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We consider three- and four-level atomic lasers that are either incoherently (unidirectionally) or coherently (bidirectionally) pumped, the single-mode cavity being resonant with the laser transition. The intra-cavity Fano factor and the…

Quantum Physics · Physics 2009-11-07 Laurent Chusseau , Jacques Arnaud , Fabrice Philippe

High-resolution tunable laser spectroscopy is used to measure time-resolved absorption spectra for ten neutral uranium transitions and six singly-ionized transitions in a laser produced plasma. Spectral lineshapes are analyzed to determine…

Electron conduction opacities are one of the main physics inputs for the calculation of low- and intermediate-mass stellar models, and a critical question is how to bridge calculations for moderate and strong degeneracy, which are…

Solar and Stellar Astrophysics · Physics 2021-10-27 Santi Cassisi , Alexander Y. Potekhin , Maurizio Salaris , Adriano Pietrinferni

Radiative emission lines from nitrogen and its ions are often observed in nebulae spectra, where the N$^{2+}$ abundance can be inferred from lines of the 2p4f configuration. In addition, intensity ratios between lines of the 2p3p -- 2p3s…

Atomic Physics · Physics 2015-03-17 Xiaozhi Shen , Jiguang Li , Per Jönsson , Jianguo Wang

We introduce a covariant canonical quantization for a particle in curved spacetime that tracks operator-ordering ambiguities. Parameterizing spatial and temporal ordering, we derive a Hermitian Hamiltonian with leading quantum-relativistic…

General Relativity and Quantum Cosmology · Physics 2025-09-01 Karol Sajnok , Kacper Dębski

We study two different physical scenarios of thermonuclear reactions in stellar plasmas proceeding through a narrow resonance at low energy or through the low energy wing of a wide resonance at high energy. Correspondingly, we derive two…

Nuclear Theory · Physics 2009-11-10 F. Ferro , A. Lavagno , P. Quarati

There has been a growing request from the X-ray astronomy community for a quantitative estimate of systematic uncertainties originating from the atomic data used in plasma codes. Though there have been several studies looking into atomic…

We consider a family of random matrix ensembles (RME) invariant under similarity transformations and described by the probability density $P({\bf H})= \exp[-{\rm Tr}V({\bf H})]$. Dyson's mean field theory (MFT) of the corresponding plasma…

Condensed Matter · Physics 2009-10-28 C. M. Canali

For atoms embedded in dense plasma, the plasma screening effects will greatly alter their structure and dynamics, and then determine the radiation transport properties of the plasma. In the present work, a new statistical model is proposed…

Plasma Physics · Physics 2020-11-25 Fuyang Zhou , Yizhi Qu , Junwen Gao , Yulong Ma , Yong Wu , Jianguo Wang

We use a Monte Carlo simulation to calculate the spectra of mildly relativistic thermal plasmas in pair balance. We use the exact integral expression for the electron-positron thermal annihilation spectrum, and provide accurate expressions…

Astrophysics · Physics 2009-10-22 J. G. Skibo , C. D. Dermer , R. Ramaty , J. M. McKinley

The optical properties of plasmas with high densities and medium temperatures are analyzed by the use of a free electron model with Fermi-Dirac statistics. For the present collisional plasma the frequency of electron-ion collision is very…

Instrumentation and Methods for Astrophysics · Physics 2018-09-05 Y. Ben-Aryeh

Context. The radiative energy balance in the solar chromosphere is dominated by strong spectral lines that are formed out of LTE. It is computationally prohibitive to solve the full equations of radiative transfer and statistical…

Solar and Stellar Astrophysics · Physics 2015-06-04 Mats Carlsson , Jorrit Leenaarts

Calculations of the opacity of hot, dense matter require models for plasma line broadening. However, the most general theories are too complex to calculate directly and some approximation is inevitably required. The most widely-used…

Plasma Physics · Physics 2020-10-05 R. A. Baggott , S. J. Rose , S. P. D. Mangles

We calculate the rates and lepton (l) invariant mass distributions for decays of the form 0^{-+}->l^+l^-\gamma, which are important radiative corrections to the purely leptonic decays 0^{-+}->l^+l^-. Our approach uses the loop diagrams…

High Energy Physics - Phenomenology · Physics 2009-10-31 Duane A. Dicus , Wayne W. Repko

Simplified analytic methods are frequently used to model the light curves of supernovae and other energetic transients and to extract physical quantities, such as the ejecta mass and amount of radioactive heating. The applicability and…

High Energy Astrophysical Phenomena · Physics 2019-10-02 David K. Khatami , Daniel N. Kasen

We investigate the effects of plasma interactions on resonance-enhanced fusion rates in stars. Starting from basic principles we derive an expression for the fusion rate that can serve as a basis for discussion of approximation schemes. The…

Solar and Stellar Astrophysics · Physics 2015-06-04 R. F. Sawyer

Rate coefficients for inelastic Na+H collisions are calculated for all transitions between the ten levels up to and including the ionic state (ion-pair production), namely Na(3s,3p,4s,3d,4p,5s,4d,4f,5p)+H(1s) and Na+ + H-. The calculations…

Solar and Stellar Astrophysics · Physics 2015-05-19 P. S. Barklem , A. K. Belyaev , A. S. Dickinson , F. X. Gadea

A few years ago, Kurzweil and Hazak developed the Configurationally Resolved Super-Transition-Arrays (CRSTA) method for the computation of hot-plasma radiative opacity. Their approach, based on a temporal integration, is an important…

Atomic Physics · Physics 2025-06-18 Jean-Christophe Pain

The calculation of the discrete atomistic energy of a crystal near the continuum limit encounters difficulties caused by the geometric discrepancy between the continuum region occupied by the body, and the discrete collection of lattice…

Mathematical Physics · Physics 2016-05-06 Phoebus Rosakis

The microphysical, kinetic properties of astrophysical plasmas near accreting compact objects are still poorly understood. For instance, in modern general-relativistic magnetohydrodynamic simulations, the relation between the temperature of…

High Energy Astrophysical Phenomena · Physics 2023-03-08 Claudio Meringolo , Alejandro Cruz-Osorio , Luciano Rezzolla , Sergio Servidio
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