论文部分内容阅读
本文的目的是对一些稀土硫氧化物X射线屏作一个综合的比较。报导了(Y_2O_2S:Tb,La_2O_2S:Tb和Gd_2O_2S:Tb)在与普通的X光底片以及与实验的(对绿色灵敏)X光底片一起使用时的相对速度和分辨本领。所实验的稀土硫氧化物屏与市售的CaWO_4 屏的性能也作了比较。对于分辨本领差不多的屏,La_2O_2S:Tb和Gd_2O_2S:Tb比YO_2S:Tb和CaWO_4 的速度快得多。La_2O_2S:Tb在管电压低于90kvp时较好。在90kvp以上 Gd_2O_2S:Tb最好。这些特性是同屏的量子利用率有关的。量子利用率被定义为入射在屏上的X射线能量被屏实际吸收的份额。计算了硫氧化物和CaWO_4 屏的量子利用率。
The purpose of this article is to make a comprehensive comparison of some rare earth oxysulfides X-ray screens. The relative speed and resolving power of (Y_2O_2S: Tb, La_2O_2S: Tb and Gd_2O_2S: Tb) for use with conventional X-ray films and with experimental (for green-sensitive) X-ray films are reported. The properties of the tested rare earth oxysulfide screen and the commercially available CaWO_4 screen are also compared. For the same resolution screen, La 2 O 2 S: Tb and Gd 2 O 2 S: Tb are much faster than YO 2 S: Tb and CaWO 4. La 2 O 2 S: Tb is better when the tube voltage is lower than 90kvp. Above 90kvp Gd_2O_2S: Tb is best. These characteristics are related to the quantum efficiency of the screen. Quantum utilization is defined as the fraction of X-ray energy incident on the screen that is actually absorbed by the screen. Quantum utilization of sulfur oxides and CaWO_4 screens was calculated.