NSF Arizona Accelerator Mass Spectrometry Facility: Operations and Research Applications

自1981年以来，一台使用2 MV通用Ionex串联粒子加速器的加速器质谱仪（AMS）一直在亚利桑那大学运行。这个AMS实验室的主要任务是双重的。它既是一个服务实验室，为整个科学界提供具有地球物理和考古重要性的样品的放射性碳（14c）测定，但也支持广泛的内部科学研究。目前，该实验室每年为来自世界各地的许多科学家分析3000多个样品的14c含量。目前将近一半的实验室分析是用于内部研究或与外部研究人员合作进行的研究。这样的内部研究集中在一系列不同的主题上。其中一些研究的方向是在样品的化学制备、仪器的改进和数据还原和解释方面改进AMS技术。实验室的努力使他们在14c分析中获得了前所未有的精度。他们目前能够生产l4C/l3C比率，测量精度为+0.5%，每个样品的计数时间约为30分钟，用于最新材料。据报道，该设备使用多个目标测定的高精度测量精度为+0.25%。其他内部研究项目面向更基础的科学目标，包括研究岩石和冰中14C的原位生产，以及使用树木年轮或珊瑚14cu - th测量来改进14C校准曲线。这笔拨款支持亚利桑那加速器质谱仪（AMS）实验室的运营和维护费用，并将使他们能够维持和提高科学界期望从该设施获得的AMS测量的高标准，并开发AMS的新应用，然后将其提供给科学界。作为这笔拨款的一部分，亚利桑那州将升级他们现有的AMS系统，包括一个带有静电分析仪的注入系统、一个高分辨率注入磁铁、一个快速同位素脉冲系统、一个带有静电四极透镜的高能分析系统、一个90度磁性分析仪和一个圆柱形静电分析仪。还包括对将于1996年3月在图森举行的下一届加速器质谱国际会议的支持。＊＊＊

9508413 Donahue An Accelerator Mass Spectrometer (AMS) using a 2 MV General Ionex tandem particle accelerator has been operated at the University of Arizona since 1981. The primary mission of this AMS laboratory is twofold. It operates as both a service laboratory to provide radiocarbon (l4C) determinations of samples of geophysical and archaeological importance to the scientific community at large, but also supports a wide range of in-house scientific research. The laboratory presently analyzes the l4C content of over 3,000 samples a year for many scientists from many parts of the world. Just under half of the current laboratory analyses are for in-house research, or for research undertaken in collaboration with external researchers. Such in-house research has focused on a diverse set of topics. Some of this research has been oriented toward improving AMS technology in terms of chemical preparation of samples, improvements to instrumentation and data reduction and interpretation. The labs efforts have enabled them to obtain unprecedented precision in l4C analyses. They currently are able to produce l4C/l3C ratios with measurement precisions of +0.5% in a counting time of about 30 minutes per sample, for recent material. High-precision measurements as accurate as +0.25% have been reported by this facility using multiple target determinations. Other in-house research projects are oriented towards more basic science goals including studies of in-situ production of 14C in rocks and ice and improvements to the l4C calibration curve using tree rings or coral l4CU-Th measurements. This grant supports operating and maintenance costs of the Arizona Accelerator Mass Spectrometer (AMS) laboratory and will allow them to maintain and improve the high standards of AMS measurements that the scientific community has come to expect from this facility, and to develop new applications of AMS, which will then be available to the scientific community. As part of this grant, Arizona will upgrade their existing AMS system with an injection system with an electrostatic analyzer, a high-resolution injection magnet, a fast isotope pulsing system, a high-energy analysis system with an electrostatic quadrupole lens, a 90 magnetic analyzer, and a cylindrical electrostatic analyzer. Support for the next International Conference on Accelerator Mass Spectrometry, to be held in Tucson in March 1996 is also included. ***