Simultaneous electron-photon excitation of atomic targets

International Conference on Quantum Physics and Nuclear Engineering

March 14-16, 2016 London, UK

Saxena Sanjeev

Bareilly College, India

Posters & Accepted Abstracts: J Laser Opt Photonics

Abstract :

Atomic collision processes control the composition of upper and lower atmosphere. Such studies are helpful to understand the facts behind the ozone layer depletion by simple series of atomic collisions. An accurate knowledge of the rates for electron excitation of atoms in presence of electromagnetic field is used in modeling of stellar plasmas, fusion plasmas and laser induced plasmas. Electron-atom scattering in the presence of a laser field is a rapidly and fast growing subject. This study is very useful from the point of view of plasma heating, population of metastable states and gas break down phenomenon. The electron atom scattering in the presence of a resonant laser field was investigated by so many theoreticians. Some of them have derived a time dependent close coupling approach for particle scattering by a two state atom, generated by the strong near resonant field. The process of joint atomic excitation is quite different from the normal electron atom excitation process in that the total cross section here shows resonant structures when the laser frequency is varied. At near resonant frequencies the cross sections are substantially larger compared to the field free cross sections. In present paper, I would propose two phases. The first phase is devoted to the study of electron. That is Hydrogen atom scattering in presence of electromagnetic field. The variation of the cross section with laser intensity and with incident electron energy is too investigated for the optically forbidden s-s and s-d type transitions. The effect of laser on the individual magnetic sub-state excitation when the final state is a �d� state, is also observed. The variation of differential cross sections with the scattering angle at incident electron energy is also presented at different laser intensities. In the second phase of proposed paper, the above study would be extended to Helium atom. The use of pseudo-states as intermediate states is also being taken into account. Here, I would assume that laser is non-resonant with any atomic level. I predicted major changes in the joint excitation cross section of Helium atom due to a multi-pole interference effect, near the resonant frequencies corresponding to the quadrupole allowed intermediate states. As far as my knowledge, such effects have not been studied so far. The present calculation is done by taking the asymptotic wave functions hence extracted the phase shift accordingly. The detailed results shall be presented as well discussed at the venue of conference.

Biography :

Email: sanjiv.sxn@gmail.com