LSO Ceramics: A New Scintillator for Medical Radiography

描述(由申请人提供)： 我们计划对由LSO：Ce组成的陶瓷闪烁体进行研究和开发。众所周知，晶体LSO在光输出和定时方面是性能最高的闪烁体之一。只有一个障碍阻碍了LSO在大多数医疗应用领域占据主导地位：其高得令人无法接受的成本，这主要是由于生长晶体所需的非常高的温度，因此好晶体的产量非常低(高光输出和没有余辉)。 在第一阶段证明了LSO陶瓷是可以制造的，它具有与LSO晶体相当的效率和衰减时间，同时具有较少余辉的前景，我们希望开始一个优化材料的计划。其中一个关键的方面是将半透明提高到至少另一种广泛使用的闪烁体，即GOS陶瓷的透明度。这一目标将通过控制陶瓷的微观结构来实现，这涉及到促进颗粒生长的方法。 我们相信，LSO陶瓷将适用于目前主要使用LSO晶体的PET成像，从而大大降低成本。此外，我们相信，陶瓷将在CT中得到应用，目前CT的速度增长受到Cd钨酸盐和/或GOS较长衰变时间的限制。

DESCRIPTION (provided by applicant): We propose to conduct research and development towards a ceramic scintillator composed of LSO:Ce. It is well known that crystalline LSO is one of the highest performance scintillators in terms of light output and timing. Only one impediment stands in the way of LSO assuming a commanding position in most areas of medical applications: its unacceptably high cost, which is due largely to the very high temperatures necessary to grow the crystals and consequently the very low yield of good crystals (high light output and no afterglow). Having demonstrated in Phase I that an LSO ceramic can be made and that it has an efficiency and decay time comparable to LSO crystals, while carrying the promise of less afterglow, we wish to embark on a program of optimizing the material. One of the essential aspects is to increase the translucency to at least that of another widely used scintillator, namely GOS ceramic. This goal will be achieved through a control of the microstructure of the ceramic, involving methods, which will promote grain growth. We believe that the LSO ceramic will be appropriate in PET imaging, which now primarily uses LSO crystals, resulting in greatly reduced cost. Furthermore we believe that the ceramic will find applications in CT, where increase in speed is currently limited by the longer decay times of Cd tungstate and/or GOS.