Simpkin D J
Health Phys. 1987 Sep;53(3):267-79. doi: 10.1097/00004032-198709000-00006.
Shielding requirements for mammography installations have been investigated. To apply the methodologies of NCRP Report No. 49, the scatter-to-incident ratio of a typical mammography beam was measured, and the broad beam transmission was calculated for several representative beam spectra. These calculations were found to compare favorably with published low kVp tungsten-targeted x-ray transmission through a variety of shielding materials. Radiation shielding tables were developed from the calculated transmissions through Pb, concrete, gypsum, steel, plate glass, and water, using a technique which eliminates the "add one HVL" rule. It is concluded that Mo-targeted x-ray beams operated at 35 kVp require half the shielding of W-targeted beams operated at 50 kVp, and that adequate, cost-effective shielding calculations will consider alternatives to Pb.
已对乳腺摄影设备的屏蔽要求进行了研究。为应用美国国家辐射防护与测量委员会第49号报告的方法，测量了典型乳腺摄影束的散射与入射比，并针对几种代表性的束谱计算了宽束传输。结果发现，这些计算结果与已发表的低千伏峰值钨靶X射线通过各种屏蔽材料的传输情况相比具有优势。利用一种消除“加一个半价层”规则的技术，根据通过铅、混凝土、石膏、钢、平板玻璃和水的计算传输结果制定了辐射屏蔽表。得出的结论是，在35千伏峰值下运行的钼靶X射线束所需的屏蔽量是在50千伏峰值下运行的钨靶束的一半，并且充分且具有成本效益的屏蔽计算将考虑铅的替代材料。
