Accession Number:

ADA256070

Title:

Current Neutralization in Ballistic Transport of Light Ion Beams

Descriptive Note:

Interim rept.

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC

Report Date:

1992-10-01

Pagination or Media Count:

48.0

Abstract:

Intense light ion beams arc being considered as drivers to ignite fusion targets in the Laboratory Micro-fusion Facility LMF. Ballistic transport of these beams from the diode to the target is possible only if the beam current is almost completely neutralized by plasma currents. This paper summarizes related work on relativistic electron beam and heavy ion beam propagation and describes a simple simulation model DYNAPROP which has been modified to treat light ion beam propagation. DYNAPROP uses an envelope equation to treat beam dynamics and uses rate equations to describe plasma and conductivity generation. The model has been applied both to the high current, 30 MeV Li-3 beams for LMF as well as low current, 1.2 MeV proton beams which are currently being studied on GAMBLE II at the Naval Research Laboratory. The predicted ratio of net currents to beam current is -0.1-0.2 for the GAMBLE experiment and -0.01 for LMF. The implications of these results for LMF and the GAMBLE experiments are discussed in some detail. The simple resistive model in DYNAPROP has well-known limitations in the 1 torr regime which arise primarily from the neglect of plasma electron transport. Alternative methods for treating the plasma response arc discussed. Light ion beam fusion, Current neutralization, Ballistic transport.

Subject Categories:

  • Fusion Devices (Thermonuclear)
  • Particle Accelerators

Distribution Statement:

APPROVED FOR PUBLIC RELEASE