The Hyperion-II radio-frequency oxygen ion source on the UCLA ims1290 ion microprobe: Beam characterization and applications in geochemistry and cosmochemistry

A radio-frequency plasma ion source, the Hyperion-II, has been commissioned on a CAMECA ims1290, a high resolution/high transmission secondary ion mass spectrometer at UCLA. Performance characteristics (e.g., beam density, spot size, etc.) of the primary oxygen beam are documented and application to isotopic analyses requiring high lateral resolution with high secondary ion transmission are described. The Hyperion source delivers on average 10 times and 6 times the current density delivered by the CAMECA duoplasmatron for O-16(-) and O-16(2)- beams, respectively. This significantly enhanced current density allows for reduction of the analytical spot size by at least a factor of three while maintaining the beam intensity, making it possible to perform isotopic measurements at smaller scales without sacrificing analytical precision. In addition, the smaller Hyperion beam spot size also reduces the crossover size and spherical aberrations in the secondary ion optics, thereby improving secondary ion transmission at mass resolving power of 3000-12,000 by 25-80% compared to that achieved with a duoplasmatron. (c) 2017 Elsevier B.V. All rights reserved.