Accession Number : ADA338900

Title :   H(-) and D(-) Scaling Laws for Penning Surface-Plasma Sources

Corporate Author : LOS ALAMOS NATIONAL LAB NM APPLIED THEORETICAL PHYSICS DIV

Personal Author(s) : Smith, H. V., Jr. ; Allison, Paul ; Sherman, Joseph D.

PDF Url : ADA338900

Report Date : 27 SEP 1993

Pagination or Media Count : 28

Abstract : The small-angle source (SAS), 4X source, and 8X source are Penning surface-plasma sources (SPS) that produce high-current, high-brightness H(-) ion beams for accelerator applications. The scaling from the SAS (1X source) to the 4X source, and from the 4X source to the 8X source is at least as good as predicted by the scaling laws. In many instances, the scaling is better than predicted, particularly in the critical area of the efficiency with which H(-) ions are produced per unit of discharge power. Using Z = jH(-)/Fc, where Fc is the cathode power load, Z(4X) approx. equals to 2Z(SAS) and Z(8X) approx. equals to 1.5Z(4X). The jH(-) scaling is at least as good as predicted by the scaling laws - we have been able to produce the predicted H(-) current in both the 4X and the 8X sources. The SAS was scaled up in size to the 4X source, and the 4X source was scaled up in size to the 8X source, on the assumption that the effective kTH(-) = 5 eV. These temperature scalings appear to be obeyed. We also assumed that kTH(-) = kTD(-) and jD(-) = jH(-)/square root of 2. The temperature scaling appears to be obeyed, and the D(-) current scaling appears to be even better than assumed, namely JD(-) approx. equals to JH(-).

Descriptors :   *ION BEAMS, *PLASMA GENERATORS, *PLASMA ACCELERATORS, PLASMAS(PHYSICS), CURRENT DENSITY, GAS DISCHARGES, ION DENSITY, ION ACCELERATORS.

Subject Categories : Particle Accelerators
      Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE