Several microbeam analysis techniques for solids are available, which couple a microbeam ionization source with mass spectrometric detection. Secondary ion mass spectrometry (SIMS) is based on the principle that an energetic primary ion beam can sputter and ionize atoms from the surface of a specimen. Then, the secondary ions are detected in a mass spectrometer. Two types of SIMS instruments are available: (1) a secondary ion microscope and microprobe that uses a magnetic-sector mass spectrometer and special ion optics to produce either a direct, mass-resolved microscope image or a scanned microprobe image of the sample surface; and (2) a state-of-the-art time-of-flight secondary ion microprobe that incorporates a choice of several pulsed ion guns combined with a time-of-flight mass spectrometer to obtain complete mass-spectral coverage and secondary ion images with submicrometer spatial resolution. The SIMS method can be applied to problems in materials science, semiconductor technology, organic coatings, biology, environmental sciences, particle analyses, and forensic sciences. Additionally, two more techniques are available: atmospheric mass spectrometry (AMS) and ion mobility spectrometry (IMS) that provide capabilities to analyze materials held at atmospheric pressure. Analysis at atmospheric pressure is especially useful for biological samples and forensic applications. Opportunities are also available to study secondary ion emission processes, and to conduct instrumental research to improve the capabilities of these techniques.

 

key words

Mass spectra; Secondary ion mass spectra; Ion mobility spectrometry; Atmospheric mass spectrometry;

Citizenship:  Open to U.S. citizens

Level:  Open to Postdoctoral applicants