REGENERATIVE TURBINE CYCLOTRON TARGETRY FOR F-18 PET

描述（由申请人提供）： 正电子发射断层扫描（PET）是一种用于诊断/分期/重新分期七种Medicare报销癌症类型的代谢成像模式。目前，美国医院和配送中心的96台回旋加速器用质子轰击稳定的浓缩O-18水靶，以产生F-18氟离子，用于合成F-18氟脱氧葡萄糖（FDG），每年用于350，000次PET扫描。CTI、EBCO、GE和IBA市场上的回旋加速器在10-20 Mev范围内，他们的工程师不断改进离子源和提取，以增加可用的束流。EBCO以19 MeV（3.8 kW）的能量将200微安的质子轰击在靶上。IBA正在mA范围内进行“自提取”。我们试图证明我们的再生式涡轮机（RT）再循环靶发明的可行性，以适应2 kW以上的束功率，允许FDG生产超过三倍。我们的系统的核心是一个小容量（约2 cc）的微型再生涡轮机，它每分钟泵送数升的高压目标水通过目标和一个小容量的热交换器。通过靶束撞击的渡越时间小于一毫秒，允许靶水在达到沸点之前离开时吸收几千瓦的热量。目的1是建立和机械测试一个新的银涡轮机泵，这是一个悬臂式泵轴的设计与水润滑陶瓷轴承，密封能够在5000转/分和500磅/平方英寸。成功的性能标准是能够以2 I/m的压力再循环500 psig的水，压力上升30 psig。目的2是在回旋加速器DI系统的温度和压力下构造和测试用二次水冷却的微型热交换器。它将被供给一个2升/米的430华氏度的水源，压力为500磅/平方英寸（模拟目标的输出），水源是通过使水流过一个2千瓦的管状电加热元件周围的环形空间而产生的。成功的性能将消除2千瓦的热量，出口温度低于100华氏度。目标3是将泵和热交换器连接到用于束流测试的t cc银靶体。成功的标准将是使用天然水在40微安的27 MeV质子（1.04千瓦）下实现稳定运行。第二阶段将使用O-18靶水进行F-18产额实验，将靶/热交换器/泵设计成一个紧凑的整体组件，以减少压降和总体积，并在能够超过2千瓦束功率的加速器上测试原型整体系统。

DESCRIPTION (provided by applicant): Positron Emission Tomography (PET) is a metabolic imaging modality used to diagnosis/stage/restage seven Medicare-reimbursed cancer types. Ninety six cyclotrons in US hospitals and distribution centers currently bombard stable enriched O-18 water targets with protons to produce F-18 fluoride ion for synthesis of F-18 fluorodeoxyglucose (FDG) used in 350,000 PET scans per year. CTI, EBCO, GE, and IBA market cyclotrons in the 10-20 Mev range, and their engineers are constantly improving ion sources and extraction to increase available beam. EBCO advertises 200 microamps of protons on target at 19 MeV (3.8 kW). IBA is working on "self-extraction" in the mA range. We seek to demonstrate feasibility of our regenerative turbine (RT) recirculating target invention to accommodate beam power above 2 kW, allowing FDG production to more than triple. The heart of our system is a low-volume (about 2 cc) miniature regenerative turbine, which pumps liters per minute of high-pressure target water through the target and a low-volume heat exchanger. Transit time through the target beam strike is less than a millisecond, allowing target water to absorb several kW of heat while exiting before reaching the boiling point. Aim 1 is to build and mechanically test a new Ag turbine pump, which is designed with a cantilevered pump shaft fitted with a water-lubricated ceramic bearing, and a seal capable of operating at 5000 rpm and 500 psig. Successful performance criteria will be the ability to recirculate 500psig water at 2 I/m with a pressure rise of 30 psig. Aim 2 is to construct and test a miniature heat exchanger cooled with secondary water at the temperature and pressure of the cyclotron DI system. It will be fed with a 2 I/m source of 430F water at 500 psig (simulating the output of a target) produced by flowing water through an annulus surrounding a 2 Kw tubular electric heating element. Successful performance will be removing 2 kW of heat with an exit temperature of less 100F. Aim 3 will be the connection of the pump and heat exchanger to a t cc silver target body for beam tests. Successful criteria will be achieving steady operation at 40 microamps of 27 MeV protons (1.04 kW) using natural water. Phase II will address F-18 yield experiments using O-18 target water, designing the target/heat exchanger/pump into a compact integral assembly to reduce pressure drops and total volume, and beta testing prototype integral systems at accelerators capable of greater than 2 kW beam power.