2023/12/25 by K. Nagaoka, H. Nakano, Nagaoka, Kenichi +19
Engineering · Physics and Astronomy · #Accelerator Physics (physics.acc-ph) #FOS: Physical sciences #Gyrotron and Vacuum Electronics Research #Particle accelerators and beam dynamics #Plasma Diagnostics and Applications #Plasma Physics (physics.plasm-ph)
paper · pdf · doi:10.48550/arxiv.2312.15749
openalex publication_date 2023/12/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Beam-focusing characteristics of negative ion beams have been experimentally investigated with a superimposition of a controlled perturbation of RF field in a filament-arc discharge negative ion source. Oscillations of a negative-ion beamlet width and axis responding to the RF perturbation were observed, which may be a cause of the larger beam divergence angle of the RF negative ion source for ITER. It is pointed out that the oscillation of the beamlet width depends on the perveance and on the RF frequency such that the oscillation is suppressed at perveance-matched conditions and at low RF frequency.