Iris Publishers Material Science Open Access Journal

Positron Impact Excitation of the nS, nP, and nD States of Atomic Hydrogen Material Science Introduction The well-known relativistic wave equation was formulated in 1928 by Dirac [1]. He combined the ideas of relativity and quantum mechanics to formulate the equation and predicted an antiparticle of spin ħ/2. He assumed that the antiparticle must be a proton because at that time only two particles namely proton and electron were known. However, Hermann Weyl, from symmetry consideration, suggested that the positive particle must have the same mass as that of an electron. Later on, this particle came to be known as a positron. The positron was discovered in cosmic rays by Anderson [2] in a cloud chamber in 1932. Positrons and electrons can form positronium atoms which annihilates giving a 511 MeV line with a width of 1.6 keV. This line has been seen from the center of galaxy. Positrons have been detected on the sun, stars, and in the interstellar medium [3]. They have been used in medi...

Positron Impact Excitation of the nS, nP, and nD States of Atomic Hydrogen Abstract The excitation cross sections of the atomic hydrogen from n=2 ton=6 have been calculated for S, P, and D, from low energies to high incident energies (threshold to 100 eV), using the variational polarized orbital method (hybrid theory). Thirty partial waves been used to obtained converged cross sections. The maximum of elastic and excitation cross sections is at incident energy 26.66 eV. Introduction The well-known relativistic wave equation was formulated in 1928 by Dirac [1]. He combined the ideas of relativity and quantum mechanics to formulate the equation and predicted an antiparticle of spin ħ/2. He assumed that the antiparticle must be a proton because at that time only two particles namely proton and electron were known. However, Hermann Weyl, from symmetry consideration, suggested that the positive particle must have the same mass as that of an electron. Later on, this p...