skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Design and characterization of a neutralized-transport experiment for heavy-ion fusion

Journal Article · · Physical Review Special Topics - Accelerator and Beams

In heavy-ion inertial-confinement fusion systems, intense beams of ions must be transported from the exit of the final focus magnet system through the fusion chamber to hit millimeter-sized spots on the target. Effective plasma neutralization of intense ion beams in this final transport is essential for a heavy-ion fusion power plant to be economically competitive. The physics of neutralized drift has been studied extensively with particle-in-cell simulations. To provide quantitative comparisons of theoretical predictions with experiment, the Virtual National Laboratory for Heavy Ion Fusion has completed the construction and has begun experimentation with the Neutralized Transport Experiment (NTX). The experiment consists of three main sections, each with its own physics issues. The injector is designed to generate a very high-brightness, space-charge-dominated potassium beam while still allowing variable perveance by a beam aperturing technique. The magnetic-focusing section, consisting of four pulsed magnetic quadrupoles, permits the study of beam tuning, as well as the effects of phase space dilution due to higher-order nonlinear fields. In the final section, the converging ion beam exiting the magnetic section is transported through a drift region with plasma sources for beam neutralization, and the final spot size is measured under various conditions of neutralization. In this paper, we discuss the design and characterization of the three sections in detail and present initial results from the experiment.

Research Organization:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Director. Office of Science. Office of Fusion Energy Sciences, Lawrence Livermore National Laboratory Contract W-7405-ENG-48, Princeton Plasma Physics Laboratory Contract DE-FG-0295ER40919 (US)
DOE Contract Number:
AC03-76SF00098
OSTI ID:
832759
Report Number(s):
LBNL-53928; HIFAN 1276; R&D Project: Z46010; TRN: US200516%%1145
Journal Information:
Physical Review Special Topics - Accelerator and Beams, Vol. 7; Other Information: Journal Publication Date: 2004; PBD: 14 Mar 2004
Country of Publication:
United States
Language:
English