ION BEAM METHODS

The main ion-beam methods in the lab are RBS, ERDA,PIXE and NRA where the energy of the scattered or ejected ions and emitted X-rays or g-rays is measured, respectively, after hitting the sample with the ion beam. The method names are abbreviations derived from their full names:

  • PIXE - Proton Induced X-ray Emission. This is very similar to PIGE method (Proton Induced Gamma ray Emission) where the sample analysis is done by looking at the Gamma rays, a product of nuclear reactions in the target, excited by the ion beam.
  • NRA - Nuclear Reaction Analyses. It is based on detection of products from nuclear reactions induced by MeV projectiles (protons, He, or other). In the case of detection of gammarays the NRA is usually called PIGE.
  • RBS - Rutherford Back Scattering. Here we measure the energy of the projectiles, backscattered from the sample. The depth profile elemental concentrations can be determined from these spectra of the target elements heavier than the projectile. In the modern version of the method the energy spectrum is measured by Time-Of-Flight of the backscattered projectiles (RBS-TOF) instead of with the surface barrier detector.
  • ERDA - Elastic Recoil Detection Analysis. Here we measure the energy spectrum of ions, ejected from the target. That way one can efficiently determine depth profiles of concentrations of the light target elements. The method is especially suitable for hydrogen. Much better results are obtained by measuring simultaneously the energy and linear momentum of the ejected ions because then one can separate the layers of different elements in the energy spectrum (ERDA-TOF). This is accomplished again by measuring Time-Of-Flight of the ejected ions before they hit the energy detector.
  • STIM - Scanning Transmission Ion Microscopy. This ion beam method is suitable for the thin samples (biological samples, for example) where the ion projectiles penetrate the target. By the energy analysis of the ions, scattered for a small angle the data about the structure and target composition is obtained.
  • FSS - Forward Scattering Spectroscopy.
  • SEA - Secondary Electron Analysis.
  • IBIC - Ion Beam Induced Charge. This method can be used for analysis of active areas in the microelectronic devices.





Last updated: 01/22/2014