PEOPLE


Dr. Alexandu Popa

email: alexandu.popa_at_inflpr.ro

Alexandru Popa received the Physicist Engineer degree from the Polytechnic University of Bucharest, Romania in 1966, the M. Sc degree from the University of California, Berkeley in 1972 and the Ph. D. degree from the Polytechnic University of Bucharest, Romania in 1974. He is currently a Senior Researcher at the Laser Department, National Institute for Laser, Plasma and Radiation Physics, Bucharest.

Until 1975 he worked on electronic device modeling, his results being published in IEEE Transactions on Electron Devices. During 1975-1989 he worked in the field of scanning electron microscopy and X ray spectrometry, with application to the study and the characterization of the materials. A constant research interest was modeling optimization at the atomic and molecular scale.

In the last period he worked in the following research fields:

  1. In the field of connections between quantum and classical equations with applications to the modeling of stationary states he has the following achievements:

    1) A wave model for stationary atomic and molecular systems [1]-[5].

    2) A semiclassical central field method for the calculation of energetic values for stationary systems, on the basis of the previous wave model. His approach is in good agreement with experimental values, for numerous atoms and diatomic molecules. The accuracy of his method is comparable with the accuracy of the Hartree-Fock method [6]-[8].

  2. In the field of interactions between medium and very intense laser beams and electrons, atoms and material surfaces he has the following achievements:

    1) A model for metallic surfaces emitting second harmonic generator [9].

    2) A nonlinear model of interaction between electromagnetic waves and polar semiconductors [10].

    3) Proofs of an accurate connection between quantum and classical equations in interactions between very intense laser fields and electrons or atoms [11], [12].

    4) A model of hard X radiations generation by relativistic Thomson scattering [13], [14] and a periodicity property of relativistic Thomson scattering, with application to exact calculation of angular and spectral distributions of scattered field [15].

    5) A model for the study of the polarization effects in collisions between very intense laser beams and relativistic electrons [16].

    6) A model for the calculation of the harmonic spectrum generated at the interaction between very intense laser fields and atoms [17].

    7) A model for the calculation of the angular and spectral distributions of the radiations generated at the interaction between very intense laser beams and electron plasmas [18].

    8) A calculation method for the radiation damping parameters in the interaction between very intense laser beams and relativistic electron beams [19].

    A synthesis of his results is published in two books [20], [21].




SELECTED PAPERS

  1. A. Popa, "Applications of a Property of the Schrödinger Equation to the Modeling of Conservative Discrete Systems," Journal of the Physical Society of Japan, Vol. 67, No. 8, 1998, p. 2645-2652.

  2. A. Popa, "Applications of a Property of the Schrödinger Equation to the Modeling of Conservative Discrete Systems. II," Journal of the Physical Society of Japan, Vol. 68, No. 3, 1999, p. 763-770.

  3. A. Popa, "Applications of a Property of the Schrödinger Equation to the Modeling of Conservative Discrete Systems. III," Journal of the Physical Society of Japan, Vol. 68, No. 9, 1999, p. 2923-2933.

  4. A. Popa, “Connection between the periodic solutions of the Hamilton-Jacobi equation and the wave properties of the conservative bound systems”, Journal of Physics A: Mathematical and General, Vol. 36. pp. 7569-7578, 2003.

  5. A. Popa, “Wave model for conservative bound systems”, Journal of Chemical Physics, Vol. 122, pp 244701(1-6), 2005.

  6. A. Popa, Semiclassical method for calculating the energetic values of helium, lithium and beryllium atoms, “ European Physical Journal D, Vol. 49, pp. 279-292, 2008.

  7. A. Popa, Geometrical symmetry of atoms with applications to semiclassical calculation of energetic values, “ European Physical Journal D, Vol. 54, pp. 575–583, 2009.

  8. A. Popa, Unconventional semiclassical method for calculating the energetic values of diatomic molecules,Molecular Physics, Vol. 109, pp. 575–588, 2011.

  9. A. Popa, M. Lazarescu, R. Dabu, A. Stratan, "A Model of the Metallic Surface-Emitting Second Harmonic Generator," IEEE Journal of Quantum Electronics, Vol. 33, No. 9, 1997, p. 1474-1480.

  10. A. Popa, “Nonconventional calculation of the second order susceptibility in polar semiconductors”, Journal of Physics: Condensed Matter, Vol. 15, pp. L559-L564, 2003.

  11. A. Popa, A New Approach on Studying Electron Behavior Under Very Intense Laser Beam”, IEEE Journal of Quantum Electronics, Vol. 40, pp. 1519-1523, 2004.

  12. A. Popa, “From Quantum to Classical Effects in Interactions Between Electrons and Very Intense Laser Beams,” IEEE Journal of Quantum Electronics, Vol. 43, pp. 1183-1187, 2007.

  13. A. Popa, “Accurate calculation of high harmonics generated by relativistic Thomson scattering, “ Journal of Physics B : Atomic, Molecular and Optical Physics, Vol. 41, 015601, 2008.

  14. A. Popa, “Modelling properties of hard x-rays generated by the interaction between relativistic electrons and very intense laser beams,“ Journal of Physics B : Atomic, Molecular and Optical Physics, Vol. 42, 025601, 2009.

  15. A. Popa, Periodicity property of relativistic Thomson scattering, with application to exact calculation of angular and spectral distributions of scattered field,” Physical Review A, Vol. 84, 023824, 2011

  16. A. Popa, Polarization effects in collisions between very intense laser beams and relativistic electrons,” Laser and Particle Beams, Vol. 30, pp. 591-603, 2012.

  17. A. Popa, Dependence of Harmonic Spectrum Shape on Laser Beam Intensity in Interaction with Atoms,” IEEE Journal of Quantum Electronics,ol. 49, pp. 522-527, 2013.

  18. A. Popa, Accurate Calculation of High Harmonics Generated by Interactions between Very Intense Laser Fields and Electron Plasmas,” IEEE Transactions on Plasma Science, Vol. 41, pp. 2246-2250, 2013.

  19. A. Popa, Accurate calculation of radiation damping parameters in the interaction between very intense laser beams and relativistic electron beams, Laser and Particle Beams, Vol. 32, pp. 477-486, 2014.

    BOOKS

  20. A. Popa, Theory of Quantum and Classical Connections in Modeling Atomic, Molecular and Electrodynamic Systems, Elsevier-Academic Press, Amsterdam, Boston, 2013.

  21. A. Popa, Applications of Quantum and Classical Connections in Modeling Atomic, Molecular and Electrodynamic Systems, Elsevier-Academic Press, Amsterdam, Boston, 2013.