摘要
X线的实效能通常由半价层和吸收物质的吸收系数来决定的,半价层则是由X线衰减一半时的吸收物质的厚度而获得的。在本项研究中,使用了两种型号的A1板作为吸收物质,其中一种A1板的型号为已知的,而另一种则不知,当后一种(未知型号)的A1板被用作吸收物质时,如果能获得一种有参考价值的计算和校定方法则是有意义的。本项研究我们使用电离箱式剂量计测得已知A1的半价层值来校正用热释光剂量计(简称TLD)测得的未知A1的半阶层值,结果发现了一种新的简便的测量半价层的方法。
Effective energy of X-ray is generally caiculated by use of half value layer and absorpting coefficient of the absorbing material. Half value layer of an absorbing material is obtained by measuring its thickness at which the dose of incident X-ray is reduced by 50%. At this study, aluminium of two kind were used as the absorbing material for the measurement of half value layer. The quality of one material widely useci for experiments was known, while that of the other material was not known. When the latter material is to be used as absorbing material. it would be useful if any reference value is given and a calibration method is established. Here, reference aluminium and calibration methods were experimentally investigated. As a thermoluminescence dosimeter was used at this study, calibration method to obtain the vaiuse for an ionization chamber was also investigated. As the result. we could develop new simple and practical system for the measurement of half value layer of an absorbing material whose aluminium is not known.
出处
《泰山医学院学报》
CAS
1993年第2期95-99,共5页
Journal of Taishan Medical College
关键词
半价层
吸收系数
X线诊断机
half value layer
absorpting coefficient
absorbing material
thermoluminescence dosimeter
ionization chamber
