Accession Number : ADA640859


Title :   Relativistic Photoionization Computations with the Time Dependent Dirac Equation


Descriptive Note : Interim rept. Apr 2016-Aug 2016


Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC BEAM PHYSICS BRANCH


Personal Author(s) : Gordon, Daniel F ; Hafizi, Bahman


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a640859.pdf


Report Date : 12 Oct 2016


Pagination or Media Count : 25


Abstract : Ionization of inner shell electrons by laser fields often occurs in the relativistic regime. A complete description of this phenomenon requires both relativistic and quantum mechanical treatment. The Dirac equation describes the motion of a spin one-half particle in an external electromagnetic field. The stationary states in both Coulomb and soft-core potentials are solved either analytically or numerically. These are used as initial conditions in time dependent calculations. It is found that, at least in one case, two-dimensional simulations predict a greater ionization rate than the one predicted by the Coulomb corrected strong field approximation. Computational performance is important due to the rapid oscillations in a relativistic wavefunction. Multiple General Purpose Graphical Processing Units are utilized in parallel to speed up calculations.


Descriptors :   *HIGH PERFORMANCE COMPUTING , *PHOTOIONIZATION , QUANTUM ELECTRONICS , RELATIVISTIC ELECTRONS , SPECIAL FUNCTIONS(MATHEMATICS) , TUNNELING(ELECTRONICS) , WAVE FUNCTIONS


Subject Categories : Electrical and Electronic Equipment
      Numerical Mathematics
      Computer Hardware
      Quantum Theory and Relativity


Distribution Statement : APPROVED FOR PUBLIC RELEASE