OPTICAL CERAMIC SCINTILLATORS FOR DIGITAL RADIOGRAPHY

本项目的目标是开发一种基于激活透明光学陶瓷技术的用于数字牙科摄影的高性能X射线探测器。进展远远超过了我们的第一阶段目标，生产出了完全致密的TOC，其CCDS测量的光输出与CSI：TL持平。我们还开发了一种将这种材料像素化的激光技术，实现了121p/mm的20%的MTF，分辨率是Gd2O2S：Tb屏幕的两倍。第二阶段将涉及三个关键领域：我们将通过确定最佳陶瓷成分和处理来最大化光输出，并特别关注开发商业上可行的合成技术。我们将改进像素化工艺，以刻蚀50微米正方形像素阵列，凹槽宽度不超过2.5微米，纵横比至少为50：1，以达到至少90%的屏幕填充因子，并开发一种适合大规模生产的速度实现这一目标的系统。我们将在实际生活条件下制造、测试和评估原型单元。这些成果将为二期产业开发奠定坚实的基础。拟议的商业应用：由于目前可用的X射线荧光屏不能提供必要的空间分辨率，医学放射成像一直无法充分挖掘数字技术的数据采集和处理潜力。能够满足这一需求的材料的开发将使放射学技术发生革命性变化，并极大地提高其诊断能力。眼下的市场不仅包括整个牙科社区，还包括其他放射成像技术，如体层摄影术，并有可能扩展到目前使用的几乎每一台X光机。

The objective of this program is to develop a superior X-ray detector for digital dental radiography, based on the technology of activated transparent optical ceramics. Progress has far exceeded our Phase I goals, producing a fully dense TOC whose light output as measured by CCDs is on a par with CsI:Tl. We have also developed a laser technique for pixelating this material, achieving an MTF at 12 1p/mm of 20%, a resolution twice as good as a Gd2O2S:Tb screen. Phase II will address three critical areas: We will maximize the light output by defining the optimal ceramic composition and treatment, with special attention to developing a commercially viable synthesis technique. We will improve the pixelization process so as to etch an array of 50 microm square pixels separated by grooves no more than 2.5 microm wide and an aspect ratio of at least 50:1, so as to reach a screen fill factor of at least 90%, and develop a system for achieving this at a speed appropriate for large-scale production. And we will fabricate, test, and evaluate prototype units under real life conditions. These results will form a solid foundation for Phase II industrial exploitation. PROPOSED COMMERCIAL APPLICATION: Because currently available X-ray phosphor screens cannot provide the necessary spatial resolution, medical radiography has been unable to tap the full potential of digital techniques for data acquisition and processing. The development of a material that can fill this need will revolutionize radiological techniques and greatly enhance their diagnostic power. The immediate market includes not only the entire dental community, but also other radiographic imaging such as tomography, and potentially extends to virtually every X-ray machine now in use.