OPTICAL CERAMIC SCINTILLATORS FOR DIGITAL RADIOGRAPHY

本项目的目标是基于活化透明光学陶瓷技术，开发一种用于数字牙科放射照相的高级x射线探测器。目前的进展已经远远超过了第一阶段的目标，生产出了一种完全致密的TOC，通过ccd测量，其光输出与CsI:Tl相当。我们还开发了一种用于这种材料像素化的激光技术，实现了121p /mm的MTF，分辨率为20%，是Gd2O2S:Tb屏幕的两倍。第二阶段将解决三个关键领域：我们将通过定义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，以蚀刻50微米平方像素的阵列，以不超过2.5微米宽的凹槽分隔，长宽比至少为50:1，从而达到至少90%的屏幕填充系数，并以适合大规模生产的速度开发实现这一目标的系统。我们将在现实生活条件下制造、测试和评估原型单元。这些成果将为二期产业化开发奠定坚实的基础。拟议的商业应用：由于目前可用的x射线荧光粉屏幕不能提供必要的空间分辨率，医学放射照相一直无法充分挖掘数字技术在数据采集和处理方面的潜力。能够满足这一需求的材料的开发将彻底改变放射技术，并大大提高其诊断能力。直接的市场不仅包括整个牙科社区，还包括其他放射成像，如断层扫描，并有可能扩展到现在使用的几乎所有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.