Scattering of protons from helium

The main work described in this thesis, is the original calculation of the excitation of helium by proton and of electron - capture process from helium by proton where the 2nd order potential introduced by Bransden & Coleman (1972)has been applied. It begins with a discussion of the existing methods relevant to the present work and followed by the construction of a second - order potential. A critical survey of the previous work has also been presented and its relation to the present work and result is discussed. The cross-sections for the following processes is calculated in the energy - range indicated (i) p + He(1S(^2)) →H(^+)(lS,2S,2p) + He(lS(^2)) 25 Kev - 500 Kev (ii) p + He(lS(^2))→H (IS) + He(^+)(IS) 30 Kev - 10 Mev The calculated cross - section along with existing results has also been presented and it is seen that the present method provides better results for the excitation process, but for the charge - exchange process, our results do not agree with the results of the experiment at high energies.