Accession Number:

ADA639613

Title:

Cleaning Techniques for Applied-B Ion Diodes

Descriptive Note:

Corporate Author:

SANDIA NATIONAL LABS ALBUQUERQUE NM

Report Date:

1995-07-01

Pagination or Media Count:

10.0

Abstract:

Measurements and theoretical considerations indicate that the lithium-fluoride LiF lithium ion source operates by electron-assisted field-desorption, and provides a pure lithium beam for 10-20 ns. Evidence on both the SABRE 1 TW and PBFA-II 20 TW accelerators indicates that the lithium beam is replaced by a beam of protons, and carbon resulting from electron thermal desorption of hydrocarbon surface and bulk contamination with subsequent avalanche ionization. Appearance of contaminant ions in the beam is accompanied by rapid impedance collapse, possibly resulting from loss of magnetic insulation in the rapidly expanding and ionizing neutral layer. Electrode surface and source substrate cleaning techniques are being developed on the SABRE accelerator to reduce beam contamination, plasma formation, and impedance collapse. We have increased lithium current density a factor of 3 and lithium energy a factor of 5 through a combination of in-situ surface and substrate cleaning, impermeable substrate coatings, and field profile modifications.

Subject Categories:

  • Electrical and Electronic Equipment
  • Manufacturing and Industrial Engineering and Control of Production Systems
  • Particle Accelerators

Distribution Statement:

APPROVED FOR PUBLIC RELEASE