Benchmarking multilevel, 2-D cylindrical radiation transport in a high energy density plasma environment

Apruzese, J. P.; Giuliani, J. L.; Hansen, Stephanie B.

doi:10.1016/j.hedp.2012.03.005

Cited by 7 publications

(2 citation statements)

References 25 publications

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“…A realistic multidimensional radiative transfer remains a significant computational challenge. A promising algorithm for 2-D transport along with benchmark calculations for an eight-level atomic model is described in [44].…”

Section: Current Research Areasmentioning

confidence: 99%

Radiation Transport in Z-Pinches

Apruzese

Giuliani

2015

IEEE Trans. Plasma Sci.

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Z-pinches, formed by passing large currents through wires or gas puffs, are the most powerful and energetic laboratory sources of X-rays. As higher current generators become available, Z-pinches incorporate increasingly larger masses of plasma and are nearly always optically thick to some or most of the photons that they produce. Understanding and modeling the transport of this radiation is an important element in attaining an overall picture of the physics of Z-pinches and in optimizing their properties for applications. This paper focuses on the aspects of radiation transport that are most relevant to the Z-pinch environment. The topics covered include: theory of radiation transport and its strengths and limitations, sources of opacity in Z-pinches, requirements for local thermodynamic equilibrium in the presence of opacity, transition to the blackbody limit, and Z-pinch experiments that demonstrate the effects of radiation transport.

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Section: Current Research Areasmentioning

confidence: 99%

Radiation Transport in Z-Pinches

Apruzese

Giuliani

2015

IEEE Trans. Plasma Sci.

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“…However, that paper does not involve the curve geometrical problems. In practice, many heat transfer and radiation hydrodynamic problems arise in complicated geometry instruments, which are more appropriately modeled by using curved geometric coordinate systems such as spherical and cylindrical coordinates for simulation convenience [17][18][19][20][21][22]. For example, in [18], a radiation hydrodynamics (RHD) code was developed in Cartesian, cylindrical, and spherical geometries to simulate ICF involved problems.…”

Section: Introductionmentioning

confidence: 99%

Asymptotic-Preserving Discrete Schemes for Non-Equilibrium Radiation Diffusion Problem in Spherical and Cylindrical Symmetrical Geometries

Xia¹,

Shen²,

Yuan³

2018

CICP

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We study the asymptotic-preserving fully discrete schemes for nonequilibrium radiation diffusion problem in spherical and cylindrical symmetric geometry. The research is based on two-temperature models with Larsen's flux-limited diffusion operators. Finite volume spatially discrete schemes are developed to circumvent the singularity at the origin and the polar axis and assure local conservation. Asymmetric second order accurate spatial approximation is utilized instead of the traditional first order one for boundary flux-limiters to consummate the schemes with higher order global consistency errors. The harmonic average approach in spherical geometry is analyzed, and its second order accuracy is demonstrated. By formal analysis, we prove these schemes and their corresponding fully discrete schemes with implicitly balanced and linearly implicit time evolutions have first order asymptoticpreserving properties. By designing associated manufactured solutions and reference solutions, we verify the desired performance of the fully discrete schemes with numerical tests, which illustrates quantitatively they are first order asymptotic-preserving and basically second order accurate, hence competent for simulations of both equilibrium and non-equilibrium radiation diffusion problems.

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Effective versus ion thermal temperatures in the Weizmann Ne Z-pinch: Modeling and stagnation physics

et al. 2014

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The difference between the ion thermal and effective temperatures is investigated through simulations of the Ne gas puff z-pinch reported by Kroupp et al. [Phys. Rev. Lett. 107, 105001 (2011)]. Calculations are performed using a 2D, radiation-magnetohydrodynamic code with Tabular Collisional-Radiative Equilibrium, namely Mach2-TCRE [Thornhill et al., Phys. Plasmas 8, 3480 (2001)]. The extensive data set of imaging and K-shell spectroscopy from the experiments provides a challenging validation test for z-pinch simulations. Synthetic visible images of the implosion phase match the observed large scale structure if the breakdown occurs at the density corresponding to the Paschen minimum. At the beginning of stagnation (−4 ns), computed plasma conditions change rapidly showing a rising electron density and a peak in the ion thermal temperature of ∼1.8 keV. This is larger than the ion thermal temperature (<400 eV) inferred from the experiment. By the time of peak K-shell power (0 ns), the calculated electron density is similar to the data and the electron and ion thermal temperatures are equilibrated, as is observed. Effective ion temperatures are obtained from calculated emission line widths accounting for thermal broadening and Doppler velocity shifts. The observed, large effective ion temperatures (∼4 keV) early in the stagnation of this Ne pinch can be explained solely as a combination of compressional ion heating and steep radial velocity gradients near the axis. Approximations in the modeling are discussed in regard to the higher ion thermal temperature and lower electron density early in the stagnation compared to the experimental results.

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Benchmarking multilevel, 2-D cylindrical radiation transport in a high energy density plasma environment

Cited by 7 publications

References 25 publications

Radiation Transport in Z-Pinches

Radiation Transport in Z-Pinches

Asymptotic-Preserving Discrete Schemes for Non-Equilibrium Radiation Diffusion Problem in Spherical and Cylindrical Symmetrical Geometries

Effective versus ion thermal temperatures in the Weizmann Ne Z-pinch: Modeling and stagnation physics

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