Introduction

The Noble Gas Isotope Laboratory (NGIL) was established in 1981 by Dr. Zafer Top at RSMAS as part of an effort to expand tracer measurement capability at the University of Miami. The facility consists of three noble-gas mass-spectrometers, associated vacuum inlet and processing lines, and other relevant measurement hardware. One of the objectives was to increase the national capability to measure oceanic tritium and helium isotopes, tracers that provide decadal time-scale information for the global ocean. The laboratory now provides helium isotope and tritium measurements as a service to other educational, government and commercial institutions, in addition to sponsored groundwater research.

The MAP-215 isotope mass spectrometer

Isotopes of noble gases are important tools in environmental and earth sciences. Their applications include investigations of transport and mixing processes in the atmosphere and ocean, determination of temporal trends in these processes, origin and flow of groundwater, investigation of rock-water interactions and palaeo-climatic studies. Mass-spectrometric tritium measurements are made by allowing tritium in water samples to decay radioactively into ³He, in a predetermined time interval. The precision of the method is 0.01TU or better, which gives much smaller uncertainties in the ³H-³He age determination. Additionally, the second objective was to provide measurement service to other institutions, with unrestricted funds. High precision helium isotope and neon measurements are routinely made; argon, krypton, xenon isotopes are measured as needed. The NGIL interacts closely with the Tritium Lab located in the same building.

Introduction The Noble Gas Isotope Laboratory (NGIL) was established in 1981 by Dr. Zafer Top at RSMAS as part of an effort to expand tracer measurement capability at the University of Miami. The facility consists of three noble-gas mass-spectrometers, associated vacuum inlet and processing lines, and other relevant measurement hardware. One of the objectives was to increase the national capability to measure oceanic tritium and helium isotopes, tracers that provide decadal time-scale information for the global ocean. The laboratory now provides helium isotope and tritium measurements as a service to other educational, government and commercial institutions, in addition to sponsored groundwater research. The MAP-215 isotope mass spectrometer Isotopes of noble gases are important tools in environmental and earth sciences. Their applications include investigations of transport and mixing processes in the atmosphere and ocean, determination of temporal trends in these processes, origin and flow of groundwater, investigation of rock-water interactions and palaeo-climatic studies. Mass-spectrometric tritium measurements are made by allowing tritium in water samples to decay radioactively into ³He, in a predetermined time interval. The precision of the method is 0.01TU or better, which gives much smaller uncertainties in the ³H-³He age determination. Additionally, the second objective was to provide measurement service to other institutions, with unrestricted funds. High precision helium isotope and neon measurements are routinely made; argon, krypton, xenon isotopes are measured as needed. The NGIL interacts closely with the Tritium Lab located in the same building.