Spectroscopy of Hydrogenic Spectral Lines in Plasmas: Review of the Latest Analytical Progresses

Broadening of hydrogenic spectral lines is an important tool in spectroscopic diagnostics of various laboratory and astrophysical plasmas. We review recent analytical advances in five areas. First, we review a new method for spectroscopic diagnostics of tokamak edge plasmas based on a peculiar Stark broadening of hydrogen or deuterium spectral lines emitted by the injected neutral beam. Second, we review the analytical solution for the magnetic-field-caused narrowing of hydrogenic spectral lines under a circularly polarized electromagnetic wave. Third, we review analytical results concerning the Stark-Zeeman broadening of the Lyman-alpha line in plasmas. Forth, we review the effect of helical trajectories of electrons in strongly magnetized plasmas on the width of hydrogen/deuterium spectral lines. Fifth, we review recent analytical advances in the area of the intra-Stark spectroscopy: three different new methods, based on the emergent phenomenon of the Langmuir-wave-caused structures (“L-dips”) in the line profiles, for measuring super-strong magnetic fields of the GigaGauss range developing during relativistic laser-plasma interactions. We also review the rich physics behind the L-dips phenomenon – because there was a confusion in the literature in this regard.