Speaker
Description
Recent progress in cryogenic DT-layered implosion experiments on the OMEGA laser have considerably improved the prospects for achieving thermonuclear ignition and energy gains with megajoule-class lasers via direct drive. By hydrodynamically scaling the core conditions of highest performing OMEGA implosions [1], fusion yields above a megajoule are expected for 2 MJ of symmetric laser illumination [2]. Those implosions have benefited from a significant increase in implosion performance obtained through a statistical approach used in predicting implosion experiments and designing targets and laser pulse shapes [3,4] to achieve the highest implosion velocity while maintaining hydrodynamic stability. It is now possible to separate individual contributions to the yield degradation providing a more complete physics picture for each implosion. To test individual degradation mechanisms, dedicated implosion experiments have been carried out by implementing single parameter scans. Scans of the SSD (Smoothing by Spectral Dispersion) bandwidth [5,6] to study laser imprinting; scans of the stalk mount size are used to study effects of engineering features; scans of the vapor pressure are used to study the effects of higher implosion convergence. An overview of the implosion optimization effort and of the dedicated physics experiments at the OMEGA laser will be provided.
[1] C.A. Williams et al, submitted to Nature Physics (2023); C.A. Williams at this conference.
[2] V. Gopalaswamy et al, submitted to Nature Physics (2023);
[3] V. Gopalaswamy et al, Nature 565, 581-586 (2019)
[4] A. Lees et al, Phys. Rev. Lett. 125, 105001 (2021); A. Lees at this conference
[5] D. Patel et al, Submitted to Phys. Rev. Lett. (2023)
[6] J.P. Knauer et al, Bulletin American Physical Society, Invited Presentation NI02.00002, (2022)
This material is based upon work supported by the Department of Energy Office of Fusion Energy Sciences under award DE-SC0022132, the National Nuclear Security Administration under Award Numbers DE-NA0003856, DE-NA0003868, the University of Rochester, and the New York State Energy Research and Development Authority. In collaboration with the LLE Experimental and Theory Divisions, the OMEGA facility team, the LLE Target Fabrication group, the LLE Cryogenic and Tritium group, the General Atomics target fabrication group and the HEDP Division at the MIT-PFSC.
