Generation of lithium negative ions in a volume source with optical pumping

摘要

An experiment is described in which a high density of lithium negative ions (1times;1010cmminus;3) is generated by dissociative attachment of electrons to optically pumped lithium molecules in a supersonic expansion. During a 3hyphen;mgr;s period up to 7percnt; of electrons are attached. A measurement of the lithium vibrational temperature is also reported. Theoretical aspects of Liminus;production in both a static multicusp source and a supersonic beam source are discussed. The optical pumping requirements for a continuous Liminus;supersonic beam source are derived.