Rutherford backscattering spectrometry
![Left: Expected results: alpha particles passing through the plum pudding model of the atom undisturbed.
Right: Observed results: a small portion of the particles were deflected, indicating a small, concentrated positive charge.](/Images/godic/202502/08/Geiger-Marsden_experiment_expectation_and_result.svg3808.png")
![A single stage 2 MeV linear Van de Graaff particle accelerator, here opened for maintenance](/Images/godic/202502/08/2mv_accelerator-MJC013808.jpg")
Rutherford backscattering spectrometry (RBS) is an analytical technique used in materials science. Sometimes referred to as high-energy ion scattering (HEIS) spectrometry, RBS is used to determine the structure and composition of materials by measuring the backscattering of a beam of high energy ions (typically protons or alpha particles) impinging on a sample.