No abstract

Time-resolved Fourier-transform spectroscopy was applied to the study of the emission spectra of Cu vapours in a vacuum (10 −2 Torr) produced in ablation of a Cu metal target by a high-repetition rate (1.0 kHz) pulsed nanosecond ArF laser (λ = 193 nm, output energy of 15 mJ). The time-resolved infrared emission spectrum of Cu was recorded in the 1800-3800 cm −1 spectral region with a resolution of 0.017 cm −1 . The time profiles of the measured lines have maxima at 18-20 μs after a laser shot and display non-exponential decay with a decay time of 5-15 μs. This study reports 17 lines (uncertainty 0.0003-0.018 cm −1 ) of Cu I not previously observed. This results in seven newly-found levels and revised energy values for 11 known levels (uncertainty 0.01-0.03 cm −1 ). We also calculate transition probabilities and oscillator strengths for several transitions involving the reported Cu levels.