Particle-in-cell simulations of electron beam control using an inductive current divider

Journal Article · Wed Nov 18 00:00:00 EST 2015 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4935893· OSTI ID:1238584

Swanekamp, S. B.  ^[1]; Angus, J. R. ^[1]; Cooperstein, G. ^[1]; Ottinger, P. F.  ^[1]; Richardson, A. S. ^[1]; Schumer, J. W.  ^[1]; Weber, B. V. ^[1]

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1. Naval Research Lab. (NRL), Washington, DC (United States)

Kinetic, time-dependent, electromagnetic, particle-in-cell simulations of the inductive current divider are presented. The inductive current divider is a passive method for controlling the trajectory of an intense, hollow electron beam using a vacuum structure that inductively splits the beam’s return current. The current divider concept was proposed and studied theoretically in a previous publication [Phys. Plasmas 22, 023107 (2015)] A central post carries a portion of the return current (I₁) while the outer conductor carries the remainder (I₂) with the injected beam current given by I_b=I₁+I₂. The simulations are in agreement with the theory which predicts that the total force on the beam trajectory is proportional to (I₂-I₁) and the force on the beam envelope is proportional to I_b. For a fixed central post, the beam trajectory is controlled by varying the outer conductor radius which changes the inductance in the return-current path. The simulations show that the beam emittance is approximately constant as the beam propagates through the current divider to the target. As a result, independent control over both the current density and the beam angle at the target is possible by choosing the appropriate return-current geometry.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Office of Defense Science (NA-113)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1238584
• Report Number(s): SAND-2015-7836J; PHPAEN; 603700
• Journal Information: Physics of Plasmas, Vol. 22, Issue 11; ISSN 1070-664X
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

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