HR: 09:45h
AN: V41E-08    [Abstracts]
TI: A New Multi Collector Isotope Ratio Mass Spectrometer
AU: * Appelhans, A D
EM: anthony.appelhans@inl.gov
AF: Idaho National Laboratory, POB 1625, Idaho Falls, ID 83415, United States
AU: Olson, J E
EM: john.olson@inl.gov
AF: Idaho National Laboratory, POB 1625, Idaho Falls, ID 83415, United States
AU: Ward, M B
EM: michael.ward@inl.gov
AF: Idaho National Laboratory, POB 1625, Idaho Falls, ID 83415, United States
AU: Dahl, D A
EM: da@dahl.myrf.net
AB: With the goal of improving the sensitivity of isotope ratio measurements, particularly for actinides, a new magnetic sector mass spectrometer that utilizes up to seven full-sized discrete dynode electron multipliers operating simultaneously has been designed, constructed and is in the early stages of testing. The design is based on a newly developed ion dispersion lens that enables the mass dispersed individual isotope beams to be separated by 35 mm; this allows a full-sized discrete dynode pulse counting multiplier to be used for each beam. The ion dispersion lens (US patents 6,297,501 and pending) is a two element electrostatic 90 degree sector device that causes the beam-to-beam dispersion to increase faster than the intra-beam dispersion. Each of the multipliers is housed in an isolated case and is equipped with a deflector/condenser lens at the entrance to optimize pulse generation. The instrument includes a 9-sample filament cartridge mounted on a micro-manipulator X-Y stage that enables adjustment of the filament position with 10 micron resolution within the ion lens. Initial testing has shown that the instrument is performing as predicted by the ion optics model of the design.
DE: 1120 Isotopic disequilibrium dating
DE: 1194 Instruments and techniques
DE: 8494 Instruments and techniques
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2007 Fall Meeting