一种简单的双曲线方程可精确地给出照射野从4(cm)×4(cm)到35(cm)×35(cm)的输出量,在250kup-8 Meu范围内精度优于+/-0.2％。并且在30cm深度以内所给出的深度剂量表,其误差为+/-0.2％。方程为:y=Y(0)-c/(x(0)+X)。这里,y=输出量,X=方野边长,通过测量三组不同野的输出量,就可得出Y(0),X(0),C的值。在以上关系式的基础上,笔者在IBM-PB/XT微机上用BASIC语言编辑的实用程 A simple hyperbolic equation gives exactly the output from 4 (cm) × 4 (cm) to 35 (cm) × 35 (cm) for the field of irradiation with accuracy better than the + / -0.2%. And the depth dose table given within a depth of 30 cm has an error of +/- 0.2%. The equation is: y = Y (0) -c / (x (0) + X). Here, y = output, X = square length, and the values ​​of Y (0), X (0), C can be obtained by measuring the output of three different fields. Based on the above relationship, the author in the IBM-PB / XT computer using BASIC language editor utility