Lyman line opacities in tokamak divertor plasmas under high-recycling and detached conditions

Radiation transport simulations of the deuterium Lyman line series using EIRENE predict a factor of 2 increase of Balmer-α emission in the JET-ILW low confinement divertor plasmas in high-recycling and detached conditions caused by the re-absorption of Lyman-β emission. The photon tracing model in t...

Full description

Saved in:
Bibliographic Details
Main Authors: Ray Chandra, Detlev Reiter, Niels Horsten, Mathias Groth
Format: Article
Language:English
Published: Elsevier 2024-12-01
Series:Nuclear Materials and Energy
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2352179124002175
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Radiation transport simulations of the deuterium Lyman line series using EIRENE predict a factor of 2 increase of Balmer-α emission in the JET-ILW low confinement divertor plasmas in high-recycling and detached conditions caused by the re-absorption of Lyman-β emission. The photon tracing model in the EIRENE code is applied to SOLPS-ITER pure deuterium plasma solutions of JET-ILW to evaluate the contribution of Lyman-β capture towards the population density of D(p=3) and, consequently, the Balmer-α emission. The local population escape factors of Lyman-α and Lyman-β lines in the JET-ILW divertor show steep spatial gradients and indicate local regions with high opacity in high-recycling and detached conditions. The relative contribution of Lyman-β capture towards the population density of D(p=3) is significant in high-recycling and detached conditions. This observation is further corroborated by line-integrated calculations using Balmer-α diagnostic line-of-sights.
ISSN:2352-1791