利用YAG激光(波长1.06μm，脉宽为10 ns)烧蚀Al靶产生的三条Al Ⅲ等离子体谱线(452.92 nm，451.25 nm，415.01 nm)，在局部热力学平衡近似下，利用玻尔兹曼图，测定了等离子体电子温度在不同激光能量下的变化特性。随着激光能量的增加，电子温度从14800 K近似单调的上升到20000 K，随后反而有所下降。在电子温度达最高时，连续辐射谱强度并未达最大值。同时还观测到，Al的原子谱线和离子谱线强度随激光能量有不同的变化特点。利用玻尔兹曼图的最小二乘方拟合，测得Al Ⅲ谱线447.99 nm(4f2F7/2-5g2G9/2)跃迁的几率约为(10.4士0.8)×108s-1。
The temperature of laser-produced Al plasmas (LPP) have been measured at different laser energy by using the model of local thermodynamic equilibrium (LTE). The electron temperature changed from 14800 K to 20000 K when the laser energy increased from 30 mJ/pulse to 45 mJ/pulse, then , the temperature had some decrease along the laser energy increasing. The intensities of Al Ⅰ spectra lines have shown similar variant property, but differetnt from other Al ions spectra lines. Meanwhile, the transition probability of 447.99 nm line of Al Ⅲ was measured by the Boltzmann plots was about (9～10)× 108 s-1.
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