Professor Nigel Badnell

Physics

Publications

R-matrix electron-impact excitation data for the C-like iso-electronic sequence
Mao J, Badnell N R, Zanna G Del
Astronomy and Astrophysics Vol 634 (2020)
https://doi.org/10.1051/0004-6361/201936931
H-, He-like recombination spectra III. n-changing collisions in highly-excited Rydberg states and their impact on the radio, IR and optical recombination lines
Guzmán F, Chatzikos M, van Hoof P A M, Balser Dana S, Dehghanian M, Badnell N R, Ferland GJ
Monthly Notices of the Royal Astronomical Society Vol 486, pp. 1003–1018 (2019)
https://doi.org/10.1093/mnras/stz857
Uncertainties on atomic data. A case study : NIV
Del Zanna G, Fernández-Menchero L, Badnell N R
Monthly Notices of the Royal Astronomical Society Vol 484, pp. 4754-4759 (2019)
https://doi.org/10.1093/mnras/stz206
Dielectronic recombination of lanthanide and low ionization state tungsten ions : W13+ - W+
Preval S P, Badnell N R, O'Mullane M G
Journal of Physics B: Atomic, Molecular and Optical Physics Vol 52 (2018)
https://doi.org/10.1088/1361-6455/aaf3f4
Suppression of dielectronic recombination due to finite density effects II : analytical refinement and application to density dependent ionization balances and AGN broad line emission
Nikolić D, Gorczyca T W, Korista K T, Chatzikos M, Ferland G J, Guzmán F, van Hoof P A M, Williams R J R, Badnell N R
Astrophysical Journal, Supplement Series Vol 237 (2018)
https://doi.org/10.3847/1538-4365/aad3c5
Electron-ion recombination rate coefficients of Be-like 40Ca16+ 
Wang S X, Xu X, Huang Z K, Wen W Q, Wang H B, Khan N, Preval S P, Badnell N R, Schippers S, Mahmood S, Dou L J, Chuai X Y, Zhao D M, Zhu X L, Mao L J, Ma X M, Li J, Mao R S, Yuan Y J, Tang M T, Yin D Y, Yang J C, Ma X, Zhu L F
Astrophysical Journal Vol 862 (2018)
https://doi.org/10.3847/1538-4357/aacc69

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Professional activities

ICAMDATA 2010
Invited speaker
2010
UN IAEA (External organisation)
Advisor
2010
ICPEAC (External organisation)
Member
2009
Invited Speaker – ADAS Workshop (MPI Schloss Ringberg) and ADAS-EU Course (IPP Garching)
Invited speaker
2009

More professional activities

Projects

Atomic Process for Astrophysical Plasmas Network (UK APAP Network) 2017
Badnell, Nigel (Principal Investigator)
01-Jan-2018 - 30-Jan-2021
Industrial Case Account 2015 | Gahle, Daljeet Singh
O'Mullane, Martin (Principal Investigator) Badnell, Nigel (Co-investigator) Gahle, Daljeet Singh (Research Co-investigator)
01-Jan-2016 - 01-Jan-2021
Atomic Processes for Magnetic Fusion Plasmas
Badnell, Nigel (Principal Investigator) O'Mullane, Martin (Co-investigator)
"Magnetic fusion is under intense study through-out the world as a safe and clean energy source for the future.
Present day machines include JET in the UK and ASDEX in Germany, while the next step machine ITER is
currently under construction in France.

The state of matter in these machines --- the distribution of temperature and density, chemical composition,
flow velocities --- can be determined through diagnostic analysis of observational data in which models,
incorporating the full physics of the object, confront the observations.
This information is fundamental for our understanding of the behaviour of magnetic fusion plasmas
and key to harnessing them, e.g. via the proposed DEMO demonstration power plant.

Collisions of electrons with atoms, ions and molecules play a fundamental role in characterizing
magnetic fusion plasmas. The important fole of tungsten in present (JET/ASDEX) and future (ITER)
machines is a challenge for atomic physics and modelling based upon it.

We propose a series of calculations which are essential to reliably model and interpret observations
from these plasmas. We will also carry-out such modelling applicable to the present day machines."
17-Jan-2014 - 16-Jan-2017
UK APAP Network
Badnell, Nigel (Principal Investigator)
"Plasmas permeate our Universe, being present in stellar atmospheres, interstellar gas clouds in galaxies, planetary nebulae, supernova remnants, black hole accretion disks, and so on. Spectroscopy of all these objects has shown a richness of information, in particular in the spectral lines that are emitted by the ions that are present in the plasmas.
In recent years, an overwhelming amount of XUV spectroscopic data have been obtained from the satellite missions such as SOHO, Hinode, STEREO, SDO (solar) and Chandra, XMM-Newton, HST, FUSE (non-solar).
The state of matter in each object --- the distribution of temperature and density, chemical composition, flow velocities --- can be determined through diagnostic analysis of spectral data in which models, incorporating the full physics of the object, confront the observations. This information is fundamental for our understanding of the origin and evolution of the Universe.

Collisions of electrons and photons with atoms, ions and molecules play a fundamental role in characterizing astrophysical plasmas, and it is therefore necessary that accurate atomic data are calculated. It might be surprising, but a large fraction of the spectra produced by ions is still unexplored.
Large discrepancies between observations and theory are also still present.
In recent years, we have shown the need to perform accurate calculations of electron-ion collisions for individual ions, in order to solve the large, long-standing discrepancies between observed and calculated line intensities in collisional (astrophysical and laboratory) plasmas.

We propose a series of calculations which will enable us to interpret spectral data from these satellites which will further our understanding of the solar corona, stellar atmospheres, supernova remnants, nebulae and stars.
With this proposal, we aim to strengthen the collaboration between experimental, observational and theoretical research. Our work will also impact upon the magnetic fusion program and its quest for a safe, reliable and environmentally friendly energy source."
01-Jan-2012 - 30-Jan-2015
UK APAP Network
Badnell, Nigel (Principal Investigator)
Plasmas permeate our Universe, being present in stellar atmospheres, interstellar gas clouds in galaxies, planetary nebulae, supernova remnants, black hole accretion disks, and so on. Spectroscopy of all these objects has shown a richness of information, in particular in the spectral lines that are emitted by the ions that are present in the plasmas. In recent years, an overwhelming amount of XUV spectroscopic data have been obtained from missions such as Chandra, XMM-Newton, HST, FUSE, SOHO. The state of matter in each object --- the distribution of temperature and density, chemical composition, flow velocities --- can be determined through diagnostic analysis of spectral data in which models, incorporating the full physics of the object, confront the observations. This information is fundamental for our understanding of the origin and evolution of the Universe. Collisions of electrons and photons with atoms, ions and molecules play a fundamental role in astrophysical plasmas, and it is therefore necessary that accurate atomic data are calculated. It might be surprising, but a large fraction of the spectra produced by ions is still unexplored. Large discrepancies between observations and theory are also still present. For example, there are order-of-magnitude anomalies in the derived elemental abundances in H II regions and Planetary Nebulae. A mis-match between observation and theory is also present in the X-ray spectra of Active Galactic Nuclei (AGN). We intend to perform new calculations of electron-ion recombination rate coefficients to address these discrepancies. In recent years, we have shown the need to perform accurate R-matrix calculations of electron-ion collisions for individual ions, in order to solve the large, long-standing discrepancies between observed and calculated line intensities in collisional (astrophysical and laboratory) plasmas. We propose extending these calculations to all isolectronic sequences from H-like up to Na-like, providing a comprehensive and accurate dataset for all important ions. The theoretical data need to be assessed and benchmarked against astrophysical and laboratory measurements, in particular, in order to identify spectral lines and to provide accurate wavelengths and uncertainty estimates. We intend to provide all of these fundamental and derived data to the wider user community by setting up a web-based archive which will contain all of the atomic data needed to interpret, with physical modelling, the spectra of astrophysical and laboratory plasmas. With this proposal, we aim to strengthen the collaboration between experimental, observational and theoretical research.
01-Jan-2007 - 28-Jan-2011
Travel to collaborate on experiments, interpretative models and data analysis on the JET, MAST, TEXTOR and ASDEX magnetic confinement fusion devices
Summers, Hugh (Principal Investigator) Badnell, Nigel (Co-investigator)
14-Jan-2005 - 30-Jan-2007

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