磁约束技术对激光诱导等离子体辐射特性的影响

为了提高激光诱导击穿光谱质量,利用Nd:YAG激光器烧蚀土壤样品,研究了磁场作用下的激光诱导等离子体辐射特性。实验结果表明,在相同激光输出能量条件下,随着磁场强度的增大,等离子体的辐射强度逐渐增强。计算可知,当采用的磁场强度为0.5T时,样品元素Al,Fe,Ba和Ti的光谱线强度比无磁场作用时的分别增强了52.35%,46.64%,64.01%和51.73%,光谱信噪比分别提高了45.44%,69.64%,40.26%和41.33%;而等离子体的电子温度和电子密度分别提高了1 355.01K和0.53×1016cm-3。可见,利用磁场约束等离子体的技术是提高激光光谱质量的一种有效方法。

Effect of magnetic confinement technique on plasma radiation characteristics

To improve the quality of laser-induced breakdown spectroscopy, the effects of magnetic confinement on plasma were studied, which was excited by Nd: YAG laser. The experimental results show that plasma radiation intensity increased with increasing magnetic field under the same laser energy. By calculating, we can see that the spectral line intensity of Al, Ba, Fe and Ti increased about 52.35%, 46.64%, 64.01% and 51.73% under 0.5 T magnetic field, the spectral signal-to-noise ratio increased about 45.44%, 69.64%, 40.26% and 41.33%, while the electron temperature and electron density of plasma was heightened by 1 355.01 K and 0.53×10¹⁶ cm^-3, respectively, as compared to those with no magnetic confinement. It is clear that using magnetic confinement is an effective measure for the enhancement of spectrum quality.