Stark broadening of high principal quantum number hydrogen Balmer lines in low-density laboratory plasmas

Abstract

We present results for Stark broadening of high principal quantum number (up to n=15 ) Balmer lines, using an analytical (the "standard theory") approach and two independently developed computer simulation methods. The line shapes are calculated for several sets of plasma parameters, applicable to radio-frequency discharge (N(e) approximately 10(13) cm(-3)) and magnetic fusion (N(e) approximately 10(15) cm(-3)) experiments. Comparisons of the calculated line profiles to the experimental data show a very good agreement. Density and temperature dependences of the linewidths, as well as relative contributions of different Stark-broadening mechanisms, are analyzed. It is seen that the standard theory of line broadening is sufficiently accurate for the entire set of plasma conditions and spectral transitions considered here, while an alternative theory ("advanced generalized theory") is shown to be inadequate for the higher-density region. A discussion of possible reasons for this disagreement is given.

Plasma line broadening and computer simulations: A mini-review

“…Nevertheless, in several cases accurate and detailed calculations are yet impossible without CSMs. As examples we note that CSM results are widely used as plasma diagnostic tables [36], sought as a definite arbitrator in comparing competing theories [37,38], applied in situations when the Stark line shapes are significantly altered by either the fine-structure effects [29] or magnetic field [39,40], employed for studying effects of correlations in plasma-particle motion on line shapes [33,34,41], and used for the analysis of line-shape asymmetries [42,43]; this list is far from being exhaustive.…”

A table of Balmer γ line shapes for the diagnostic of magnetic fusion plasmas

“…At such high-density plasma conditions, the spectral lines with a high principal quantum number n (say, of the order of 10) are affected by Stark broadening and can be used as a probe of the electron density (passive spectroscopy), e.g. [2][3][4][5][6][7][8][9][10][11]. An analysis of lines with a moderate quantum number such as Dγ (n¼ 5) is more intricate, because the Stark broadening can be of the same order as the Doppler broadening and it can be affected by ion dynamics.…”

H-β Line in a Corona Helium Plasma: A Multi-Code Line Shape Comparison

“…More details can be found in Reference [4] and the references therein. SimU is well described in References [5,6]. The three models are PPP [7], QC_FFM (Reference [8] and the references therein) and ZEST.…”