Development and Application of a Scanning Ion Microprobe.
Abstract
A complete scanning ion microprobe system was developed for use in the Naval Academy Tandem Accelerator Laboratory. The microprobe employs a computer-controlled positioner to scan a sample while it is bombarded with a finely focused particle beam. The beam excites characteristic X rays from the sample atoms. The X-ray yields are converted to elemental concentrations. The concentration and position data are then used to create two dimensional surface concentration maps, which are analogous to microscope views of the sample. The microprobe was tested using a 200-mesh transmission electron microscope grid. The diameter of the beam spot on the sample surface was found to be approximately 30 micrometers. The capabilities of the microprobe were demonstrated by measuring the positional variation of elemental concentrations in several inclusions of the Allende meteorite. These inclusions are thought to predate the formation of the solar system. Extensive position dependent concentration data may eventually provide information on the formation mechanisms and temperature and radiation history of meteorites. jg p.5
Document Details
- Document Type
- Technical Report
- Publication Date
- May 09, 1995
- Accession Number
- ADA299350
Entities
People
- Bernard T. Meehan
Organizations
- United States Naval Academy