–tritium liner targets.
Inertial confinement fusion experiments in a direct-drive configuration report more energy produced in deuterium–tritium fusion reactions than the amount of energy in the central part of the plasma created by laser irradiation of the fuel capsule.
Inertial confinement fusion experiments in a direct-drive configuration report more energy produced in deuterium–tritium fusion reactions than the amount of energy in the central part of the plasma created by laser irradiation of the fuel capsule.