Document Type
Article
Publication Date
3-1-2026
Abstract
Particle-in-cell simulations of a 1.75 MV, 375 kA, and 50 ns planar pinched-beam diode reveal that the strongest gigahertz-frequency oscillations in electric field and ion current arise from the dynamic motion of the magnetic null near the anode tip. These oscillations, which appear when the ion transit time becomes comparable to the local field-variation timescale, periodically expand the effective anode–cathode gap and generate bursts of over-accelerated ions. The resulting ion energy spectrum broadens substantially near the null while maintaining excellent beam uniformity along the anode. The simulations, therefore, demonstrate a direct physical linkage between ion transit time instability and magnetic null displacement, providing a mechanistic explanation for late-time spectral broadening in planar diodes and identifying new pathways for controlling beam quality through magnetic-topology management.
Source Publication
Physics of Plasmas (ISSN 1070-664X | eISSN 1089-7674)
Recommended Citation
J. Foster, S. Swanekamp, P. Ottinger; Dynamic magnetic null behavior in planar ion diodes: Particle-in-cell analysis of field oscillations and ion beam dynamics. Phys. Plasmas 1 March 2026; 33 (3): 033105. https://doi.org/10.1063/5.0314940
Comments
© 2026 The Authors.
This article is published by the American Institute of Physics (AIP), licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Sourced from the published version of record, as cited below.