The energy dependence of the total cross-sections for ionization by positron impact has been measured for He, Ne, Ar, CO2 and O2. The interplay between this and other scattering channels has been investigated. The data for He, Ne and Ar has been interpreted using a combination of R-matrix and threshold theories in the neighbourhood of the Ps formation threshold. In CO2, an enhancement of the Ps formation probability is found when the remnant ion is left in an excited state. In O2, structure has been observed which indicates channel-coupling with excitation to the Schumann-Runge continuum.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics
- Condensed Matter Physics
- Physical and Theoretical Chemistry