Study For Electron-Atom Ionization Of Helium Atom In Presence Of Circular Polarization Laser Field

Study for triple differential cross sections in the presence of the laser filed.The target atom is the state helium atom.When the incident electron energy is high,we can treat electron-atom collisions as three-body problem.Three-body problem can't be solved because of laser filed and the residual impact the ejected electron.we should solve the problem under the help of other approximation methods.we use Born approximation treatments in the article.We use Volkov or Coulomb-Volkov waves to describe the state of incident electron,scattering electron and ejected electron in the presence of the laser filed.The initial state is described by incident electron and target atom product.The final state is described by scattering electron and ejected electron product.When considering the Stark effect,we should calculate the dressing terms of the target atom though the perturbation theory.We calculate scattering matrix elements transition matrix elements and the triple differential cross sections under the condition of first Born treatment.Under the help of Mathematica,we can obtain the picture of the triple differential cross sections.When scattering angle and effective charge number is increasing,the binary peak is suppressed.when the ejected energy is increasing,the binary peak is promoted in the presence of the laser filed.The result is in keeping with filed-free.The picture is different between Filed-free and unconsidering the Stark effect in the presence of the laser filed,we found that the laser filed can improve the binary peak.when the intensity of the laser filed improve,the binary peak is improved at the same time.Comparing with considering the Stark effect and unconsidering the Stark effect,we found that the new phenomenon is appearing,the binary peak is divided two binary peaks.