【摘要】 屏蔽设计的最优化需要确定α值。本文对若干放射治疗室及 x 射线探伤室的屏蔽墙外表面的照射量率作了测定与计算,从而根据该屏蔽的透过曲线计算了这些已建设备的α值。这些α值变化于20—1000元（人·mSv）^-1的范围内。也指出了不合理的设计。文中还讨论了在实际计算中使用差分法所带来的误差。更多还原

【Abstract】 Theαvalues for shielding wall in some radiation therapy rooms and X-ray defectoscopy rooms have been evaluated,throngh the measured（and calculated）exposure rates outside the shielding wall,and the transmission curve of the shields.The α values of these existing installations vary widely in the range of 20—1000 Yuan.（person·mS_v）^-1.Difference between differential analysis and difference analysis is discussed.更多还原