Ayotte Guylaine, Archambault Louis, Gingras Luc, Lacroix Frédéric, Beddar A Sam, Beaulieu Luc
Département de physique, de génie physique et d'optique, Université Laval, Quebec City, Quebec, Canada G1K7P4.
Med Phys. 2006 Sep;33(9):3519-25. doi: 10.1118/1.2256300.
One way to improve the performance of scintillation dosimeters is to increase the light-collection efficiency at the coupling interfaces of the detector system. We performed a detailed study of surface preparation of scintillating fibers and their coupling with clear optical fibers to minimize light loss and increase the amount of light collected. We analyzed fiber-surface polishing with aluminum oxide sheets, coating fibers with magnesium oxide, and the use of eight different coupling agents (air, three optical gels, an optical curing agent, ultraviolet light, cyanoacrylate glue, and acetone). We prepared 10 scintillating fiber and clear optical fiber light guide samples to test different coupling methods. To test the coupling, we first cut both the scintillating fiber and the clear optical fiber. Then, we cleaned and polished both ends of both fibers. Finally, we coupled the scintillating fiber with the clear optical fiber in either a polyethylene jacket or a V-grooved support depending on the coupling agent used. To produce more light, we used an ultraviolet lamp to stimulate scintillation. A typical series of similar couplings showed a standard deviation in light-collection efficiency of 10%. This can be explained by differences in the surface preparation quality and alignment of the scintillating fiber with the clear optical fiber. Absence of surface polishing reduced the light collection by approximately 40%, and application of magnesium oxide on the proximal end of the scintillating fiber increased the amount of light collected from the optical fiber by approximately 39%. Of the coupling agents, we obtained the best results using one of the optical gels. Because a large amount of the light produced inside a scintillator is usually lost, better light-collection efficiency will result in improved sensitivity.
提高闪烁剂量计性能的一种方法是提高探测器系统耦合界面处的光收集效率。我们对闪烁光纤的表面处理及其与透明光纤的耦合进行了详细研究，以尽量减少光损失并增加光收集量。我们分析了用氧化铝片对光纤表面进行抛光、用氧化镁对光纤进行涂层处理以及使用八种不同的耦合剂（空气、三种光学凝胶、一种光学固化剂、紫外线、氰基丙烯酸酯胶水和丙酮）的情况。我们制备了10个闪烁光纤和透明光纤光导样品来测试不同的耦合方法。为了测试耦合效果，我们首先切割闪烁光纤和透明光纤。然后，我们清洁并抛光两根光纤的两端。最后，根据所使用的耦合剂，将闪烁光纤与透明光纤在聚乙烯护套或V形槽支架中进行耦合。为了产生更多的光，我们使用紫外线灯来激发闪烁。一系列典型的类似耦合显示光收集效率的标准偏差为10%。这可以通过表面处理质量的差异以及闪烁光纤与透明光纤的对准情况来解释。不进行表面抛光会使光收集量减少约40%，而在闪烁光纤近端涂抹氧化镁会使从光纤收集到的光量增加约39%。在耦合剂中，我们使用其中一种光学凝胶获得了最佳结果。由于闪烁体内产生的大量光通常会损失，更好的光收集效率将导致灵敏度提高。
