Real Time Extremity Dosimetry

目前的四肢剂量学可分为两类(A)集成材料(“胶片”标记等)。以及(B)事件计数或电子监测，它使用半导体传感器来测量电离辐射(例如。图1)。前者现在主要是热致发光剂量计(TLD)，它包含一层薄薄的灵敏氟化锂粉末。热致发光材料存储从电离辐射中吸收的能量，直到它们被加热(在这种情况下，加热到大约250摄氏度)，然后能量以光的形式释放。释放的光量与辐射剂量成正比。在被监测者使用规定的时间(几周到几个月)后，剂量计被送去处理。这种类型的系统的主要缺点是，直到事件发生后才能检测到突然的高剂量，并且不一定与特定事件相关。电子剂量计可以克服这一主要限制，但现有的商用系统有其自身的问题，其中一些是：(A)传感器的尺寸(&gt；30 mm长)意味着它们不能舒适地佩戴在四肢(如手指)上，并干扰工作人员增加暴露剂量的灵巧性，(B)它们遭受机械振动，产生虚假的瞬时剂量率，以及(C)它们具有依赖于剂量率的非线性响应。市场似乎准备好了一种新型传感器，它可以克服这些主要问题，并提供更好的性能。我们的商业想法是开发化合物半导体传感器来提高四肢剂量监测的质量。

Current extremity dosimetry can be divided into two classes (a) integrating material ("film" badges etc.) and (b) event counting or electronic monitoring which uses semiconductor sensors to measure the ionising radiation (eg. Figure 1 ). The former are now predominately themoluminescence dosimeters (TLD) which contain a thin layer of sensitive lithium fluoride powder. Thermoluminescent materials store the energy absorbed from ionising radiation until they are heated (in this case to about 250C), when the energy is released as light. The amount of light released is proportional to the radiation dose. After a prescribed period of use by the monitored person (weeks to months) the dosimeters are sent for processing. The major disadvantage of this type of system is that sudden high doses are not detected until after the event and cannot necessarily be correlated with a particular incident. Electronic dosimeters can overcome this major limitation, but the existing commercially available systems have their own problems, some of which are: (a) the size of the sensors (>30 mm long) means that they cannot be worn comfortably on the extremities (e.g. fingers) and interfere with the dexterity of the worker increasing the exposed dose, (b) they suffer from mechanic vibration giving false instantaneous dose rates and (c) they have a non-linear response dependent on dose rate.The market appears ready for a new type of sensor which can overcome these major issues and offer improved performance.Our business idea is to develop compound semiconductor sensors to improve the quality of extremity dose monitoring.