A multipass, magnetically confined sputter source for absorption-based spectroscopy of transient molecules: the spectrum of NiH

Abstract A sputter source with characteristics well suited to absorption-based spectroscopies of unstable, reactive, and refractory molecules, such as transition metal monohydrides, is described. The molecular number density (10 10 cm −3 ) and active pathlength (20 cm times 40 passes) are sufficient for spectroscopies in which the signal is carried by the transmitted laser beam rather than induced fluorescence. Magnetic (