Three-dimensional particle-in-cell simulations of applied-[ital B] ion diodes

Journal Article · Mon Jan 31 23:00:00 EST 1994 · Physics of Plasmas; (United States)

DOI:https://doi.org/10.1063/1.870844· OSTI ID:5200200

Pointon, T D; Desjarlais, M P; Seidel, D B; Slutz, S A; Coats, R S; Kiefer, M L; Quintenz, J P ^[1]

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1. Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

The three-dimensional particle-in-cell code QUICKSILVER [Seidel [ital et] [ital al]., [ital Computational] [ital Physics], edited by A. Tenner (World Scientific, Singapore, 1991), p. 475] has been used to study applied-[ital B] ion diodes. The impedance behavior of the diode in these simulations is in good agreement with both analytic theory and experiments at peak power. The simulations also demonstrate the existence of electromagnetic instabilities which induce divergence in the ion beam. Early in time, there is an instability at high frequency relative to the ion transit time [tau][sub [ital i]], and the resulting beam divergence is low. However, later in time, the system makes a transition to an instability with a frequency close to 1/[tau][sub [ital i]], and the ion beam divergence rises to an unacceptably high value. The transition is associated with the build-up of electron space charge in the diode, and the resulting increase in the beam current density enhancement ([ital J]/[ital J][sub CL]). Using different schemes to inhibit the electron evolution, the transition has both been postponed and permanently eliminated, resulting in Li[sup +1] ion beams with a sustained divergence of [similar to]10 mrad at an energy of [similar to]10 MeV.

• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5200200
• Journal Information: Physics of Plasmas; (United States), Journal Name: Physics of Plasmas; (United States) Vol. 1:2; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

661220* -- Particle Beam Production & Handling
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BEAM DYNAMICS
BEAMS
CHARGED PARTICLES
COMPUTER CODES
CONFINEMENT
CURRENT DENSITY
DIODE TUBES
ELECTRON TUBES
INERTIAL CONFINEMENT
INSTABILITY
ION BEAMS
IONS
LITHIUM IONS
PLASMA CONFINEMENT
SIMULATION
SPACE CHARGE
THREE-DIMENSIONAL CALCULATIONS
Ta
Targets-- (1992-)