NEW CRP: Atomic Data for Vapour Shielding in Fusion Devices (F43024)

IAEA July 11, 2018

An illustration of the interactions between ions and neutrals in a plasma vapour shield. (Illustration: IAEA)

The IAEA is launching a new 3-year Coordinated Research Project (CRP) in order to assemble, validate and distribute atomic, molecular and plasma-material interaction data for nuclear fusion energy development. Upon conclusion, the CRP is expected to provide an authoritative and evaluated set of data relevant to vapour shielding with particular emphasis on liquid metals.

In the magnetic confinement approach to fusion, a deuterium-tritium (D-T) plasma at a temperature of 170 million °C is trapped in a magnetic field inside a vacuum vessel. The confinement is not perfect and energy from the plasma may be directed towards the walls of the vessel due to transient instabilities in the plasma. These disruptions can lead to unwanted damage such as evaporation or ablation to the wall, and their mitigation is an important and ongoing field of research in the development of experimental fusion reactors such as ITER and DEMO.

When wall material is evaporated in this way, it forms its own dense expanding plasma in front of the wall surface which can, in some circumstances, reduce the further energy absorbed by the wall. This effect is referred to as vapour shielding and must be properly understood to accurately estimate the wall material’s lifetime. However, there are major gaps in the atomic and molecular data necessary to model the effects of vapour shielding. This CRP will address some of those gaps and help the community in assessing the viability of different materials for use in fusion reactor components, particularly the innovative use of materials such as liquid metals.

The IAEA is uniquely placed to facilitate global, collaborative research of the kind needed to provide and evaluate data for fusion. In bringing experimentalists and theorists producing fundamental atomic and molecular data together with fusion researchers and plasma physicists, this CRP will enable international cooperation on a scale that is otherwise hard to achieve and can host the resulting data in a permanent and trusted repository.

CRP Overall Objective:

The primary goal of this CRP is to increase the capability of Member States to undertake fusion plasma and fusion materials modelling by supporting the development of novel techniques in fusion reactor design. This will be accomplished through the enhancement of the global knowledgebase of atomic and molecular data for vapour shielding modelling, with a particular focus on liquid metals.

Specific Research Objectives:

To assemble, evaluate and recommend atomic and molecular data needed for the modelling of vapour shielding, particularly cross sections for ionization, recombination, charge exchange (CX), rovibrational excitation (for molecules) and momentum transfer. Also of concern are data for radiative processes inside vapours, including line shapes, emission and absorption coefficients, radiative cooling rates, stopping power, and other radiative properties of warm dense matter. The comparison of theory with experiment should be achieved wherever possible.

  • To assess the impact of impurities such as oxygen (O), carbon (C) and nitrogen (N) in their interactions with liquid metal species, particularly lithium (Li).
  • To assemble, evaluate and recommend relevant data on metal hydrides for vapour shielding models, particularly those involving Li and Tin (Sn).
  • To investigate the effect of surface chemistry, especially hydrogen co-deposition, on sputtering and evaporation of plasma-facing materials.

How to join the CRP:

Please submit your Proposal for Research Contract or Agreement by email to the IAEA’s Research Contracts Administration Section using the appropriate template on the CRA website.

For further information related to this CRP, potential applicants should write to the Research Contracts Administration Contact Point.