测定了激光烧蚀Co等离子体中Co原子389.408 nm发射谱线的时间空间分辨发射光谱。由发射光谱线的强度和斯塔克(Stark)展宽计算了等离子体电子密度,并由实验结果讨论了激光等离子体中电子密度的时间空间演化特性。实验结果表明,当延时在100～1000 ns变化时,等离子体中的电子密度变化范围为0.02×1017～0.73×1017 cm-3,在沿激光束方向上,当距离靶表面0～1.8 mm范围内变化时,相应的电子密度ne范围为0.3×1017～0.8×1017 cm-3,等离子体电子密度在激光束方向上具有很好的对称性。

The time and spatial-resolved emission spectrum of Co atom 389.408 nm spectra line in laser induced Co plasma was measured. The electron density of plasmas was calculated from the measured intensity and Stark broadening of emission spectral line. The time and spatial evolution properties of the electron density were finally discussed. The measured results show that the plasma electron density is varied from 0.02×1017 to 0.73×1017 cm-3 when the time delay is in the range from 100 to 1000 ns. It is also concluded that the plasma electron density is varied from 0.3×1017cm-3 to 0.8×1017 cm-3 along the direction of the laser beam when the distance from target surface is in the range from 0 to 1.8 mm. The distribution of the plasma electron density along the laser beam has well symmetry.