Physikalisch-Technische Bundesanstalt, Braunschweig, Germany.
Phys Med Biol. 2021 May 24;66(11). doi: 10.1088/1361-6560/abfbb2.
This work presents a comprehensive catalog of x-ray spectra measured from x-ray tubes with tungsten, molybdenum, and rhodium anodes generated at tube potentials between 10 and 50 kV in steps of 1 kV. They can serve as an input for dose calculations, image quality calculations, investigations of detector features, and validations of computational spectral models, among other things. The measurements are performed by means of a high-purity germanium detector-based spectrometer 1 m from the x-ray sources without any added filtration. The x-ray tubes are characterized by thin beryllium exit windows (0.15-4 mm); thus, for energies above 15 keV, the spectra recorded can be considered approximately unfiltered. This allows potential users of the catalog to computationally add any filter to the spectra in order to create special radiation qualities of their choice. To validate this option, a small number of spectra are recorded with filter materials in place whose purity and thickness are known with high precision. These spectra are compared to the corresponding spectra from the catalog obtained by means of computationally added filters. The two types of spectra agree extremely well. Several typical mammographic radiation qualities are selected to compare the spectra obtained from the catalog presented here with corresponding spectra obtained from other catalogs published by Boone(19971863-74) and Hernandez(20172148-60). In contrast to the work presented here, those spectra rely partly or fully on calculations. A quantitative comparison is made by means of typical x-ray quality descriptors such as the mean energy and the first and second half-value layer. The results obtained from the Boone catalog match those of the current catalog sufficiently well for the Mo- and Rh-anode-based spectra. However, significant differences up to 10 times the estimated uncertainties are found for the quality descriptors evaluated from the spectra of Hernandezand the W-anode based spectra of Boone
本工作提供了一份涵盖钨、钼和铑阳极的 X 射线管在 10 至 50kV 管电压范围内以 1kV 为步长测量的 X 射线光谱的综合目录。它们可以作为剂量计算、图像质量计算、探测器特性研究以及计算光谱模型验证等的输入。这些测量是通过距 X 射线源 1 米的高纯锗探测器光谱仪进行的，没有任何额外的过滤。X 射线管的特点是薄的铍出射窗（0.15-4mm）；因此，对于能量高于 15keV 的光谱，记录的光谱可以被认为是近似无过滤的。这使得目录的潜在用户能够在计算上将任何滤波器添加到光谱中，以创建他们选择的特殊辐射质量。为了验证此选项，记录了少量带有已知纯度和厚度的滤波器材料的光谱。将这些光谱与通过计算添加滤波器获得的目录中的相应光谱进行比较。两种类型的光谱非常吻合。选择几种典型的乳腺 X 射线辐射质量，将从这里提供的目录中获得的光谱与由 Boone（19971863-74）和 Hernandez（20172148-60）发表的其他目录中获得的相应光谱进行比较。与这里提出的工作相反，这些光谱部分或完全依赖于计算。通过典型的 X 射线质量描述符（如平均能量以及第一和第二半价层）进行定量比较。从 Boone 目录获得的结果与当前目录的 Mo 和 Rh 阳极基谱足够吻合。然而，从 Hernandez 和 Boone 的 W 阳极基谱评估的质量描述符中发现了高达 10 倍估计不确定性的显著差异
