Towards improved neutral exhaust in the HSX stellarator

Journal Article · 19 February 2025 · Nuclear Materials and Energy

DOI: https://doi.org/10.1016/j.nme.2025.101874 · OSTI ID:2520572

Boeyaert, Dieter  ^[1]; Garcia, Kelly A.  ^[1]; Frerichs, Heinke  ^[1]; Gerard, Michael J.  ^[1]; Bader, Aaron  ^[2]; Davies, Robert  ^[3]; Geiger, Benedikt  ^[1]; Schmitt, John  ^[2]; Schmitz, Oliver  ^[1]

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1. Univ. of Wisconsin, Madison, WI (United States)
2. Type One Energy Inc., Madison, WI (United States)
3. Max Planck Institute for Plasma Physics, Greifswald (Germany)

To improve our knowledge of neutral exhaust in non-resonant divertors, a particle exhaust study is performed for the Helically Symmetric eXperiment (HSX). The chaotic magnetic field topology in the plasma edge is examined with connection lengths and Lyapunov exponents. Plasma flux tubes are identified and these flux tubes deposit particles onto plasma facing components. This helps determine the areas where neutrals are generated and provides guidance on where to put baffles. As shown using EMC3-EIRENE simulations, the introduction of baffles can help increase the neutral pressure at and away from the strike line locations. Furthermore, it is demonstrated that baffle design cannot only be based on placing structures at locations with small connection lengths.

• Research Organization: Univ. of Wisconsin, Madison, WI (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF); USDOE Office of Science (SC), Fusion Energy Sciences (FES)
• Grant/Contract Number: AC02-05CH11231; FG02-93ER54222; SC0014210
• OSTI ID: 2520572
• Journal Information: Nuclear Materials and Energy, Journal Name: Nuclear Materials and Energy Vol. 42; ISSN 2352-1791
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English