Silicon carbide: a new positron moderator

Abstract

Observation of copious positron re-emission from crystalline 6H-SiC, with no pre-treatment and without the need for ultra-high-vacuum conditions, suggests that this material may form the basis of an important new moderator for the production of monoenergetic positrons. Its positron work function is measured to be eV. Its electrical characteristics point to SiC as a prime candidate for development as a field-assisted positron moderator, producing moderately intense slow-positron beams in laboratory-based systems and enabling a new generation of positron experimentation.