TECHNIQUES FOR PRODUCTION OF ORTHOSILICATE SCINTILLATORS

该提案的目标是开发新的方法， 低成本生产高性能掺铈镥 氧正硅酸盐（LSO）结晶。 动机是， LSO是近几年来发现的最有前途的新制冷剂之一。 五十年来，x的重要性质的独特组合 和伽马射线光谱，即：高密度，快速衰减，大 相对于BGO的光产率。 LSO似乎是一个主要的候选人， 取代PET系统中的BGO。 然而，LSO的实际应用 受到与晶体生长有关的困难的阻碍（Czocharalski 方法）由于采用高温。在第一阶段工作期间， 建议我们将进行可行性研究，以表明创新 采用一种新的低温晶体生长技术的方法可以解决 这些问题具体任务包括制备镥 前体，以及极细晶粒的生长（对于光学 透明）多晶LSO和单晶LSO通过这些新的 技术. 这些样本将被彻底调查， 结晶度、化学计量和光学透明度。闪烁 将测量对500 keV伽马射线的特性和响应， 与通过直拉法生长的外购晶体相比。 同相 我们将优化生长技术并简化过程， 获得大容量、高性能和低成本的LSO蒸馏 特别适合PET探测器环的晶体。 建议的商业应用 到目前为止，LSO还没有商业化。 如果可用，其使用 将广泛应用于各种应用中， 性能提升，或实现全新的用途， 需要较高的计数率。 其中包括：PET，高能物理; 工业过程控制;环境监测;地球物理学;以及 空间仪器等，以及全新的固态应用 光电探测器，如APD和新的漂移探测器。

The goal of this proposal is to develop novel methods for high-yield, low-cost production of high performance cerium-doped lutetium oxyorthosilicate (LSO) scintillating crystals. The motivation is that LSO is amongst the most promising new scintillators discovered in almost five decades, with a unique combination of important properties for x and gamma-ray spectroscopy, namely: high density, fast decay, and large light yield relative to BGO. LSO seems to be a prime candidate to replace BGO in PET systems. However, the practical utilization of LSO is hindered by difficulties related to crystal growth (Czocharalski method) due to the high temperatures employed. During the Phase I effort proposed we will perform a feasibility study to show that the innovative approach using a new low-temperature crystal growth technology can solve these problems. Specific tasks include preparation of lutetium precursors, and growth of both extremely fine grained (for optical transparency) polycrystalline LSO, and single crystal LSO via these new techniques. These samples will be thoroughly investigated for crystallinity, stochiometry and optical transparency. Scintillation properties and response to 500 keV gamma-rays will be measured and compared with bought crystals grown by the Czochralski method. In Phase II we will optimize the growth technique and streamline the process to obtain large volume, high performance and low cost LSO scintillating crystals specifically suited for PET detector rings. PROPOSED COMMERCIAL APPLICATION To date LSO is still not commercially available. When available its use will be widespread in hosts of applications leading to immediate performance gains, or enabling completely new uses where fast-timing or high counting-rate is needed. These include: PET,; high-energy physics; industrial process control; environmental monitoring; geophysics; and space instrumentation etc., as well as brand new uses with solid-state photodectectors such as APD s and new drift detectors.