Impact Of Laser Pulse Research Articles

Copper cluster ions in photon-induced field ionization mass spectra

Photon-induced field evaporation of copper emitters yields ionic species such as Cu 2+, Cu +, Cu 2 +, Cu 3 +, Cu 4 +, and copper oxide ions. The ions are formed during the impact of laser pulses of wavelength 337 or 600 nm, energy density in the range 0.1–1 J pulse −1 cm −2, 5-ns pulse length and 50-Hz repetition rate, and tip base temperatures between 80 and 300 K. Mass analysis was performed by time-of-flight measurements. The formation of clusters is due to a sudden temperature rise at high electric fields.