吸收谱线Doppler展宽对原子多步光电离的影响

发布时间：2018-01-06 07:25

本文关键词：吸收谱线Doppler展宽对原子多步光电离的影响　出处：《物理学报》2017年19期 　论文类型：期刊论文

【摘要】：原子法激光同位素分离的核心之一是如何高效地将原子激发电离.本文从原子法激光同位素分离的实际情况出发,研究了原子吸收谱线的Doppler展宽对原子电离率的影响.研究中使用的理论工具是原子激发电离的密度矩阵方程,并利用数值计算方法对方程进行求解.研究结果表明:当吸收谱线有Doppler展宽时,在激光参数不变的条件下原子电离率会降低;且当激光功率固定时,存在使原子电离率为最大的线宽值.这与已发表文献中无Doppler展宽时的计算结果有很大不同.为了追求最佳的原子电离效果,在原子法激光同位素分离系统中激光应该尽可能地工作在最佳线宽条件下.如果激光线宽有不可控的随机波动,在技术上让激光线宽略大于最佳线宽更为有利.无论如何控制激光线宽,尽可能地降低原子吸收谱线的Doppler展宽都有利于原子电离率的提高.
[Abstract]:One of the core of atomic laser isotope separation is how to excite and ionize atoms efficiently. This paper starts from the actual situation of atomic laser isotope separation. The influence of Doppler broadening of atomic absorption lines on atomic ionization rate is studied. The density matrix equation of atomic excitation ionization is used in this study. The numerical calculation method is used to solve the equation. The results show that the atomic ionization rate will decrease when the absorption line is widened by Doppler and the laser parameters are invariant. And when the laser power is fixed, there is a line width value which can make the ionization rate of the atom to be the maximum. This is very different from the calculated results without Doppler broadening in the published literature, in order to pursue the best atomic ionization effect. In the atomic laser isotope separation system, the laser should work under the optimal linewidth condition as far as possible, if the laser linewidth is uncontrollable random fluctuation. Technically it is more advantageous to make the laser linewidth slightly larger than the optimum linewidth. However controlling the laser linewidth and reducing the Doppler broadening of the atomic absorption spectrum as far as possible is beneficial to the increase of atomic ionization rate.
【作者单位】：清华大学工程物理系;核工业理化工程研究院;
【分类号】：O562.6
【正文快照】： 1 引言原子多步光电离是原子蒸汽激光同位素分离 (atom vapor laser isotope separation,AVLIS)中关键的一步,由于涉及目标同位素原子的提取率和分离选择性,国内外许多学者对此进行了理论I1-91和实验研究[1Q_141.在己有的理论研究中,原子通常被认为处于静止状态,即不考虑

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