在激光与物质相互作用的实验中，气体靶通常由超声速喷嘴在高背压下向真空中高速喷射气体产生。激光与气体靶相互作用时确定打靶条件对整个实验有着十分重要的意义。为了得到不同实验条件下气体靶密度的分布特性，采用马赫－曾德尔干涉法测量了气体靶密度分布，获取了干涉图样。使用基于傅里叶变换的条纹处理方法测得的干涉图样，得到不同实验条件下气体分子密度的全空间分布。实验表明：用M－Z干涉仪测量超声速气体喷嘴产生的气体靶密度分布十分有效。基于傅里叶变换的条纹处理方法具有精度高、实时性好的优点，为打靶时气体靶密度的实时测量提供了可能。

In laser-cluster interaction experiment,the gas target is usually generated by stuffing gas into vacuum chamber in high flow velocity via supersonic gas jet under the condition of very high backing pressure. To acquire the density distribution characteristics of the gas target in different experimental conditions,the density distribution of the gas target was measured with M-Z interferometry,and the fringes were obtained at different backing pressures,temperatures and time lapses. The total spatial distribution of gas molecular density under different experimental conditions was obtained via the interferometer pattern measured by Fourier transformation based fringe processing. The experiment shows that M-Z interferometer can effectively measure the gas target density distribution produced by the supersonic gas jet. The fringe processing method based on Fourier transformation is accurate and has real-time feature. Therefore,it provides the possibility for the real-time measurement of gas target density during targeting practice.