Principle of Rutherford Backscattering Spectroscopy

MeV cm ). The technique is used to determine atomic mass and concentration of the constituents of an elemental target as a function of depth below the surface i.e., concentration profile of trace elements which are heavier than the major constituents of the substrate. The schematic diagram shown in Fig. 2.7 illustrates the principle of the RBS technique. 

The energy Ei of the scattered particle, given by (2.13), is written in terms of the scattering angle as 

The relation between energy separation (AEi) of any projectile energy and mass difference of target elements (AM2) is given by 

This relation indicates that the mass resolution 5M2 (1) decreases with increase of projectile energy Eq (2) decreases for heavier elements M2 and (3) light elements may overlap with thick layers of the substrate of heavier elements. 

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