Measurement of photoionization cross sections of the excited states of titanium, cobalt, and nickel

Abstract

Resonance-enhanced multiphoton ionization (REMPI) of Ti, Co, and Ni atoms has been investigated in the 285–320 nm region. We couple a laser-ablated metal target into a molecular beam to produce atoms. Ions produced from photoionization of the neutral atoms are monitored by a home-built time-of-flight mass spectrometer. Photoionization cross sections of the excited states of Ti, Co, and Ni were deduced from the dependence of the ion signal intensity on the laser intensity for photon energies close to the ionization threshold. The values obtained range from 0.2 to 6.0 Mb. No significant isotope dependence was found from measurements of the photoionization cross sections of T46i, T47i, T48i, N58i, and N60i.