Optical Ceramic Hafnates: New Fast PET Scintillator

描述（由申请人提供）： 我们建议进行研究和开发的一种新的陶瓷闪烁体的基础上铈激活的钡的Hamate（BaHfO 3：-Ce），锶的HfO 3：-Ce），和镥的HfO 3（Lu 2 Hf 2 O 7：Ce）。该开发计划是由于认识到目前只有一种闪烁体满足PET成像的需求，即LSO。虽然在许多方面都很出色，但LSO价格昂贵，无法广泛使用，而且质量差异很大。该晶体具有比LSO更高的阻止本领，大约相同的衰减时间，并且是立方的（或接近立方的），是用于制造完全透明的光学陶瓷的候选者。这种发展的主要优点是成本低得多（陶瓷形成比单晶生长便宜得多），并且由于制造温度低得多，可能提高产量。该计划将利用我们在陶瓷制冷机方面的丰富经验。 第一阶段的结果非常令人鼓舞。陶瓷样品已被制造，显示光输出（在X射线激发下）与LSO，20 - 50 ns的特征衰减，和显着的半透明。这些性能将通过开发合适的方法来合成前驱体粉末和优化陶瓷形成过程来改善。这是所提出的工作的本质，这应该导致一个上级替代探测器的PET。

DESCRIPTION (provided by applicant): We propose to conduct research and development of a new ceramic scintillator based on cerium-activated barium hamate (BaHfO3:-Ce), strontium hafnate (SrHfO3:-Ce), and lutetium hafnate (Lu2Hf2O7:Ce). The development program is prompted by the realization that there is presently only one scintillator that fulfills the needs of PET imaging, namely LSO. While in many ways remarkable, LSO is expensive, it is not widely available and it varies greatly in quality. The hafnates have higher stopping power than LSO, about the same decay time and, being cubic (or nearly cubic), are candidates for fabrication as perfectly transparent optical ceramics. The main advantages of such a development would be much lower cost (ceramic formation is far less expensive than single crystal growth), and possibly improved yield due to much lower fabrication temperatures. The program would take advantage of our extensive experience in ceramic scintillators. The results of Phase I are very encouraging. Ceramic specimens have been fabricated that display light output (under X-ray excitation) comparable to LSO, characteristic decay of 20 - 50 ns, and remarkable translucency. All these properties will be improved by developing the proper procedures to synthesize the precursor powders and optimize the ceramic formation process. This is the essence of the proposed work, which should result in a superior alternative detector for PET.