Monte Carlo simulations for reconstruction of a linear 20 MV X-ray spectrum induction accelerator

• Published in: 中国物理C：英文版 Vol. 36; no. 9; pp. 861 - 866
• Main Author: 王毅 李勤 江孝国
• Format: Journal Article
• Language: English
• Published: 2012
• Subjects: X射线光谱; 直线感应加速器; 线性; 蒙特卡洛方法; 蒙特卡罗模拟; 衰减器; 频谱函数; 频谱计算
• ISSN: 1674-1137; 0254-3052

To study the spectrum reconstruction of the 20 MV X-ray generated by the Dragon-I linear induction accelerator, the Monte Carlo method is applied to simulate the attenuations of the X-ray in the attenuators of different thicknesses and thus provide the transmission data. As is known, the spectrum estimation from transmission data is an ill-conditioned problem. The method based on iterative perturbations is employed to derive the X-ray spectra, where initial guesses are used to start the process. This algorithm takes into account not only the minimization of the differences between the measured and the calculated transmissions but also the smoothness feature of the spectrum function. In this work, various filter materials are put to use as the attenuator, and the condition for an accurate and robust solution of the X-ray spectrum calculation is demonstrated. The influences of the scattering photons within different intervals of emergence angle on the X-ray spectrum reconstruction are also analyzed.