Magnetic field configurational study on a helicon-based plasma source for future neutral beam systems. (4th September 2019)

• Record Type: Journal Article
• Authors: Ahmed, Kamal M; Agnello, Riccardo; Béchu, Stéphane; Cartry, Gilles; de Esch, H P L; Furno, Ivo; Guittienne, Philippe; Howling, Alan; Jacquier, Rémy; Morgal, Iaroslav; Sadeghi, Nader; Simonin, Alain
• Is Part Of: Plasma sources science & technology. Volume 28:Number 9(2019:Sep.)
• Publication Date: 2019-09-04
• Subjects: NBI -- Helicon plasma source -- B-dot measurements -- Fulcher-α -- gas temperature; Plasma (Ionized gases) -- Periodicals; 530.44
• DOI: 10.1088/1361-6595/ab3705
• Languages: English
• ISSNs: 0963-0252

Abstract

Abstract: A helicon-based plasma source is under development and exploration at CEA-IRFM to produce an efficient and dense magnetized plasma column. The final objective of this development is the extraction and acceleration of a blade-like negative ion beam in view of future neutral beam injector systems for fusion reactors. The extraction of a negative ion beam from a magnetized plasma column requires a specific topology of the magnetic confinement, which significantly impacts the plasma parameters and wave propagation along the column. The magnetic confinement under investigation is based on water-cooled internal coils implemented under vacuum along the source (column) axis; these coils are supplied with a high DC current (∼1000 A), providing the axial magnetic field ( B // ∼ 10 mT). Different diagnostics developed in academic laboratories, such as 3D B-dot probes, optical emission spectroscopy and Langmuir probes, have been used for plasma characterization. The paper reports the experimental results obtained under different operating conditions of this particular magnetic confinement.