纳秒激光诱导铜等离子体中原子激发态5s′~4D_（7/2）的瞬态特性研究

Instantaneous characteristics of excited atom state 5s′ ~4D_（7/2） in the copper plasma induced by laser

利用时间分辨光谱技术,研究了激光诱导Cu等离子体中激发态5s′4D7/2的形成及其辐射跃迁的瞬态特性.结果表明:在激发态5s′4D7/2原子的制备过程中,电子离子复合、粒子间碰撞机理在不同时刻分别起主导作用.激光峰值到达金属表面后500ns期间,粒子间的剧烈碰撞作用使得激发态5s′4D7/2主要通过向低能态4p′4F9o/2跃迁来转移能量.500ns以后,激发态5s′4D7/2通过以相同的概率辐射CuI465.11nm和CuI529.25nm特征谱线向低能态4p′4F9o/2和4p′4D7o/2转移能量.

The formation of excited atom state 5s′ D7/2 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′D7/2 at different tims during its evolvement. When the collisions among particles are severe,the excited atom state 5s′ D7/2 mainly transits to low energy atom state 4p′ 4F9o/2. 500 ns after the peak of laser pulse arriving at target surface,the excited state 5s′D7/2 transited to 4p′ 4F9o/2 and 4p′ 4D7/2 with the same probabilities by emitting lines CuI465. 11 nm and CuI529. 25 nm respectively.