High-resolution measurements of Cl15+ line shifts in hot, solid-density plasmas

Abstract

The shifts of the 1s3p 1 P 1 → 1s 2 1 S 0 He-β transition of Cl 15+ were measured in hot (≥ 600 eV), dense (1-2 g/cc) plasmas generated by a 66-151 J short-pulse laser beam at the Orion laser facility. The sub-picosecond laser beam irradiated optically thin, KCl microdot targets buried in layers of plastic. The measured red shifts ranged from 4.8 ± 1.1 eV for unshocked to 5.9 ± 1.2 eV for shocked targets. These values are significantly smaller than recent predictions from a self-consistent field ion-sphere model.

Analytical approach to level delocalization and line shifts in finite temperature dense plasmas

“…Figure 2 compares the present MCDF-SCFTIS model calculations (red and green crosses, connected with dashed lines) with the measurements (open and solid circles) of the He β line shifts of Cl 15 + of [29]. As can be seen the present MCDF-SCFTIS calculations are in excellent agreement with the measurements.…”

“…Note, that the average atom ISM does not include multi configuration and intermediate coupling effects as does the present MCDF-SCFTIS model, more details are described in [28]. Within the large experimental error bars, we can therefore confirm the [29]. Also shown in the figure our present results employing the analytical model of [36] (4 th -order blue crosses, 2 nd -order solid blue and red lines) and the average atom ion sphere model ISM from [30] (pink solid circles, connected with solid line).…”

“…It is therefore well suited to compare simulations with the data that are obtained in the overwhelming number of cases by spectroscopic methods. Recent measurements have questioned our understanding in the precision of the Multi-Configuration-Dirac-Fock Self-Consistent Finite Temperature Ion Sphere model MCDF-SCFTIS [7,27,28]: it was claimed [29] that measured line shift values are significantly smaller than predictions from the selfconsistent-field ion-sphere model. However, later numerical analysis showed [30,31,32,33] that excellent agreement with the finite temperature ion sphere model, the arbitrary perturbation potential method APPM [34], the analytical b-parameter potential method [32] and the data is obtained.…”

“…In this letter we report on a critical analysis of recent highresolution spectroscopic data on X-ray line shift measurements [29] and analytical approximations of numerical solutions. We develop a 4 th -order analytical approximation of the arbitrary perturbation potential method APPM [34] and demonstrate excellent agreement with the present MCDF -SCFTIS calculations and the data.…”

Measurement of n-resolved State-selective Charge Exchange in Ne(8,9)+ Collision with He and H2

“…More recently, significant progress in CX studies has been made with high-resolution X-ray microcalorimeters (Defay et al 2013;Fogle et al 2014;Seely et al 2017;Betancourt-Martinez et al 2018;Zhang et al 2019) and crystal spectrometers (Beiersdorfer et al 2005(Beiersdorfer et al , 2018(Beiersdorfer et al , 2019Lepson et al 2017). For instance, by measuring Lyβ/Lyα line ratios for X-ray emission in C 6+ -He electron capture at solar wind velocities, Defay et al (2013) clarified n = 3 capture being dominant, which later on was correctly reproduced by Cumbee et al (2017), while in a previous solar wind model Koutroumpa (2007) only assumed the dominant capture.…”