Thursday, October 2, 2008
2008 R&D 100 Winner
Time-of-flight mass spectrometers, which are used in atomic probes, use the transit time for ions to determine the mass-to-charge ratio for the ion, which gives the atomic composition. The mass resolution is improved with a reflectron. However, reflectrons deal poorly with large angle spreads unless they are excessively large. The angle problem is worsened by chromatic aberration.
The LEAP 3000X HR from Imago Scientific Instruments Corp., Madison, Wisc., avoids this problem by adopting a 3-D shape, instead of a series of planar ring electrodes, as is usual. The time taken for an ion to travel through the atom probe, including the time spent in the reflectron, is independent of the initial energy of the ion. Known as time focusing, this improves the mass resolution of the spectrometer without introducing chromatic aberration. Imago’s large area reflectron improves the mass resolution by six times while maintaining a large 43° field of view. This allows researchers to better understand a material’s atomic scale features in the context of its metallurgical nanostructure. In addition, the LEAP makes locating nanostructures of interest much easier: often only one specimen run is needed to find features such as grain boundaries. Finally, the LEAP is ideal for the detection and quantification of dilute species.
Technology
Imaging device
Developers
Imago Scientific Instruments Corp.
