Reconstruction of 4-MV bremsstrahlung spectra from measured transmission data.
Reconstruction of 4-MV bremsstrahlung spectra from measured transmission data.
复制标题
根据测得的透射数据重建 4-MV 轫致辐射谱。
DOI：
10.1118/1.595356
复制
发表时间：
1983
期刊：
影响因子：
3.8
通讯作者：
B. Bjärngard
中科院分区：
文献类型：
--
作者：
Pin‐Hua Huang;Kenneth R. Kase;B. Bjärngard
用铅和铝的组合衰减器测量了4 MV韧致辐射束的透射数据。从这些数据中，原始的能谱已被重建使用迭代最小二乘法，以前通过模拟研究评估。三个类似的4 MV直线加速器的中心轴上的光谱没有显着差异。当研究偏离中心轴5度和9度的光谱时，9度的光谱显示出预期的低能光子增加。所有这些光谱显示最大光子能量为4.5 +/- 0.2 MeV。当磁控管功率降低时，中心轴上的光谱向较低能量移动，最大光子能量降低到3.5 +/- 0.2 MeV。本实验研究的结果证实了从以前的刺激的结论，即用于分析传输数据的数值技术可以准确地表示4 MV韧致辐射谱，并检测能量分布的差异与机器调谐和位置的变化在辐射场的4 MV韧致辐射束。
Transmission data for 4-MV bremsstrahlung beams have been measured with a combination of lead and aluminum attenuators. From these data, the original energy spectra have been reconstructed using an iterative least-squares technique, previously evaluated by simulation studies. The spectra on the central axis for three similar 4-MV linear accelerators indicated no significant differences. When studying the spectra at 5 degrees and 9 degrees off the central axis, that at 9 degrees showed the expected increase of low-energy photons. All these spectra showed a maximum photon energy of 4.5 +/- 0.2 MeV. When the magnetron power was reduced, the spectrum on the central axis shifted to lower energies and the maximum photon energy decreased to 3.5 +/- 0.2 MeV. The result of this experimental study confirms the conclusions from the previous stimulation, that the numerical technique for analysis of transmission data can accurately represent 4-MV bremsstrahlung spectra and detect differences in energy distribution with changes in machine tuning and position in the radiation field for a 4-MV bremsstrahlung beam.