Experimental Improvement of 750-keV H- Beam Transport at LANSCE Accelerator Facility

TL;DR

This paper reports experimental studies on 750-keV H- beam transport at LANSCE, revealing space-charge neutralization effects and demonstrating improved beam transport with reduced losses through experimental and theoretical analysis.

Contribution

It provides new experimental data on space-charge neutralization timescales and demonstrates optimized beam transport in the LANSCE facility.

Findings

Significant variation in neutralized space charge dynamics along the beamline

Improved beam transport efficiency with reduced beam losses

Correlation between experimental data and theoretical models for optimization

Abstract

The 750-keV low-energy beam transport of the Los Alamos Neutron Science Center (LANSCE) linac consists of two independent beam lines that facilitate simultaneous injection of H+ and H- beams into the linear accelerator. The efficiency of beam transport within this structure is largely controlled by the effects of space-charge neutralization. In this paper, we report a series of experiments that were performed to determine the level, as well as the required timescale for the onset of beam space charge neutralization. Measurements performed along the structure indicate significant variation of neutralized space charge beam dynamics in the beamline, and the corresponding results have been used to substantially improve beam transport with diminished beam losses. The analysis of experimental and theoretical data employed in optimization of beam performance in the transport line is discussed.