No Arabic abstract
We report on the results of the 10th Non-LTE code comparison workshop, which was held at the University of San Diego campus November 28 through December 1, 2017. Non-equilibrium collisional-radiative models predict the electronic state populations and attendant emission and absorption characteristics of hot, dense matter and are used to help design and diagnose high-energy-density experiments. At this workshop, fifteen codes from eleven institutions contributed results for steady-state and time-dependent neon, aluminum, silicon, and chlorine cases relevant to a variety of high-density experimental and radiation-driven astrophysical systems. This report focuses on differences in the predictions from codes with different internal structure, completeness, density effects, and rate fidelity and the impact of those differences on hot, dense plasma diagnostics.
We present the results of the first Charged-Particle Transport Coefficient Code Comparison Workshop, which was held in Albuquerque, NM October 4-6, 2016. In this first workshop, scientists from eight institutions and four countries gathered to compare calculations of transport coefficients including thermal and electrical conduction, electron-ion coupling, inter-ion diffusion, ion viscosity, and charged particle stopping powers. Here, we give general background on Coulomb coupling and computational expense, review where some transport coefficients appear in hydrodynamic equations, and present the submitted data. Large variations are found when either the relevant Coulomb coupling parameter is large or computational expense causes difficulties. Understanding the general accuracy and uncertainty associated with such transport coefficients is important for quantifying errors in hydrodynamic simulations of inertial confinement fusion and high-energy density experiments.
Contents: 1. Finestructure Constants at the Planck Scale from Multiple Point Principle (D.L.Bennett, L.V. Laperashvili and H.B. Nielsen) 2. Random Dynamics in Starting Levels (D. Bennett, A. Kleppe in H.B. Nielsen), 3. Families of Quarks and Leptons and Their Mass Matrices from the Approach Unifying Spins and Charges: Prediction for the Fourth Family (G. Bregar, M. Breskvar, D. Lukman and N.S. Mankoc Borstnik) 4. Fermion-Fermion and Boson-Boson Amplitudes: Surprising Similarities (V.V. Dvoeglazov) 5. Antisymmetric Tensor Fields, 4-Vector Fields, Indefinite Metrics and Normalization (V.V. Dvoeglazov) 6. Quantum Gates and Quantum Algorithms with Clifford Algebra Technique (M. Gregoric and N.S. Mankoc Borstnik) 7. From the Starting Lagrange Density to the Effective Fields for Spinors in the Approach Unifying Spins and Charges (N.S. Mankoc Borstnik) 8. New Generations of Particles in the Universe (M.Yu. Khlopov) 9. A Subversive View of Modern Physics (R. Mirman) 10. Mass Spectra are Inherent in Geometry: an Analysis Using the Only Conformal Group Allowing a Universe (R. Mirman) 11. Complex Action, Prearrangement for Future and Higgs Broadening (H.B. Nielsen and M. Ninomiya) 12. Discussion on Dark Matter Candidates from the Approach Unifying Spins and Charges (G. Bregar and N.S. Mankoc Borstnik) 13. Discussion Section Summary on Dark Matter Particle Properties (M.Yu. Khlopov and N.S. Mankoc Borstnik)
We describe PyRaTE, a new, non-local thermodynamic equilibrium (non-LTE) line radiative transfer code developed specifically for post-processing astrochemical simulations. Population densities are estimated using the escape probability method. When computing the escape probability, the optical depth is calculated towards all directions with density, molecular abundance, temperature and velocity variations all taken into account. A very easy-to-use interface, capable of importing data from simulations outputs performed with all major astrophysical codes, is also developed. The code is written in Python using an `embarrassingly parallel strategy and can handle all geometries and projection angles. We benchmark the code by comparing our results with those from RADEX (van der Tak et al. 2007) and against analytical solutions and present case studies using hydrochemical simulations. The code is available on GitHub (https://github.com/ArisTr/PyRaTE).
Code reviews are popular in both industrial and open source projects. The benefits of code reviews are widely recognized and include better code quality and lower likelihood of introducing bugs. However, since code review is a manual activity it comes at the cost of spending developers time on reviewing their teammates code. Our goal is to make the first step towards partially automating the code review process, thus, possibly reducing the manual costs associated with it. We focus on both the contributor and the reviewer sides of the process, by training two different Deep Learning architectures. The first one learns code changes performed by developers during real code review activities, thus providing the contributor with a revised version of her code implementing code transformations usually recommended during code review before the code is even submitted for review. The second one automatically provides the reviewer commenting on a submitted code with the revised code implementing her comments expressed in natural language. The empirical evaluation of the two models shows that, on the contributor side, the trained model succeeds in replicating the code transformations applied during code reviews in up to 16% of cases. On the reviewer side, the model can correctly implement a comment provided in natural language in up to 31% of cases. While these results are encouraging, more research is needed to make these models usable by developers.
In this paper, we give a review of three hohlraum geometries, including cylindrical, octahedral and six-cylinder-port hohlraums, in inertial confinement fusion (ICF) mainly from theoretical side. Every hohlraum has its own strengths and weaknesses. Although there is a problem of drive asymmetry in the cylindrical hohlraums due to some non-ideal factors, the success of ignition is still possible if more laser energy is available beyond the US National Ignition Facility (NIF) in the future. Octahedral hohlraums can provide the high symmetry flux on capsule. However, octahedral hohlraums suffer from several problems due to the complicated three-dimensional plasma conditions inside. And up to now, there is no one target design with the octahedral hohlraums in which each problem can be solved at the same time. Six-cylinder-port hohlraums combine the merits in theory of both cylindrical and octahedral hohlraums to a certain extent. We introduce a target design with good performance by using the six-cylinder-port hohlraums, in which the key issues of concern, such as laser energy, drive symmetry, and laser plasma interaction (LPI), etc, are all balanced.