Bissonnette J P, Schreiner L J
Department of Oncology (Radiation Oncology), McGill University, Montréal, Québec, Canada.
Med Phys. 1992 May-Jun;19(3):579-82. doi: 10.1118/1.596848.
Models for the computer generation of tungsten target x-ray spectra proposed by Birch and Marshall [Phys. Med. Biol. 24, 505-517 (1979)] and recently by Tucker, Barnes, and Chakraborty [Med. Phys. 18 211-218 (1991)] are compared. Some basic differences in the equations for the number of bremsstrahlung photons of different energies in the spectra are discussed. The models are compared in terms of their ability to characterize x-ray spectra from constant potential clinical units using three parameter equivalent spectra (EQSPEC) determined from the fit of model generated transmission curves through aluminum to measured data. The Kramers model for x-ray generation is included for completeness. It is shown that two of the models generate very similar x-ray spectra from given transmission curves although the fitting parameters in the EQSPEC characterization differ.
对Birch和Marshall[《物理医学与生物学》24, 505 - 517(1979)]以及最近Tucker、Barnes和Chakraborty[《医学物理》18, 211 - 218(1991)]提出的用于计算机生成钨靶X射线光谱的模型进行了比较。讨论了光谱中不同能量轫致辐射光子数方程的一些基本差异。根据使用通过将模型生成的透过铝的传输曲线拟合到测量数据确定的三参数等效光谱(EQSPEC)来表征来自恒压临床装置的X射线光谱的能力，对这些模型进行了比较。为了完整性，纳入了用于X射线生成的克莱默斯模型。结果表明，尽管EQSPEC表征中的拟合参数不同，但其中两个模型从给定的传输曲线生成非常相似的X射线光谱。
