The purpose of this work was to characterize the stem-effect signal and the Cerenkov light ratio (CLR) in various light guides as functions of measurement geometry and magnetic field strength. Two PMMA-, two silica-, and one polystyrene-based light guides were considered in this work. Spectra measurements were performed as functions of depth, fiber-beam angle, and magnetic field strength using an optical spectrometer. All measurements were performed using a clinical linear accelerator at a nominal photon beam energy of 6 MV. Depths ranging from 1 cm to 10 cm, fiber-beam angles ranging from 90 degrees to 30 degrees, and magnetic field strengths ranging from 0 T to ± 1.40 T were investigated. The CLR was calculated from each spectrum by taking the ratio of the integral signal between 400 nm and 500 nm to the integral signal between 500 nm and 600 nm. A maximum increase of 80.5% in the stem-effect signal was observed in the magnetic field. Variations in spectral shape and, conseque...

中文翻译：

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技术说明：用于闪烁剂量法的光导中的光谱变化与测量几何形状和磁场强度的关系表征

这项工作的目的是根据测量几何形状和磁场强度来表征各种光导中的干效应信号和切伦科夫光比（CLR）。在这项工作中考虑了两种基于PMMA，两种二氧化硅和一种基于聚苯乙烯的光导。使用光学光谱仪，根据深度，纤维束角度和磁场强度进行光谱测量。使用临床线性加速器以6 MV的标称光子束能量执行所有测量。研究了1 cm至10 cm的深度，90度至30度的纤维束角度以及0 T至±1.40 T的磁场强度。通过取400 nm至500 nm之间的积分信号与500 nm至600 nm之间的积分信号之比，从每个光谱中计算CLR。在磁场中，茎效应信号最大增加了80.5％。光谱形状的变化以及征服...