Instantaneous characteristics of excited atom state 5s′ 4D7/2 in the copper plasma induced by laser

The formation of excited atom state 5s' D-7/2 and its transition process in the copper plasma induced by nanosecond pulse laser are studied by the time-resolved spectrum technology. The experimental results indicate the recombination of electron and ion and the collisions among particles each play a dominent role in forming excited atom state 5s' D-7/2 at different tims during its evolvement. When the collisions among particles are severe, the excited atom state 5s' D-7/2 mainly transits to low energy atom state 4p' F-4(9/2)o. 500 ns after the peak of laser pulse arriving at target surface, the excited state 5s' D-7/2 transited to 4p' F-4(9/2)o and 4p' D-4(7/2) with the same probabilities by emitting lines CuI465. 11 nm and CuI529. 25 nm respectively.