Spectra of dense pure hydrogen plasma in Balmer area

Evidence of a first-order phase transition to metallic hydrogen

“…At lower pressures and higher temperatures it is predicted to have a critical point so that for pressures below the critical pressure, the dissociative transition is continuous. The PPT is a Mott transition to a metallic liquid, whereas, for example, a low to modest density of hydrogen can electrically conduct as a plasma at very high temperatures [23] but is not a metal! A common IMT in an ordered system involves overlapping energy bands; in disordered systems there are mobility bands.…”

The Application of the Cut-Off Coulomb Model Potential for the Calculation of Bound-Bound State Transitions

“…The next step towards the application of the model results is a calculation of the oscillator strength values for the plasma parameters denoted as "short", with N e = 1.5 × 10 19 cm −3 , T = 23, 000 K and "long" pulse, with N e = 6.5 × 10 18 cm −3 , T = 18, 000 K from [14]. The radius r i , given by Equation (5), Wigner-Seitz and cut-off radius as well as atom concentrations given by the Saha equation are r i = 51.0655 a.u., r s;i = 47.5339 a.u., r c = 44.9907 a.u., N a = 1.9 × 10 19 cm −3 for short and r i = 68.6260 a.u., r s;i = 62.8149 a.u., r c = 60.4062 a.u., N a = 3.4 × 10 19 cm −3 for long pulse.…”

“…Our future plan is to include broadening processes and make it possible to directly compare data with the experimental ones (e.g., the data from [14]). In continuation, some of the bound-bound theoretical aspects are shown.…”

“…Table 1. The oscillator strength values for the "short", Ne = 1.5 × 10 19 cm −3 , T = 23, 000 K, and "long" pulse, Ne = 6.5 × 10 18 cm −3 , T = 18, 000 K, from [14], as well as a theoretical hydrogen case calculated by code from [18], and NIST spectral database values [30].…”

“…The neutral hydrogen concentration from experimental data from [14] is used, and, since the result presented here is in the area where the Saha equation is valid, the neutral concentrations using the Saha equation with the ionization potential correction is possible. Since this is related to the further step, bound level broadening mechanism, the procedure was not elaborated here.…”