Page 2 - Progress minimizing fast-ion charge-exchange loss associated with gas injection on C-2W
P. 2
Overview
• C-2W1 (Norman) plasma consists of an FRC embedded in a magnetic mirror scrape-off-layer (SOL).
• Large-orbit fast ions from NBI stabilize MHD and ion-scale microturbulence in the FRC2,3.
• Particle fueling from NBI alone is insufficient to maintain plasma density: additional fueling
is required.
• Unlike tokamaks fast ion orbits extend far into the SOL.
• Gas injection near midplane (even super-sonic) leads to fast ion loss through
charge-exchange
• Neutral particle transport and fast ion modeling indicate gas injection
in end-bell and mirror throat avoid fast ion loss.
• Experimental results are consistent with modeling. For gas injection
in the mirror throat:
• Tangential (27 cm impact parameter) gas injection primarily fuels boundary. • Radial gas injection appears to fuel FRC core and is more efficiently ionized.
• Future work will explore higher fueling rates from balanced (azimuthally opposed) radial gas injection in the mirror throat.
1Gota, H., et. al., Nuclear Fusion 59 11 2019
2Schmitz, L., et. al., Nature Communications 17 2016 3Lau, C. K., et. al., Physics of Plasmas 24 8 2017
Presenter: Erik Granstedt 2
