Optimization of soft x-ray emission from stagnating compact toroidal plasmas: A computational study

Computational simulations aimed at optimizing the high-energy, high-power, multikilovolt electromagnetic radiation emitted by a rapidly moving compact toroidal (CT) plasma which stagnates against a stationary “wall” are performed for argon, krypton, and xenon plasmas over a range of CT parameters. CT kinetic energies vary from 2–10 MJ, impact speeds vary from 50–200 cm/μs, and CT masses vary from 5–11 mg. It is found that a 2 MJ Ar CT optimally emits 1–1.5 MJ of essentially K-line radiation (>3 keV) for impact speeds of about 60–90 cm/μs; a 10 MJ Kr CT optimally emits about 1 MJ of essentially K-line radiation (>12.5 keV) for impact speed of about 135 cm/μs; and a 10 MJ Xe CT optimally emits about 3 MJ of essentially L-line radiation (>5 keV), about 0.5 MJ of continuum radiation above 10 keV, and about 0.1 MJ of continuum radiation above 20 keV, all also for impact speed of about 135 cm/μs. Pulse widths vary for the above optima from 7 ns at 135 cm/μs to 30 ns at 60 cm/μs.