Amplification in light-induced reaction of Cu with Cl in the 2 VUV

A non-selective light-induced reaction was observed in the spectral range from 135 to 120 nm due to electronic excitation of Cl in the gas phase to the 1Sq and 212 u Squ states. It reaches a quantum efficiency of reacted Cu per impinging photon of 174 and the underlying amplification process has an efficiency of 4=106. A selective reaction dominates between 135 and 200 nm with two prominent bands at 170 and 144 nm. It originates from a bulk-excitation with a quantum efficiency of two reacted atoms per photon. q2000 Elsevier Science B.V. All rights reserved.