Technical Meeting on the Collisional-Radiative Properties of Tungsten and Hydrogen in Edge Plasma of Fusion Devices

This meeting will evaluate and recommend fundamental data concerning tungsten, hydrogen, their ions and molecules in the edge plasma region of experimental nuclear fusion devices with a view to quantifying and reducing the uncertainties in the modelling of its collisional, radiative and plasma-material interaction properties.

The meeting has been postponed and will now be held at IAEA HQ in Vienna, Austria, tentatively in October 2020. The Scientific Secretary is Kalle HEINOLA.

Organizing Committee

  • Ursel FANTZ (University of Augsburg, Germany)
  • Kalle HEINOLA (IAEA)
  • Christian HILL (IAEA)
  • Sebastiján BREZINSEK (Forschungszentrum Jülich, Germany)

Sessions

A. Experiments: Tokamaks, Linear Plasmas, Stellarators

Experimental devices: JET (attached/detached), AUG, DIII-D, MAGNUM, PSI-2, ITER , JT60-SA, T10

  • Metallic vs. graphite surfaces
  • Isotope experiments
  • Reflection and recycling
  • Surface conditions and processes
  • Spectroscopy and other methods
B. Modelling: Tokamaks, Linear Plasmas, Stellarators

Codes: SOLPS-ITER, EMC3-EIRENE, SONIC NEUT2D, EDGE2D-EIRENE, TOKAM3-X, SOLEDGE-EIRENE

  • Issues with benchmarks
  • Attached and detached conditions
  • Isotope effects
  • Spectroscopy
  • Neutral pressure benchmarks
C. Experiments: Atomic and Molecular Data, Cross Sections, Processes
  • Isotope effects
  • Rotationally and vibrationally-resolved spectroscopy
  • Highly-excited species
  • Mixed molecules
  • Other hydrogen-containing molecules
  • Spectroscopy tools
D. Modelling: Atomic and Molecular Data calculations
  • Convergent-close coupling methods
  • High-temperature molecular spectroscopic line lists
E. Collisional Radiative Models

Codes: YACORA, EIRENE, EUMONIA, NEUT2D

  • Outcome of EU-ADAS for molecules
  • Vibrationally resolved CR
  • Time dependent methods
  • Application to detached conditions
F. Needs and Conclusions
  • Publications
  • Potential CRP

Topics

Recombination rate coefficients for Wq+: experiments and theory

Existing experimental recombination rate coefficients and cross sections are known for electron energies up to several hundred eV (i.e. for W18+ – 21+ ). However, at low energies the total recombination cross sections are orders of magnitude above those for radiative recombination. EBITS can be used for obtaining recombination cross sections, but energies below about 20 eV are not accessible experimentally, and this is the region with largest theoretical uncertainty.

The role of external electromagnetic fields on dielectronic recombination: high fields may have a large effect on plasma rate coefficients. For example, in Fe15+ the dielectronic recombination can change by a factor of 3 at temperatures of 105 to 106 K and at an electric field strength of kV/cm.

Electron-impact ionization of Wq+

The effect of long-lived states: experimental electron-impact ionization cross sections for W1+ – 19+ with energies up to 1 keV exist. However, in the experiments even if the multiply-charged ions are stored for some time, the effect of long-lived excited states (in the parent ion beam) will be present in the cross section measurements. Fine energy scans and good statistics can reveal these metastable ions. Theoretical modelling of the resulting cross sections can provide information on the long-lived beam components. Fusion plasma will contain such species in long-lived excited states whose cross sections are needed.

Resonant processes in high charge states and their contribution to net ionization: it is necessary to explore which charge states of W might have resonant contributions and to assess the related cross sections (modelling with, for example, R-matrix methods may be necessary as experiments are challenging).

Electron-impact excitation of Wq+

There is a lack of experimental data for electron-impact excitations in W.

Charge-transfer collisions of Wq+ with plasma species

Particular species of interest are: H/D/T, He and He+. The cross sections are well known in general, but at very low energies their uncertainties are unquantified. As with electron-collision experiments involving multiply charged W, the role of metastable states is largely unknown.

Spectroscopic issues in the divertor region

Non-LTE modelling: near the divertor the electron density is higher and the temperature lower than in main plasma, but due to divertor conditions non-LTE modelling may be required: emission data are needed for W erosion assessments (maximum charge states anticipated are W6+ – 8+; excluding transient events, are higher charge states expected?) No reliable NLTE modelling exists for W0 – 5+.

Re-assessment of the role of MAR in tungsten machines: Molecular Assisted Recombination (MAR) can play an important role in assisting the volume recombination (by three-body and radiative recombination of atomic ions) in detached divertor plasma. Detailed investigations of MAR were done almost two decades ago, but on machines using carbon as a plasma-facing material. The properties of carbon and tungsten with respect to their interaction with hydrogen (i.e. the probability of H2 formation at their surfaces) are very different; therefore, the role of MAR in modern fusion devices may differ from that determined for carbon machines.

Tungsten charge state distributions: plasma transport may shape the W charge state distribution (CSD): transport effects may change the averaged charge density <Z> and broaden the spatial range. The CSD deviates from transport-free, equilibrium values and offers information on plasma transport, provided that adequate ionization balance calculations are available. This is crucial for ITER: plasma transport measurements focus on the ionization balance of W. In ITER there will be no low-Z neutral beams employed, which are used in other fusion devices to monitor and observe plasma transport.

Atomic and molecular data: theory and modelling

Collisional-Radiative (CR) modelling: the relation of CR modelling to plasma transport simulations; non-LTE code activities on testing CR codes for W; CR model implementations: configurational average (i.e. <Z>) vs. detailed models (up to thousands of charge states).

Molecular radiation of hydrogen and deuterium (OES and UV/VUV ranges): Detecting and interpreting molecular radiation gives access to molecular fluxes as well as vibrational and rotational populations: parameters that are of relevance to assessing the effectiveness of MAR (see above), The accuracy of modelling molecular radiation by collisional-radiative models is directly correlated with the accuracy and completeness of the set of input data used, including the cross sections for electron-impact excitation of molecular states. Up to now, two strongly-diverging sets of cross sections were available; the first steps towards establishing a more reliable and accurate alternative set are currently in progress.

The effect of opacity

Self-absorption caused by optical thickness of the atomic Lyman emission lines can result in significant radiation trapping, influencing the energy balance and the ionization / recombination rates in the divertor plasma. If the radiation trapping is high, this may make the transition to a detached divertor more difficult. A second effect of opacity is that it strongly affects the intensity of emission lines and has to be taken into account in population models used for interpreting such emission. To do so, profiles of the opacity along the line-of-sight used are needed; this information is not presently available.

Middle-charge states of W (W10+ – 25+)

In ITER medium charge states of W are expected to be responsible for the majority of re-radiation from transient pulses. Key processes for which data is needed are: ion line data and ionization, recombination and excitation rates.

Related Projects and Meetings

Agenda

Monday, 27 April 2020

09:00 – 09:30Meeting opening, welcome, introductions
Session 1: A.I. Experiments: Tokamaks, Linear Plasmas, Stellarators
09:30 – 10:00Sebastiján BREZINSEK (Forschungszentrum Jülich (FZJ), Germany)
presentation title to follow
10:00 – 10:30Motoshi GOTO (National Institute for Fusion Science, Japan)
presentation title to follow
10:30 – 11:00Coffee Break
Session 2: B.I. Modelling: Tokamaks, Linear Plasmas, Stellarators
11:00 – 11:30Xavier BONNIN (ITER, France)
presentation title to follow
11:30 – 12:00Sven WIESEN (Forschungszentrum Jülich (FZJ), Germany)
presentation title to follow
12:00 – 12:30Discussion
12:30 – 13:30Lunch
Session 3: A.II. Experiments: Tokamaks, Linear Plasmas, Stellarators
13:30 – 14:00Richard ENGELN (Eindhoven University of Technology, Netherlands)
presentation title to follow
14:00 – 14:30Alexander ZIMIN (Bauman Moscow State Technical University, Russia)
Digital Atlas of Electronic Vibrational-Rotational Transitions in Deuterium and Protium Molecules
14:30 – 15:00Ivo CLASSEN (Dutch Institute for Fundamental Energy Research (DIFFER), Netherlands)
presentation title to follow
15:00 – 15:30Coffee Break
Session 4: B.II. Modelling: Tokamaks, Linear Plasmas, Stellarators
15:30 – 16:00Mathias GROTH (Aalto University, Finland)
presentation title to follow
16:00 – 16:30Kevin VERHAEGH (Culham Centre for Fusion Energy, United Kingdom)
presentation title to follow
16:30 – 17:30Discussion

Tuesday, 28 April 2020

Session 5: D.I. Modelling: Atomic and Molecular Data calculations
09:00 – 09:30Martin G. O'MULLANE (Department of Physics, University of Strathclyde, United Kingdom)
presentation title to follow
09:30 – 10:00Xavier URBAIN (Université catholique de Louvain, Belgium)
presentation title to follow
10:00 – 10:30Man MOHAN (University of Delhi, India)
presentation title to follow
10:30 – 11:00Coffee Break
Session 6: A.3. Experiments: Tokamaks, Linear Plasmas, Stellarators
11:00 – 11:30Ewa PAWELEC (University of Opole, Poland)
presentation title to follow
11:30 – 12:00Presentation 20
12:00 – 12:30Discussion
12:30 – 13:30Lunch
Session 7: E.I. Collisional Radiative Models
13:30 – 14:00Detlev REITER (Heinrich Heine University Düsseldorf, Germany)
presentation title to follow
14:00 – 14:30Dirk WÜNDERLICH (Max Planck Institute for Plasma Physics, Garching, Germany)
presentation title to follow
14:30 – 15:00Annarita LARICCHIUTA (Polytechnic University of Bari, Italy)
presentation title to follow
15:00 – 15:30Coffee Break
Session 8: D.II. Modelling: Atomic and Molecular Data calculations
15:30 – 16:00Dmitry FURSA (Faculty of Science and Engineering, Curtin University, Australia)
presentation title to follow
16:00 – 16:30Alain DUBOIS (Laboratoire de Chimie Physique – Matière et Rayonnement (LCPMR), Sorbonne Université, France)
presentation title to follow
16:30 – 17:30Discussion
19:30 – 21:30Social Dinner

Wednesday, 29 April 2020

Session 9: D.III. Modelling: Atomic and Molecular Data calculations
09:00 – 09:30Xiaobin DING (Northwest Normal University, China)
presentation title to follow
09:30 – 10:00Muhammad Abbas BARI (Pakistan Institute of Engineering and Applied Sciences, Pakistan)
presentation title to follow
Session 10: C.I. Experiments: Atomic and Molecular Data, Cross Sections, Processes
10:00 – 10:30Baoren WEI (Fudan University, China)
presentation title to follow
10:30 – 11:00Coffee Break
11:00 – 11:30Rémy GUIRLET (Centre d'Etudes Nucleaires de Cadarache, Association EURATOM-CEA, France)
presentation title to follow
11:30 – 12:00Stephan ERTMER (Forschungszentrum Jülich (FZJ), Germany)
presentation title to follow
12:00 – 12:30Discussion
12:30 – 13:30Lunch
Session 11: B.III. Modelling: Tokamaks, Linear Plasmas, Stellarators
13:30 – 14:00Andreas KIRSCHNER (Forschungszentrum Jülich (FZJ), Germany)
presentation title to follow
14:00 – 14:30Jerome GUTERL (General Atomics, United States of America)
presentation title to follow
14:30 – 15:00David TSKHAKAYA (Institute of Plasma Physics of the Czech Academy of Sciences, Czechia)
presentation title to follow
15:00 – 15:30Coffee Break
Session 12: E.II. Collisional Radiative Models
15:30 – 16:00Connor BALLANCE (Queen's University Belfast, United Kingdom)
presentation title to follow
16:00 – 16:30Alina EKSAEVA (Forschungszentrum Jülich (FZJ), Germany)
presentation title to follow

Thursday, 30 April 2020

Session 13: Meeting Summary
09:00 – 09:30Session A Summary: Experiments: Tokamaks, Linear Plasmas, Stellarators
09:30 – 10:00Session B Summary: Modelling: Tokamaks, Linear Plasmas, Stellarators
10:00 – 10:30Session C Summary: Experiments: Atomic and Molecular Data, Cross Sections, Processes
10:30 – 11:00Coffee Break
11:00 – 11:30Session D Summary: Modelling: Atomic and Molecular Data calculations
11:30 – 12:30Session E Summary: Collisional Radiative Models
12:30 – 13:30Discussion; Meeting adjournment

Participants

45 participants from 17 countries.

Connor BALLANCE Queen's University Belfast, United Kingdom
Muhammad Abbas BARI Pakistan Institute of Engineering and Applied Sciences, Pakistan
Xavier BONNIN ITER, France
Sebastiján BREZINSEK Forschungszentrum Jülich (FZJ), Germany
Ivo CLASSEN Dutch Institute for Fundamental Energy Research (DIFFER), Netherlands
Xiaobin DING Northwest Normal University, China
Alain DUBOIS Laboratoire de Chimie Physique – Matière et Rayonnement (LCPMR), Sorbonne Université, France
Alina EKSAEVA Forschungszentrum Jülich (FZJ), Germany
Richard ENGELN Eindhoven University of Technology, Netherlands
Stephan ERTMER Forschungszentrum Jülich (FZJ), Germany
Dmitry FURSA Faculty of Science and Engineering, Curtin University, Australia
Motoshi GOTO National Institute for Fusion Science, Japan
Mathias GROTH Aalto University, Finland
Rémy GUIRLET Centre d'Etudes Nucleaires de Cadarache, Association EURATOM-CEA, France
Jerome GUTERL General Atomics, United States of America
Andreas KIRSCHNER Forschungszentrum Jülich (FZJ), Germany
Annarita LARICCHIUTA Polytechnic University of Bari, Italy
Man MOHAN University of Delhi, India
Martin G. O'MULLANE Department of Physics, University of Strathclyde, United Kingdom
Ewa PAWELEC University of Opole, Poland
Detlev REITER Heinrich Heine University Düsseldorf, Germany
David TSKHAKAYA Institute of Plasma Physics of the Czech Academy of Sciences, Czechia
Xavier URBAIN Université catholique de Louvain, Belgium
Kevin VERHAEGH Culham Centre for Fusion Energy, United Kingdom
Baoren WEI Fudan University, China
Sven WIESEN Forschungszentrum Jülich (FZJ), Germany
Dirk WÜNDERLICH Max Planck Institute for Plasma Physics, Garching, Germany
Alexander ZIMIN Bauman Moscow State Technical University, Russia
Christian HILL IAEA
Kalle HEINOLA IAEA
Ursel FANTZ Max Planck Institute for Plasma Physics, Garching, Germany
Ioan F. SCHNEIDER Université du Havre, France
Bowen LI Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, China
Evgeny STAMBULCHIK Weizmann Institute, Israel
Yong WU Institute of Applied Physics and Computational Mathematics (IAPCM), China
Hennie VAN DER MEIDEN Dutch Institute for Fundamental Energy Research (DIFFER), Netherlands
Robin BARNSLEY ITER, France
Dmitry BORODIN Forschungszentrum Jülich (FZJ), Germany
Andreas KIRSCHNER Forschungszentrum Jülich (FZJ), Germany
Narendra SINGH University of Delhi, India
Jonathan TENNYSON University College London, United Kingdom
Rudolf NEU Technical University of Munich, Germany
Marco WISCHMEIER Max Planck Institute for Plasma Physics, Garching, Germany
Sk. Musharaf ALI Bhabha Atomic Research Centre, India
Thierry KREMEYER University of Wisconsin-Madison, United States of America

Presentations

Connor BALLANCE (Queen's University Belfast, United Kingdom)
presentation title to follow

Muhammad Abbas BARI (Pakistan Institute of Engineering and Applied Sciences, Pakistan)
presentation title to follow

Xavier BONNIN (ITER, France)
presentation title to follow

Sebastiján BREZINSEK (Forschungszentrum Jülich (FZJ), Germany)
presentation title to follow

Ivo CLASSEN (Dutch Institute for Fundamental Energy Research (DIFFER), Netherlands)
presentation title to follow

Xiaobin DING (Northwest Normal University, China)
presentation title to follow

Alain DUBOIS (Laboratoire de Chimie Physique – Matière et Rayonnement (LCPMR), Sorbonne Université, France)
presentation title to follow

Alina EKSAEVA (Forschungszentrum Jülich (FZJ), Germany)
presentation title to follow

Richard ENGELN (Eindhoven University of Technology, Netherlands)
presentation title to follow

Stephan ERTMER (Forschungszentrum Jülich (FZJ), Germany)
presentation title to follow

Dmitry FURSA (Faculty of Science and Engineering, Curtin University, Australia)
presentation title to follow

Motoshi GOTO (National Institute for Fusion Science, Japan)
presentation title to follow

Mathias GROTH (Aalto University, Finland)
presentation title to follow

Rémy GUIRLET (Centre d'Etudes Nucleaires de Cadarache, Association EURATOM-CEA, France)
presentation title to follow

Jerome GUTERL (General Atomics, United States of America)
presentation title to follow

Andreas KIRSCHNER (Forschungszentrum Jülich (FZJ), Germany)
presentation title to follow

Annarita LARICCHIUTA (Polytechnic University of Bari, Italy)
presentation title to follow

Man MOHAN (University of Delhi, India)
presentation title to follow

Martin G. O'MULLANE (Department of Physics, University of Strathclyde, United Kingdom)
presentation title to follow

Ewa PAWELEC (University of Opole, Poland)
presentation title to follow

Detlev REITER (Heinrich Heine University Düsseldorf, Germany)
presentation title to follow

David TSKHAKAYA (Institute of Plasma Physics of the Czech Academy of Sciences, Czechia)
presentation title to follow

Xavier URBAIN (Université catholique de Louvain, Belgium)
presentation title to follow

Kevin VERHAEGH (Culham Centre for Fusion Energy, United Kingdom)
presentation title to follow

Baoren WEI (Fudan University, China)
presentation title to follow

Sven WIESEN (Forschungszentrum Jülich (FZJ), Germany)
presentation title to follow

Dirk WÜNDERLICH (Max Planck Institute for Plasma Physics, Garching, Germany)
presentation title to follow

Alexander ZIMIN (Bauman Moscow State Technical University, Russia)
Digital Atlas of Electronic Vibrational-Rotational Transitions in Deuterium and Protium Molecules