The VUV Absorption Spectra of SiF and SiF

Abstract The absorption spectrum of a microwave discharge (2450 MHz) in flowing helium with traces of SiF 4 has been recorded on the SA61 beam line of SUPERACO between 2000 and 500 A. Two new ionization energies have been observed at 15.12 and 17.27 eV corresponding, respectively, to the A 1 Π and B 1 Σ + states of SiF + . The A 1 Π ← X 1 Σ + transition of the ion has been identified for the first time on high-resolution spectra obtained in 1992 with the 35-foot Eagle spectrograph in Meudon.