Electric quadrupole refocusing of CaBr: Differential transmission of hyperfine levels and assignment of low-J lines in optical spectra

Abstract

Abstract The refocusing of a molecular beam of CaBr X 2 Σ + by an electric quadrupole is investigated. The enhancement by electric deflection of the intensities of lines originating from levels of low J in the fluorescence excitation spectrum of CaBr B 2 Σ + −X 2 Σ + is shown to be a useful technique of line assignment in a dense electronic band system. It is also found that the hyperfine levels are not transmitted equally through the quadrupole; for f levels, the hyperfine populations are actually reversed. A qualitative explanation, based on the correlation of zero-field hyperfine levels with high-field states, is given.