[en] A recent transport model for partially coherent light is reexamined. In its original formulation, this model involves a transport equation for the one-photon Wigner function with nonlocal source and loss terms. We show here that under suitable approximations this equation can be reformulated in a compact form involving the Moyal star product and the related symmetric and antisymmetric brackets. This formulation provides a general framework for the establishment of opacity models accounting for radiation coherence. An investigation of anomalous dispersion in magnetic fusion plasma conditions is reported as an illustration of the model. - Highlights: • We model atomic line radiation transport within a quantum phase space approach. • Analogies and differences with Hamiltonian optics are illustrated. • Applications to hydrogen lines in optically thick divertor plasmas are performed. • These plasmas can be strongly affected by anomalous dispersion

[en] A new table of Stark–Zeeman line shapes is provided for plasma diagnostics in the framework of magnetic fusion research. Spectral profiles of Dα, Dβ, Dγ, Dδ, and Dε have been calculated using computer simulations in conditions relevant to tokamak edge and divertor plasmas. After a brief presentation of the calculation method, we propose an interpolation formula and we give a routine for diagnostic applications. Analyses of experimental and synthetic spectra are performed as an illustration. - Highlights: • A new table of Stark–Zeeman line shapes is provided for plasma diagnostics. • The calculations were performed using a computer simulation technique, which serves as a reference in the elaboration of Stark broadening models. • Analyses of experimental and synthetic spectra in tokamak divertor plasma conditions are performed as an illustration.

[en] Spectral profiles of the Dγ line have been calculated in magnetic fusion plasma conditions for diagnostic purposes. This paper reports on the elaboration of a table devoted to spectroscopic applications in tokamak divertors. An overview of the method, together with the physics underlying the broadening of spectral lines, is given. A special emphasis is put on the role of the simultaneous action of the Stark and Zeeman effects. - Highlights: • We present new calculations of Stark–Zeeman line shapes for magnetic fusion plasma diagnostics. • The sensitivity of spectra to the electron density is examined. • Applications to synthetic diagnostics in a virtual plasma background are discussed

[en] We revisit the formalism involved in atomic spectroscopy modeling under the assumption that the photon has a finite mass. Starting from the Proca Lagrangian, we build a Hamiltonian suitable for the calculation of line shapes and intensities. Two consequences of finite photon mass are: 1) a dispersion of electromagnetic waves propagating in free space; 2) the occurrence of a longitudinal polarization state. We illustrate these effects by addressing the spontaneous emission of a massive photon by an excited atom. The Einstein A coefficient and the power spectrum are calculated as an example. If the photon has a finite mass, deviations to standard formulas are showed to occur at energies comparable to the mass energy. A discussion based on the current upper bound estimates for the photon mass is done. (author)

[en] A kinetic photon transport model that accounts for spatial coherence is applied to line radiation in optically thick plasmas. It is shown that the photon emission and absorption processes are delocalized in space, which alters the global plasma opacity to spectral lines. Based on this analysis, we demonstrate that spectral profiles and escape factors can be much larger than expected from usual formulas.

[en] Spectral line shapes and intensities are used for obtaining information on the various regions of magnetic fusion devices. Emission from low principal quantum numbers of hydrogen isotopes is analyzed for understanding the complex recycling mechanism. Lines emitted from high principal quantum numbers of hydrogen and helium are dominated by Stark effect, allowing an electronic density diagnostic in the divertor. Intensities of lines emitted by impurities are fitted for a better knowledge of ion transport in the confined plasma

[en] The nonlinear coupling of Langmuir, ion sound and electromagnetic waves can create wave collapse conditions in a plasma, and modify the line shapes emitted by hydrogen atoms. Such conditions may appear in the presence of a strong source of energy, and create numerous regions where wave packets localize and the plasma density is decreased. We use a model of envelope solitons for the electric field acting on the emitter, and calculate the dipole autocorrelation function and the line shape with a numerical simulation. We investigate the role of the frequency of wave packets, and propose an approach retaining a dispersion relation ω(k). (paper)

[en] The nonlinear interaction of waves can change the structural and radiative properties of plasmas. We describe the main features of a fully ionized unmagnetized plasma affected by strong Langmuir turbulence characterized by nonlinear wave collapse, and propose a simple model for evaluating the changes expected on a hydrogen line shape affected by such conditions. Our model is based on a stochastic renewal model using an exponential waiting time distribution and a half-normal probability density function for the electric-field magnitude of the turbulent wave packet. The first results obtained with a simulation calculation of the hydrogen ${\text{L}}_{\mathrm{\alpha <!--\; ??\; -->}}$ line show that strong Langmuir turbulence can provide an additional broadening to a Stark profile. (letter)

[en] We report calculations of hydrogen line shapes in tokamak edge plasma conditions. A special emphasis is put on the motional Stark effect that arises due to the electric field v-vector × B-vector present in the frame of reference of an atom moving at a velocity v-vector . The statistical repartition of the velocities results in a broadening of the lines, which can be significant if the upper level of the transition under consideration is high. Applications to Balmer lines are shown here

[en] We examine atomic line shapes in a magnetized hydrogen plasma. The Lorentz electric field v × B present in the emitters' frame of reference yields a perturbation of the atomic energy levels, which is commonly referred to as a ‘motional’ Stark effect. This effect results in a broadening of the lines owing to the statistical repartition of the atoms' velocities. We address this line broadening mechanism with numerical simulations. It is shown that Balmer line shapes can be affected at plasma conditions relevant to magnetic fusion experiments. An application to the diagnostic of an atomic temperature is suggested and discussed within a line width analysis. The possibility for a modification of the Inglis–Teller limit, which provides an estimate of the principal quantum number of the last resolved line in a series, is also discussed. (paper)