was developed quite far by Williams from 1929 to 1945. Williams devised a theory, which consists of fitting the Multiple Scattering distribution as a Gaussian-like portion due to small scattering angles and the single collision tail due to the large angles. William, E.J., studied beta particle straggling, Multiple scattering of fast electrons and alpha particles, and cloud curvature tracks due to scattering to explain Multiple scattering in different scenario and he proposed a mean projection deflection occurrence due to scattering. His theory later extended to multiple scattering of alpha particles. Goudsmit and Saunderson provided a more complete treatment of Multiple Scattering, including large angles. For large angles Goudsmit considered series of Legendre polynomials which are numerically evaluated for distribution of scattering. The angular distribution from Coulomb scattering has been studied in detail by Molière.,(Molière:1948) and further continued by Marion and coworkers. Marion, J.B., and Young, F.C., in their Nuclear Reaction Analysis provided Tabular information regarding energy loss of charged particles in matter, Multiple scattering of charged particles, Range straggling of protons, deuterons and alpha particles, equilibrium charge states of ions in solids and energies of elastically scattered particles. Scott presents a complete review of basic theory, Mathematical methods, as well as results and applications. A comparative development of Multiple Scattering at small angles is presented by Meyer, based on a classical calculation of single cross section. Sigmund and Winterbon reevaluated Meyer’s calculation to extend it to a more general case. Marwick and Sigmund carried out development on lateral spreading by Multiple Scattering, which resulted in a simple scaling relation with the angular distribution. Applications HI-ERDA and LI-ERDA have similar applications. As mentioned previously, the only difference between the two techniques is energy of the source used for the bombardment of the sample. ERDA, in general, has many applications in the areas of polymer science, material science – semiconductor materials, electronics, and thin film characterization. ERDA is widely used in polymer science. This is because polymers are hydrogen-rich materials which can be easily studied by LI-ERDA. One can examine surface properties of polymers, polymer blends and evolution of polymer composition induced by irradiation. HI-ERDA can also be used in the field of new materials processed for microelectronics and opto-electronic applications. Moreover, elemental analysis and depth profiling in thin film can also be performed using ERDA. An example of how ERDA can be used by scientists is shown below. In one of