激光感生荧光法测量金属原子蒸气横向速度分布

Measurement of crosswise velocity distribution of metal atomic vapor by LIF

了解原子蒸气的密度、速度和温度分布对提高原子法激光分离同位素 (AVL IS)的分离效率起着重要作用。该实验采用激光感生荧光法和高灵敏度的线阵 CCD测量了线源蒸发钆金属原子蒸气的横向速度分布。通过实验证实了在线源蒸发的情况下 ,原子蒸气横向平均速度随横轴线性增加 ,横向速度分布近似服从 Maxwell分布。离蒸发对称面越远横向速度分布的半宽度越大 ,这表明离蒸发对称面越远原子热运动越激烈。而原子束横向平均速度随电子枪加热功率增加而增加 ,并且趋向于一饱和值。这是由于原子束平均速度取决于蒸发表面的温度 ,而液面温度随电子枪功率增加是有限的。

The density, velocity and temperature distributions of the metal atomic vapor must be known to improve the AVLIS (Atomic Vapor Laser Isotope Separation) separation efficiency. The crosswise velocity distribution of Gd metal atomic vapor heated by the linear electronic gun was measured using dye laser induced fluorescence and a high photosensitivity CCD array. The experiments show that the average crosswise velocity of the metal atomic vapor increases linearly along the x axis and the crosswise velocity distribution approximately obeys the Maxwell distribution law. The half width of the velocity distribution increases with the distance from the x z plane because the atomic thermal velocity increases with the distance. The mean crosswise velocity gradually increases with the power of the electronic gun and tends to be saturated because the mean velocity is a function of the liquid surface temperature and the surface temperature heated by the electronic gun is limited.