The CHIANTI spectral code consists of an atomic database and a suite of computer programs to calculate the optically thin spectrum of astrophysical objects and carry out spectroscopic plasma diagnostics. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, and ionization and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7 has been released, which includes several new ions, significant updates to existing ions, as well as Chianti-Py, the implementation of CHIANTI software in the Python programming language. All data and programs are freely available at http://www.chiantidatabase.org, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net.

/pdf/chianti-an-atomic-database-for-emission-lines-xii-version-7-4y5jdtauvc.pdf

Chianti—an atomic database for emission lines. xii. version 7 of the database

The current status of bound state quantum electrodynamics calculations of transition energies for few-electron ions is reviewed. Evaluation of one and two body QED correction is presented, as well as methods to evaluate many-body effects that cannot beevaluated with present-day QED calculations. Experimental methods, their evolution over time, as well as progress in accuracy are presented. A detailed, quantitative, comparison between theory and experiment is presented for transition energies in few-electron ions. In particular the impact of the nuclear size correction on the quality of QED tests as a function of the atomic number is discussed.The cases of hyperfine transition energies and of bound-electron Land{e} $g$-factor are also considered.

QED tests with highly charged ions

Radiation emitted from silicon beams at 35, 38 and 45 MeV excited by passage through thin carbon foils has been studied in the range 3-9 AA using a curved-crystal X-ray spectrometer. More than 100 lines have been observed, of which only one quarter had been observed or predicted from solar or laboratory plasma spectra. Most of the previously unobserved lines may be attributed to satellites of H- and He-like transitions arising in three- and four-electron Si ions. The lifetime of the Si XIII 23P1 state has been measured, and a preliminary experimental value of 6.5+or-1.3 ps obtained.

https://iopscience.iop.org/article/10.1088/0022-3700/12/10/013/pdf

The X-ray spectra of H-like, He-like and Li-like silicon ions after foil excitation

This research was supported in part by Projects No. PEstOE/FIS/UI0303/2011 and No. PTDC/FIS/117606/2010, and by research center Grant No. UID/FIS/04559/2013 (LIB-Phys), from FCT/MCTES/PIDDAC, Portugal. We acknowledge partial support from NIST (P.I.), from PESSOA Huber Curien Program No. 38028UD, and PAUILF Program No. 2017-C08. P.A., J.M., and M.G. acknowledge support from FCT under Contracts No. SFRH/BPD/92329/2013, No. SFRH/BD/52332/2013, and No. SFRH/BPD/92455/2013, respectively. Laboratoire Kastler Brossel (LKB) is "Unite Mixte de Recherche de Sorbonne Universite, de ENS-PSL Research University, du College de France et du CNRS No. 8552." P.I. is a member of the Allianz Program of the Helmholtz Association, Contract No. EMMI HA-216 "Extremes of Density and Temperature: Cosmic Matter in the Laboratory." The SIMPA ECRIS has been financed by grants from CNRS, MESR, and University Pierre and Marie Curie (now Sorbonne Universite). The experiment has been supported by BNM Grant No. 0130002 and ANR Grant No. ANR-06-BLAN-0223. We wish to thank Jean-Paul Desclaux for his help improving the MCDFGME code, and Dr. Martino Trassinelli (INSP) for valuable discussions and his help during early stages of the experiment.

/pdf/high-precision-measurements-of-n-2-n-1-transition-energies-vsbw5spq2p.pdf

High-precision measurements of n = 2 → n = 1 transition energies and level widths in He- and Be- like Argon Ions

QED tests with highly-charged ions

Besides the prompt x-ray emission of Ar-ions, the metastable decay of the heliumlike3
P
2- and the lithiumlike4
P
5/2-levels of highly ionized Ar16+ and Ar15+ atoms has been observed in a foil-excited beam using a flat-crystal spectrometer. Due to the highx-ray energy resolution of the spectrometer the two3
P
2 →1
S
0 and4
P
5/2 →2
S
1/2 transitions could be resolved. The experiment yielded (3128 ±2) eV for the3P2 → and (3091 ± 2)eV for the4
P
5/2 →2
S
1/2 transition energy respectively. Using a time of flight technique the lifetimes of the3
P
2- and the4
P
5/2-states were determined to be (1.44 ±0.09)ns and (0.66 ± 0.05) ns.

High resolution spectroscopy of prompt and metastable decaying levels in highly ionized argon, especially of the metastable 3 P 2 -state of Ar 16+ and the 4 P 5/2 -state of Ar 15+

D. Liesen

Papers

High resolution spectroscopy of prompt and metastable decaying levels in highly ionized argon, especially of the metastable 3 P 2 -state of Ar 16+ and the 4 P 5/2 -state of Ar 15+