Experimental methods available at the Laboratory of Nuclear Analytical Methods
Rutherford Backscattering Spectrometry
Rutherford Backscattering spectrometry (RBS) is most commonly used non-destructive nuclear analytical methods. RBS is widely used for study of thin layers and for study of multilayer systems with thickness from nm to µm. RBS is very suitable for elemental depth analysis. From such measurement it is possible to determine, with some limitations, both the atomic mass and concentration of elemental target constituents as a function of depth below the surface.
Elastic Recoil Detection Analysis and Time of Flight ERDA
Elastic Recoil Detection Analysis (ERDA) is a non-destructive nuclear analytical method. ERDA is a technique for depth profiling of light elements in thin layers and in multilayer systems. Measurement with this method may be performed on amorphous as well as crystalline materials. ERDA uses high energy (~1MeV/amu) heavy-ion beams to kinematically recoil and depth profile low atomic number target atoms. The heavy ion projectile only needs to have a greater mass than the target atom. Alpha particles are commonly used to obtain recoil spectrum for hydrogen and its isotopes.
RBS-channeling spectrometry - enables us to investigate crystalline materials. RBS channeling is based on channeling of charged particles in monocrystalline grid of sample. Path of ions that browse through crystals is reduced by crystalline grid. Most of incident ions is caught inside the channels from atoms string. These atoms are further dispersed inside channels on great angle. For RBS channeling are typical ion beams with 1-2MeV He+ ions that are suitable for good mass and depth resolution and small radiation damage.
PIXE, PIGE and PESA
Particle Induced X-Ray Spectroscopy (PIXE) is a very sensible non-destructive ion beam analytical method for elemental composition study. PIXE is very suitable for a study of area and bulk concentration of elements not for depth analysis. Basees for this method is that the high energetic proton beam excites, due to inner-shell ionization, the emission of characteristic X-rays from the sample atoms. Particle Induced Gamma-ray Spectroscopy (PIGE) is a versatile technique, which complements other ion beam techniques (especially PIXE) for sample analysis. It is the most common application of nuclear analysis. The PIGE method is mostly based on nuclear reactions (p, g), (p,p´g), (p, a g) induced by MeV protons, where prompt nuclear gamma-rays are produced. PIGE is very suitable for light elements analysis.
Basic idea of this method is focusing of a ion beam on the smallest dimension and scanning on the sample. Ion beam analytical methods are the same as with normal dimensions – classical ion beam methods (RBS, PIXE, PIGE). Ion micro-beam is versatile equipment that allows study of structures with resolution of microns. Compared to electron micro-beam have better detection limits and may study the trace quantity. Moreover one can use micro-beam for other application like proton writing.
Ion beam implantation
Ion beam implantation is a process when accelerated ions are shooting into the solid. This methods is optimal for change of physical, chemical, electric or optic properties of the solid. Ion beam implantation is capable of preparation of layers with high density and good defined depth profile and for change of crystalline structure of substrate.