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Non-equilibrium ionization (NEI) is a key process often times neglected when modeling astrophysical plasmas with thermodynamical timescales much shorter than the timescales for ionization and recombination. In this paper, we perform NEI…

Space Physics · Physics 2020-12-24 Marcus DuPont , Chengcai Shen , Nicholas A. Murphy

Astrophysical shocks or bursts from a photoionizing source can disturb the typical collisional plasma found in galactic interstellar media or the intergalactic medium. The spectrum emitted by this plasma contains diagnostics that have been…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Randall K. Smith , John P. Hughes

A balanced description of both static and dynamic correlations in electronic systems with nearly degenerate low-lying states presents a challenge for multi-configurational methods on classical computers. We present here a quantum algorithm…

This contribution deals with the modeling of collisional multicomponent magnetized plasmas in thermal and chemical nonequilibrium aiming at simulating and predicting magnetic reconnections in the chromosphere of the sun. We focus on the…

Numerical Analysis · Mathematics 2021-06-01 Quentin Wargnier , Sylvain Faure , Benjamin Graille , Thierry Magin , Marc Massot

We present a new formulation of the correlated electron-ion dynamics (CEID) scheme, which systematically improves Ehrenfest dynamics by including quantum fluctuations around the mean-field atomic trajectories. We show that the method can…

Materials Science · Physics 2007-12-13 L. Stella , M. Meister , A. J. Fisher , A. P. Horsfield

Impulsive nanoflares are expected to transiently heat the plasma confined in coronal loops to temperatures of the order of 10 MK. Such hot plasma is hardly detected in quiet and active regions, outside flares. During rapid and short heat…

Astrophysics · Physics 2009-11-13 Fabio Reale , Salvatore Orlando

At the free-electron laser FLASH, multiple ionization of neon atoms was quantitatively investigated at 93.0 eV and 90.5 eV photon energy. For ion charge states up to 6+, we compare the respective absolute photoionization yields with results…

Atomic Physics · Physics 2015-06-12 R Guichard , M Richter , J-M Rost , U Saalmann , A A Sorokin , K Tiedtke

A multigrid method is proposed for solving nonlinear eigenvalue problems by the finite element method. With this new scheme, solving nonlinear eigenvalue problem is decomposed to a series of solutions of linear boundary value problems on…

Numerical Analysis · Mathematics 2015-01-09 Hehu Xie

This paper presents eigensolution and non-modal analyses for immersed boundary methods (IBMs) based on volume penalization for the linear advection equation. This approach is used to analyze the behavior of flux reconstruction (FR)…

Numerical Analysis · Mathematics 2021-11-09 Jiaqing Kou , Aurelio Hurtado-de-Mendoza , Saumitra Joshi , Soledad Le Clainche , Esteban Ferrer

The finite element method (FEM) is a well-established numerical method for solving partial differential equations (PDEs). However, its mesh-based nature gives rise to substantial computational costs, especially for complex multiscale…

Computational Engineering, Finance, and Science · Computer Science 2025-06-24 Weihang Ouyang , Yeonjong Shin , Si-Wei Liu , Lu Lu

In this work we propose an efficient and accurate multi-scale optical simulation algorithm by applying a numerical version of slowly varying envelope approximation in FEM. Specifically, we employ the fast iterative method to quickly compute…

Optics · Physics 2024-12-03 Fan Xiao , Jingwei Wang , Zhongfei Xiong , Yuntian Chen

We propose an adaptive planewave method for eigenvalue problems in electronic structure calculations. The method combines a priori convergence rates and accurate a posteriori error estimates into an effective way of updating the energy…

Computational Physics · Physics 2021-07-30 Beilei Liu , Huajie Chen , Geneviève Dusson , Jun Fang , Xingyu Gao

We develop a numerical solver for radiative transfer problems based on the weighted essentially nonoscillatory (WENO) scheme modified with anti-diffusive flux corrections, in order to solve the temperature and ionization profiles around a…

Astrophysics · Physics 2008-11-26 Jing-Mei Qiu , Long-Long Feng , Chi-Wang Shu , Li-Zhi Fang

High-resolution non-ideal magnetohydrodynamical simulations of the turbulent magnetized ISM, powered by supernovae types Ia and II at Galactic rate, including self-gravity and non-equilibriuim ionization (NEI), taking into account the time…

Astrophysics of Galaxies · Physics 2015-05-14 Miguel A. de Avillez , Dieter Breitschwerdt

In this paper, a new type of multi-level correction scheme is proposed for solving eigenvalue problems by finite element method. With this new scheme, the accuracy of eigenpair approximations can be improved after each correction step which…

Numerical Analysis · Mathematics 2011-07-04 Qun Lin , Hehu Xie

In this paper, a hybrid quasi-static atomistic simulation method at finite temperature is developed, which combines the advantages of MD for thermal equilibrium and atomic-scale finite element method (AFEM) for efficient equilibration. Some…

Atomic Physics · Physics 2015-06-17 Ran Xu , Bin Liu

Iterative multiscale methods for electronic structure calculations offer several advantages for large-scale problems. Here we examine a nonlinear full approximation scheme (FAS) multigrid method for solving fixed potential and…

Materials Science · Physics 2007-05-23 Nimal Wijesekera , Guogang Feng , Thomas L. Beck

We present a new code, RCF("Radiative-Collisional code based on FAC"), which is used to simulate steady-state plasmas under non local thermodynamic equilibrium condition, especially photoinization dominated plasmas. RCF takes almost all of…

Atomic Physics · Physics 2015-06-24 Bo Han , Feilu Wang , David Salzmann , Gang Zhao

The method of increments and frozen natural orbital (MI-FNO) framework is introduced to help expedite the application of noisy, intermediate-scale quantum~(NISQ) devices for quantum chemistry simulations. The MI-FNO framework provides a…

In the molecular dynamics calculations for the free energy of ions and ionic molecules, we often encounter wet charged molecular systems where electrical neutrality condition is broken. This causes a problem in the evaluation of…

Biological Physics · Physics 2020-07-15 Ryo Urano , Wataru Shinoda , Noriyuki Yoshii , Susumu Okazaki