2014 Joint ICTP-IAEA Conference on Models and Data for Plasma-Material Interaction in Fusion Devices

(The event has concluded. This web page serves as a record and it provides links to many of the presentations that were given in the school and workshop.)

The Abdus Salam International Centre for Theoretical Physics (ICTP, Trieste, Italy) in cooperation with the International Atomic Energy Agency (IAEA, Vienna, Austria) is organizing a Conference on Models and Data for Plasma-Material Interaction in Fusion Devices. The conference will bring together researchers from fusion energy science and materials science in order to review advances in computational studies of plasma-material interaction processes and evolution of material microstructure in fusion devices, including effects of radiation damage and with special interest in hydrogen (tritium) trapping and transport in wall material.

Dates: 03-07 November 2014.

Location: ICTP - Miramare, Trieste, Italy.

Directors: B. J. Braams and H.-K. Chung (IAEA).
Local organizer: S. Scandolo (ICTP).
Administrative support: Ms A. Lusenti (ICTP).
Email: smr2614@ictp.it.

ICTP Activity Announcement (A3 Poster).

ICTP Event Web Page (Event a13232, SMR2614).

Summary Report and Book of Abstracts.

Participants and Group Photo.

Special Section in Journal of Nuclear Materials

Following the event at ICTP manuscripts were solicited for a theme issue of Journal of Nuclear Materials (JNM) on "Models and Data for Plasma-Material Interaction and Hydrogen Retention in Fusion Devices" (short title: Models and Data for PMI) with Bastiaan Braams and Hyun-Kyung Chung as Guest Editors. Contributions were refereed according to the regular standards of the journal and in the end 12 articles were published in a special section (pp 397-487) of Vol 467, publication date December 2015. Please find the special section by following the link to Vol 467 on the JNM home page at Science Direct.

Introduction

Plasma-wall interaction in fusion devices encompasses a wide variety of processes. On a short timescale these include deposition of energetic plasma particles (primarily hydrogen and helium) into the surface, physical and chemical sputtering of surface material into the plasma, and reflection and desorption of particles from the surface. On a longer timescale the processes include diffusion of hydrogen and helium in the wall and changes in surface composition, morphology and material microstructure due to plasma bombardment and (in a reactor) neutron irradiation. Together these processes are extremely important in determining the plasma performance, the lifetime of plasma-facing components, trapping and retention of the tritium fusion fuel in the wall, and ultimately the feasibility of fusion power production.

The gap between what is known about plasma-material interaction and what is needed to design a fusion reactor is most severe for the effects of radiation damage on hydrogen retention properties of plasma-facing materials. Computations are particularly important for this problem, because experiments cannot fully simulate the radiation conditions in a fusion device. Appropriate computational materials tools range from statistical or otherwise averaged (binary collision approximation, kinetic Monte Carlo) and mechanical (molecular dynamics) models to semiempirical (tight binding) density functional theory codes and the best possible "first principles" electronic structure codes for inhomogeneous materials. Any of these codes has its own needs for fundamental data, which are in many cases obtained by parameterization of results of other calculations.

Purpose

The conference is intended to bring together researchers from the areas of fusion energy science and materials science in order to review advances in computational studies of plasma-material interaction processes and the evolution of material microstructure in fusion devices. Within this area the programme will emphasize work that is relevant to hydrogen (tritium) trapping and transport in candidate fusion reactor wall materials. This includes modelling of the effects of irradiation upon material microstructure and modelling to understand the influence of microstructure on hydrogen trapping and transport.

Participants with a background in plasma-wall interaction in fusion experiments should return from the conference with a richer understanding of the wide range of computational methods that are used for development of plasma-material interaction data and material properties data for fusion plasma and fusion materials modelling. Participants from the area of materials science should obtain guidance about new work that is most needed to improve understanding of plasma-material interaction processes and material damage processes that are relevant for fusion energy development. The conference format is meant to encourage new collaborations on computational studies of plasma-material interaction in fusion devices.

Topics

The conference programme will emphasize uses of the more fundamental computational tools (based on quantum mechanics) and parameterization of results from such tools in the form of interaction potentials and transition rates for applied studies. Specific topics include the following.

Participants will be active researchers in the subject area of the conference and we expect a scientific contribution (talk or poster) from each participant.

Location

The conference is held in the Leonardo Building on the ICTP campus. The campus is located next to Miramare Park and Castle, about 7 km from the centre of Trieste.

Image courtesy, credit and/or copyright (c) ICTP. Source: ICTP Media Centre (> Picture Gallery > ICTP Campus).

Schedule as Realized

All events are in the Leonardo da Vinci Building (ICTP main building). The talks are in the Euler lecture hall.

The active link for each presentation goes to a pdf file of the talk or poster. Summaries prepared before the meeting are in the Book of Abstracts.

Monday 03 November 2014

08:30 - 09:00 Ave Lusenti: Registration in the Main Lobby, Leonardo da Vinci Building
09:00 - 09:15 Sandro Scandolo, Bas Braams, Hyun-Kyung Chung: Welcome.
09:15 - 10:00 Christian Linsmeier, FZ Jülich, Germany: Hydrogen isotope retention and release in beryllium: The full picture from experiment and ab initio calculations. (Lecture)
10:00 - 10:45 Break; registration continues.
10:45 - 11:30 Kai Nordlund and Jussi Polvi, University of Helsinki, Finland: Multiscale modelling of hydrogen and helium in tungsten and Development of an interatomic potential for W-N-H system.
11:30 - 11:55 Jean Paul Allain, UIUC, Illinois, USA: Challenges and strategies to experimental validation of multi-scale nuclear fusion PMI computational modeling.
11:55 - 12:20 Manoj Warrier, BARC, Autonagar, Visakhapatnam, India: Statistical study of defects caused by primary knock-on atoms in fcc and bcc metals using molecular dynamics simulations.
12:20 - 14:00 Lunch
14:00 - 14:25 Dorothy Duffy, UCL, London, United Kingdom: Modelling the electronic excitation induced structural dynamics of tungsten.
14:25 - 14:50 Duc Nguyen-Manh, CCFE, Abingdon, United Kingdom: Trapping of He clusters by inert-gas impurities in refractory bcc transition metals: systematic first-principles predictions and experimental validations.
14:50 - 15:15 Takuji Oda, SNU, Seoul, Korea: Development of a potential model for tritium behavior in tungsten.
15:15 - 16:15 Break
16:15 - 16:40 Paul Erhart, Chalmers UT, Gothenburg, Sweden: Mesoscale mean-field modeling of neutron irradiation damage accumulation in tungsten for fusion applications.
16:40 - 17:05 Mihai-Cosmin Marinica, CEA, Gif-sur-Yvette, France: Energy landscape of radiation-induced point defects in body centered cubic metals.
17:05 - 17:30 Christian Linsmeier, FZ Jülich, Germany: Brief review of materials issues for DEMO, introduction to a discussion.
18:00 - 20:00 Welcome reception

Tuesday 04 November 2014

08:30 - 08:55 Brian Wirth, UT, Knoxville, USA: Helium gas clustering dynamics in tungsten exposed to helium plasmas.
08:55 - 09:20 Maria Ganchenkova, MEPhI, Moscow, Russia: Calculation of defects and hydrogen in tungsten: fundamental parameters and methodological aspects.
09:20 - 09:45 Alfredo Caro, LANL, Los Alamos, USA: The capillarity equation at the nanoscale: size effects on gas bubbles in metals.
09:45 - 10:45 Break
10:45 - 11:10 Predrag Krstic, SUNY, Stony Brook, USA: The atomistic phenomena at the plasma-surface interfaces.
11:10 - 11:35 Robert Harrison, SUNY and BNL, Brookhaven, USA: Getting started with Uncertainty Quantification for plasma-material interactions.
11:35 - 12:00 Poster authors: Minitalks to introduce the posters.
12:00 - 14:00 Lunch
14:00 - 16:00 Poster Session. See below. Posters will remain up Wed-Thu.
16:00 - 16:30 Break
16:30 - 17:30 Robert Harrison, SUNY and BNL, Brookhaven, USA: Institute Colloquium: Seeking a sustainable model for scientific simulation.

Wednesday 05 November 2014

08:30 - 08:55 Charlotte Becquart, University of Lille, France: Modelling self trapping and trap mutation in tungsten using DFT and molecular dynamics with an empirical potential based on DFT.
08:55 - 09:20 Yves Ferro, Aix-Marseille University, France: H trapping and migration in W: A DFT investigation that includes temperature dependency.
09:20 - 09:45 Daiji Kato, NIFS, Toki-City, Japan: Multiple hydrogen trapping by vacancies: its impact on defect dynamics and hydrogen retention in tungsten.
09:45 - 10:45 Break
10:45 - 11:10 Gábor Csányi, University of Cambridge, UK: Constructing interatomic potentials from first principles using machine learning: the example of tungsten.
11:10 - 11:35 Hong-Bo Zhou, Beihang University, Beijing, China: Electrophobic interaction: the leading mechanism for helium self-trapping in metals.
11:35 - 12:00 Miroslav Urban, Slovak University of Technology in Bratislava, Slovak Republic: Many-body decomposition of the interaction energy in lowest beryllium clusters Be[3-8].
12:00 - 14:00 Lunch
14:00 - 14:25 Alexander Barashev, ORNL, Oak Ridge, TN, USA: Helium interaction with tungsten surfaces and subsequent evolution from atomistic simulations.
14:25 - 15:45 Discussion Session I on electronic structure computations and the development of MD potentials. Questions:
- 1a: What is the role of electronic excited states and how can effects of electronic excitation be included in the models and data?
- 1b: Are we satisfied with present strategies for the development of MD potentials from electronic structure calculations?
15:45 - Free time

Thursday 06 November 2014

08:30 - 08:55 Tomoaki Suzudo, JAEA, Tokai-mura, Japan: Migration of rhenium and osmium in tungsten.
08:55 - 09:20 Vladimir Borodin, RNC "Kurchatov Institute" and MEPhI, Moscow, Russia: Primary defect production in displacement cascades in beryllium.
09:20 - 09:45 Mike Demkowicz, MIT, Cambridge, USA: Design of composite materials for outgassing of implanted He.
09:45 - 10:45 Break
10:45 - 11:10 Luis Sandoval, LANL, Los Alamos, NM, USA: Growth of helium bubbles in tungsten under realistic rates.
11:10 - 11:35 Jaime Marian, University of California, Los Angeles, CA, USA: Mesoscale mean-field modeling of neutron irradiation damage accumulation in tungsten.
11:35 - 13:00 Lunch
13:00 - 14:30 Discussion Session II on long-time evolution calculations and the development of KMC rates. Questions:
- 2a: What is the role of nuclear quantum effects and how can these effects be included in the models and data?
- 2b: Is it desirable and feasible to develop standard definitions for the objects in KMC models?
14:30 - Free time

Friday 07 November 2014

08:30 - 08:55 Zhongshi Yang, CAS-IPP, Hefei, China: Present status of plasma-surface interaction investigations for EAST and CFETR.
08:55 - 09:20 Armin Manhard, IPP Garching, Germany: Comparison of a quantitative diffusion-trap model with experiments on D uptake in damaged W.
09:20 - 09:35 (C) Régis Bisson, Aix-Marseille Université, Marseille, France: Bridging model and real systems with laboratory experiments: dynamic retention of deuterium in tungsten.
09:35 - 09:50 (C) Sabina Markelj, Josef Stefan Institute, Ljubljana, Slovenia: In situ study of isotope exchange mechanism in self-ion damaged tungsten.
09:50 - 10:45 Break
10:45 - 11:00 (C) Maria Rutigliano, CNR-IMIP, Bari, Italy: Hydrogen atom recombination on tungsten at high temperature: a combined experimental and theoretical work.
11:00 - 11:15 (C) Petrica Cristian Lungu, INFLPR, Magurele, jud Ilfov, Romania: Periodic structures formation on beryllium, carbon, tungsten films mixed films by TW laser irradiation.
11:15 - 11:30 Ahmed Hassanein, Purdue University, USA: Effect of thermal and collisional processes on the performance of plasma-facing components in mixed materials environment. (Presented by Predrag Krstic.)
11:30 - 13:00 Discussion Session III on uncertainties in comprehensive modelling for present and future experiments. Questions:
- 3a: What are the most important model uncertainties for calculation of damage in fusion wall materials (primarily tungsten and steel) by neutrons and fast particles?
- 3b: What are the most important model uncertainties for calculation of hydrogen trapping and transport in fusion wall materials?
- 3c: What are some priorities for experimental information to help assess errors and uncertainties in models?
13:00 - 14:00 Lunch
14:00 - Free time.

Poster Session

The dedicated poster session is on Tuesday, 14:00-16:00, but posters can stay up through Thursday. The poster boards have dimension 1.25m (height) by 1.22m (width).

(Additional posters from invited speakers:)

Discussion Sessions

The conference schedule has discussion sessions at the end of the programme on Wednesday, Thursday and Friday. Session I on Wednesday is concerned with electronic structure computations and the development of MD potentials. Session II on Thursday is concerned with long-time evolution calculations and the development of KMC rates. Session III on Friday is concerned with uncertainties in comprehensive modelling for present and future experiments. The discussions are all intended in the context of this conference: radiation damage and its influence on hydrogen and helium migration in fusion wall materials. In each of the 3 sessions some topics will be highlighted as indicated in the meeting schedule.

Related Meetings

The IAEA Atomic and Molecular Data Unit has two related meetings in the near future.

In 2016 we again plan an ICTP event on PMI, this time to be held in Hefei, China, and hosted by the Chinese Academy of Sciences (CAS) Institutes of Plasma Physics (IPP) and Solid State Physics (ISSP).

The ICTP event also served as the kick-off for a MoD-PMI meeting series with instances (so-far) in 2015 and 2016.

The present conference has been advertised on several meetings lists and these lists may be a good source of information about many other events of related interest.

For problems or questions regarding this web page contact the A+M Data Unit.