Aeschliman D P, Hill R A
Appl Opt. 1972 Jan 1;11(1):148-52. doi: 10.1364/AO.11.000148.
A novel method of determining both the Doppler and Stark shifts in a single measurement of spectral lines emitted by the arc-heated flow from a plasma jet has been successfully demonstrated. The method uses a spherical mirror arranged with its optical axis coincident with the optical axis of a Fabry-Perot interferometer and with its center of curvature at the center line of the flow. The common optical axis lies at an angle to the flow. With this system, both red-and blue-shifted line profiles are recorded in the same spectral scan. If conditions are such that the red-and blue-shifted profiles are not resolvable, the blue-shifted component is chopped so that the recorded signal consists of the envelopes of both the red-shifted profile and the superimposed red-and blue-shifted profiles. The wavelength difference between the blue-and red-shifted line profiles is exactly twice the Doppler shift integrated along a line of sight through the flow and is independent of a Stark shift. The Stark shift is given by the wavelength difference between the absolute line center and the midpoint of the red-and blue-shifted lines. Abel inversion of integrated line shift data has yielded radial velocity profiles to an accuracy of +/-3% in a supersonic, arc-heated argon flow.
一种在单次测量由等离子体射流产生的电弧加热流所发射光谱线时同时测定多普勒频移和斯塔克频移的新方法已得到成功验证。该方法使用一个球面镜，其光轴与法布里 - 珀罗干涉仪的光轴重合，且其曲率中心位于流的中心线处。公共光轴与流成一定角度。利用该系统，在同一次光谱扫描中记录红移和蓝移的谱线轮廓。如果条件使得红移和蓝移的轮廓无法分辨，则对蓝移分量进行斩波，以便记录的信号由红移轮廓以及叠加的红移和蓝移轮廓的包络组成。蓝移和红移谱线轮廓之间的波长差恰好是沿穿过流的视线方向积分的多普勒频移的两倍，且与斯塔克频移无关。斯塔克频移由绝对谱线中心与红移和蓝移谱线中点之间的波长差给出。在超声速电弧加热氩气流中，对线移积分数据进行阿贝尔反演已得到径向速度分布，其精度达到±3%。
