Investigation of magnetic flux transport and shock formation in a staged Z-pinch

Journal Article · Thu Oct 12 00:00:00 EDT 2017 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4997917· OSTI ID:1399176

Narkis, J. ; Rahman, H. U.; Wessel, F. J.; Beg, F. N.

Target preheating is an integral component of magnetized inertial fusion in reducing convergence ratio. In the staged Z-pinch concept, it is achieved via one or more shocks. Previous work [Narkis et al., Phys. Plasmas 23, 122706 (2016)] found that shock formation in the target occurred earlier in higher-Z liners due to faster flux transport to the target/liner interface. However, a corresponding increase in magnitude of magnetic pressure was not observed, and target implosion velocity (and therefore shock strength) remained unchanged. To investigate other means of increasing the magnitude of transported flux, a Korteweg-de Vries-Burgers equation from the 1-D single-fluid, resistive magnetohydrodynamic equations is obtained. Solutions to the nondispersive (i.e., Burgers) equation depend on nondimensional coefficients, whose dependence on liner density, temperature, etc., suggests an increase in target implosion velocity, and therefore shock strength, can be obtained by tailoring the mass of a single-liner gas puff to a double-liner configuration. In the selected test cases of 1-D simulated implosions of krypton on deuterium, the peak Mach number increased from ∼5 to ∼8. While a notable increase was seen, Mach numbers exceeding 10 (implosion velocities exceeding ∼25 cm/μs) are necessary for adequate shock preheating.

• Sponsoring Organization: USDOE
• Grant/Contract Number: AR0000569
• OSTI ID: 1399176
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Vol. 24 Journal Issue: 10; ISSN 1070-664X
• Publisher: American Institute of Physics
• Country of Publication: United States
• Language: English