Here is a list of recent atomic data and models useful for astrophysics and fusion. Most recent first.
New atomic data for modelling photo-ionization (MNRAS)
In this paper we provide an extensive set of photo-ionization cross sections, most of them calculated by Nigel Badnell and others, but with some additions. The cross-sections are level-resolved which are needed for proper modelling, and are consistent with version 11 of the CHIANTI database. I also modified the CHIANTI IDL programs to calculate equilibrium for photo-ionized plasma.
New identifications and revised energies for many high-temperature ions using solar flares observed by Hinode EIS (MNRAS, 2025)
In this paper I review all the flare lines in the Hinode EIS spectra, confirming for the first time previous identifications based on Skylab for several lines (with modelling), and identifying for the first time several new lines never observed. Discrepancies in the experimental energies in CHIANTI and NIST have been found. Some have been resolved, but other not, requiring additional studies.
New identifications and level energies obtained from near-infrared observations (ApJ, 2025, in press)
In this work we revise previous energies we had in CHIANTI for two ions, Fe X and Si XI, using new air-borne observations and re-analysing older SOHO/SUMER data, where I found inconsistencies in previous work.
Dielectronic recombination of iron M-shell ions: Fe8+ and Fe7+ (MNRAS, 2025)
As a further tribute to Nigel Badnell, we completed this work under the guidance of Prof. P.J. Storey.
This work was part of the last UK APAP network grant, with Badnell as PI and Del Zanna G. as co-I.
Details are in 10.1093/mnras/staf1456 while we made the data available on ZENODO at
New atomic data for modelling the solar UV with radiative transfer calculations (MNRAS, 2025)
All radiative transfer codes we have looked at use in most cases very old approximate atomic data and incorrectly treat the radiative recombination. In this paper (DOI: 10.1093/mnras/staf1330) we show that with improved atomic modelling the UV continuum lowers by an order of magnitude, solving a very long-standing problem in astrophysics. The large set of new atomic data are provided in a new format I developed and are available on ZENODO at (https://doi.org/10.5281/zenodo.16679094)
Resonant photoexcitation in EUV lines (MNRAS, 2025)
The theory of this process is revised and a set of IDL codes with several assumptions have been developed. The comparisons with earlier models and with observations are excellent. The details are in this long paper which was four years in the making, DOI: 10.1093/mnras/staf1401
The codes are the first of their kind ever publicly available and are a modification of the CHIANTI programs. They are available on GitHub at github.com/chianti-vip/IDL
H, He-like recombination spectra VI: quadrupole l-changing collisions (MNRAS, 2025)
As a further tribute to the legacy of Nigel Badnell we finished this work.
See DOI: 10.1093/mnras/staf608
A new database of Electron-Impact Excitation Cross-Sections and rates (ATOMS, 2025) – a tribute to Nigel Badnell
The 20+ year contributions of the UK APAP (apap-network.org) led by Nigel Badnell came to an end when he passed away in 2024
To honour him and keep his legacy I collected all the EIE cross-section (collision strengths) and using the last version of a program written by Nigel I created bin-averaged values for all the sequence work, see DOI: 10.3390/atoms13050044. As several mistakes in the published effective collision strengths on the APAP web site and ADAS, I recalculated them for most of then sequences. The work was carried out over several months for free for posterity. The full dataset and all the associated codes used for the calculations are available on ZENODO (DOI:10.5281/zenodo.14946145) at https://zenodo.org/records/14946146. This is an unique dataset in atomic physics.
Nigel R. Badnell RIP (2024)
see the obituary I wrote in ATOMS: https://doi.org/10.3390/atoms13060055
New reduced atomic models for large-scale computations: Fe XIII near-infrared lines (Del Zanna G., Supriya Hebbur Dayananda, MNRAS, 2025)
New reduced atomic models for the near-infrared Fe XIII lines are presented. They are useful for either large spectro-polarimetric modelling (by selecting J-resolved states) or for just modelling line intensities (merging states). Details are in the paper, DOI: 10.1093/mnras/staf274.
The CHIANTI-format models developed and the equivalent one in P-CORONA format are available on ZENODO at https:// doi.org/ 10.5281/ zenodo.13988111 .
New atomic data and modelling for CHIANTI version 11
After a long time, we released advanced models to calculate ionization equilibrium for stellar transitions regions, adding density-dependent effects and charge transfer. Details are here DOI: 10.3847/1538-4357/ad6765 whilst the CHIANTI programs I wrote in collaboration with Roger Dufresne are available on GitHub. The new atomic data are available within the CHIANTI web pages and on SolarSoft.
- Atomic data for satellite lines from Fe XVI. Del Zanna, Badnell and Storey 2024, MNRAS https://arxiv.org/abs/2405.01274
The MaGIXS 2021 sounding rocket produced the first ever spectral-imaging data of the solar corona in the X-rays. Comparisons with a CHIANTI model spectrum indicated a missing flux of about a factor of 2 around the strongest X-ray line, Fe XVII at 15 Å, see Savage+2023, https://iopscience.iop.org/article/10.3847/1538-4357/acbb58/pdf .After running several atomic calculations, this difficult problem has been solved, as such increase at 2 MK was obtained by adding a large-scale model for Fe XVI satellite lines. This issue is currently very relevant for astrophysics: the Fe XVII lines are the most studied in the X-rays, with well over 100 recent publications discussing discrepancies between theory and laboratory/astrophysical spectra.
The atomic data are available at ZENODO at https://doi.org/10.5281/zenodo.11474529
whilst the programs are at https://github.com/CHIANTI-VIP/IDL/ - The CHIANTI v11.0 data files (test version) are available here: https://chianti-vip.com/database/v11.0
Page updated on 13 July 2024