6 research outputs found
Increase of the Density, Temperature and Velocity of Plasma Jets driven by a Ring of High Energy Laser Beams
Supersonic plasma outflows driven by multi-beam, high-energy lasers, such as
Omega and NIF, have been and will be used as platforms for a variety of
laboratory astrophysics experiments. Here we propose a new way of launching
high density and high velocity, plasma jets using multiple intense laser beams
in a hollow ring formation. We show that such jets provide a more flexible and
versatile platform for future laboratory astrophysics experiments. Using high
resolution hydrodynamic simulations, we demonstrate that the collimated jets
can achieve much higher density, temperature and velocity when multiple laser
beams are focused to form a hollow ring pattern at the target, instead of
focused onto a single spot. We carried out simulations with different ring
radii and studied their effects on the jet properties. Implications for
laboratory collisionless shock experiments are discussed.Comment: 5 pages, 4 figures, Accepted to HED
Feasibility and Performance of the Staged Z-Pinch: A One-dimensional Study with FLASH and MACH2
Z-pinch platforms constitute a promising pathway to fusion energy research.
Here, we present a one-dimensional numerical study of the staged Z-pinch (SZP)
concept using the FLASH and MACH2 codes. We discuss the verification of the
codes using two analytical benchmarks that include Z-pinch-relevant physics,
building confidence on the codes' ability to model such experiments. Then,
FLASH is used to simulate two different SZP configurations: a xenon gas-puff
liner (SZP1*) and a silver solid liner (SZP2). The SZP2 results are compared
against previously published MACH2 results, and a new code-to-code comparison
on SZP1* is presented. Using an ideal equation of state and analytical
transport coefficients, FLASH yields a fuel convergence ratio (CR) of
approximately 39 and a mass-averaged fuel ion temperature slightly below 1 keV
for the SZP2 scheme, significantly lower than the full-physics MACH2
prediction. For the new SZP1* configuration, full-physics FLASH simulations
furnish large and inherently unstable CRs (> 300), but achieve fuel ion
temperatures of many keV. While MACH2 also predicts high temperatures, the fuel
stagnates at a smaller CR. The integrated code-to-code comparison reveals how
magnetic insulation, heat conduction, and radiation transport affect platform
performance and the feasibility of the SZP concept