高斯分布及截断和抽样

Cut Method and Sample Procedure for Gaussian Beam

详细推论了高斯分布的轴对称电子束的截断方法和确定截断因子的表达式。结果表明在截断因子为０．９时，电子束发射度等于均方根发射度的二倍，而当电子束发射度等于均方根发射度时，截断因子仅为０．５９。给出了四维坐标变量的几率密度函数公式，并简述了相应的抽样方法。

The cut method for Gussian beam having axisymmetry is discussed in detail and the expression for the cut factor is defined in this paper. It is shown that when the factor is equal to 0.9,the cut beam emittance is twice as large as its root mean square (rms) emittance and the factor is only equal to 0.59 if the cut beam emittance is equal to its rms emittance. The probability function for the four dimensional new variables are derived and the sample procedures for them are simply described as well.