Neutral Beam Penetration and Photoemission

Scope and motivation

This code comparison exercise is intended to assess the sensitivity of predictions of hydrogen beam penetration and of beam emissions in relevant fusion plasma conditions to different modelling codes and uncertainties in atomic data. It was conceived in order to support the aims of the Neutral Beams CRP which will provide evaluated and recommended data for the principal atomic processes relevant to heating and diagnostic neutral beams in fusion plasmas.

The workshop should bring together neutral beam modellers that may use a variety of atomic models and data. Relevant processes include excitation and deexcitation of beam neutrals by electron and ion impact (including impact by impurity ions), ionization from the ground state or from relevant excited states by electron and ion impact, and charge transfer resolved with respect to the excitation state of the pre-collision neutral H and the post-collision impurity ion. The comparison exercise will help modellers to identify possible errors in the atomic data and to identify important sensitivities of the simulations of beam penetration and beam-based emissions to uncertainties in the atomic data.

Workshop

A Workshop will be held in Debrecen, Hungary from 26 – 28 August 2019 to compare the results of this exercise. Remote participation will be possible, but researchers are encouraged to attend in person if at all possible.

Important Dates

by 20 August 2019Upload test results and code description
26 – 28 August 2019Code comparison workshop
20 November 2019Completion of comparison article

Organizing Committee

  • Christian HILL, IAEA
  • Gergő POKOL, Institute of Nuclear Techniques, Budapest University of Technology and Economics, Hungary
  • Károly TŐKÉSI, Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), Debrecen, Hungary
  • Oleksandr MARCHUK, Forschungszentrum Jülich, Germany

Test cases

Details of the test cases are available as an Excel chart and also for download from a shared Google drive folder. They involve H, D, He, and (optionally) Li and Na, at beam energies of 30, 100 and 1000 keV and plasma conditions representative of those present in fusion devices. To facilitate effective benchmarking, a constant plasma profile is considered. However, additional, three sets of variable conditions of temperature and density along the beam are be provided for optional consideration:

  • ITER_134000_5.txt: ITER scenario
  • fluct_ITER_134000_5.txt: ITER scenario with a single temperature/density fluctuation
  • island_divertor.txt: Density and temperature profiles based on W7-X island divertor high density scenario taken at midplane bean shape cross section.
Density and temperature profiles taken from ITER IMAS
Density and temperature profiles taken from ITER IMAS. Data originally stored in IDS. Shot 134000 Run 5 (Modelling done with JINTRAC) ITER shot at 15 MA and Q=10 with a Pfus =530 MW and a burn duration of several seconds. See Garzotti et al., Nuclear Fusion 59 026006 for further details.
Density and temperature profiles taken from ITER IMAS, with added fluctuation
Density and temperature profiles taken from ITER IMAS database, shot: 134000 at run 5. A density and temperature fluctuation was added with an amplitude of one order of magnitude higher of local density. Fluctuation amplitude was justified based on HESEL modelling.
Density and temperature profiles based on W7-X island divertor high density scenario taken at midplane bean shape cross section.
Density and temperature profiles based on W7-X island divertor high density scenario taken at midplane bean shape cross section.