Home

CURRICULUM VITAE

Family name : BUICA (formerly ZLOH)

First name: GABRIELA

Date and place of birth: July 17, 1968, Craiova, ROMANIA

Nationality: Romanian

Studies:

PhD. in Atomic Physics, University of Craiova (1999), Faculty of Physics, the jury: M. Preda, O. Gherman (supervisor), V. Florescu, A. Cionga, and T. Marian,

B.Sc. Faculty of Physics, University of Craiova (1986-1991),

High School of Philology-History, Craiova (1982-1986),

Elementary school, Craiova (1974-1982).

Positions held:

Postdoctoral Position JSPS (Japan Society for the Promotion of Science, May 2005-June 2006) at Institute of Advanced Energy, Kyoto University, Japan,

Scientific Researcher (since July 2003-present) at Institute of Space Sciences, National Institute for Laser, Plasma, and Radiation Physics, Bucharest, Romania,

Postdoctoral Position (European Research Network Programs FP5, July 2001-June 2003) at Institute of Electronic Structure and Laser, FORTH, Greece,

Scientific Researcher (1998- June 2001) at Institute of Space Sciences, National Institute for Laser, Plasma, and Radiation Physics, Bucharest, Romania,

Assistant Researcher (1995-1998) at Institute of Space Sciences, National Institute for Laser, Plasma, and Radiation Physics, Bucharest, Romania,

High School Teacher (1991-1995) at Mihai Viteazul High School, Bailesti, Romania.

Permanent Address:

Institute of Space Sciences, Atomistilor No. 409, P.O. BOX MG-23, Bucharest-Magurele, R-77125, Bucharest, Romania, Tel&fax: +(40-21) 4574471, e-mail: buica@spacescience.ro, gzloh@yahoo.com.

Foreign Languages: English, French

Computer Skills: WINDOWS, LINUX, FORTRAN, HTML, WORD, LATEX, ORIGIN, MATHEMATICA, MAPLE

Founded Projects:

Main research domains and achievements

Scientific reSults

I) Elastic electron-atom scattering in an electromagnetic field (free-free transitions) (in coll. with A. Cionga and F. Ehlotzky)

a) In the low intensity domain of the electromagnetic field

• I have studied free-free transitions in laser-assisted electron-Hydrogen scattering in a bichromatic electromagnetic field. I have derived within the time-dependent perturbation theory an analytical formula for the elastic differential cross sections (DCS) for free-free transitions involving two different photons.

• The dependence of the DCS on the scattering angle and photon energy was investigated. Extensive calculation were performed in the domain of small scattering angles, where the dressing of the target is important.

• In the case of circularly and elliptically polarized field I have studied the dependence of DCS's on the helicity of photons. For a superposition of a linearly and a circularly polarized lasers we shown that circular dichroism in the angular distribution can be predicted for the nonlinear two-photon transitions, if the dressing of the atomic target by the laser field is treated in second order of perturbation theory. Of special interest is that for particular configurations circular dichroism can be encountered not only in the differential but also in the integrated cross sections.

b) In the moderate intensity domain of the electromagnetic field

• I have studied free-free transitions in laser-assisted electron-Hydrogen scattering in a bichromatic field of frequencies w and 2w. A semiperturbative approach is used, in which the projectile-field interaction is described exactly but the field-target one is described by second order perturbation theory.

• I have studied the dependence of DCS's on the projectile energy, scattering geometry, photon energy, polarization of the field

• I have investigated in detail the DCS in the domain of small scattering angles, where the dressing of the target is important. The effect of the intensities of the two components of the bichromatic field and that of their relative phase is investigated, too. Special attention was paid to the study of free-free transitions involving photon energies connected to atomic resonances.

c) Elastic electron scattering by excited atoms in an electromagnetic field

• I have investigated the scattering of fast electrons by excited Hydrogen atoms (in particular, in the 2s, 2p or ns states) in the presence of a linearly polarized laser field of moderate power such that target-dressing can be treated within first-order time dependent perturbation theory.

• I analyzed the angular dependence of the nonlinear DCS's, inspecting the contributions of the various electronic and atomic terms of the matrix elements. Detailed numerical results are presented for one-photon absorption revealed that the scattering process is greatly influenced by the dressing of the target in particular at small scattering angles.

The obtained results were published in ISI scientific journals and presented at international conferences.

II) Multiphoton ionization of a two-valence-electron atom (in coll. with P. Lambropoulos, L. Nikoloupoulos and T. Nakajima)

• I have studied the multiphoton ionization of a two-valence electron atom in a strong ultrashort laser field employing a nonperturbative method in order to solve the time-dependent Schrodinger equation. In this context I have investigated the total and partial ionization yields, and the above-threshold ionization spectra (ATI) of Mg in a Ti:Sapphire laser field when multiple ionization thresholds are involved in the ionization process.

• I have studied two-, three- and four-photon ionization of Mg in its ground state 3s^{2 1}S and 3s3p ³P by an ultrashort laser pulse. We have calculated the two-, three-, and four-photon ionization cross section by a linearly and circularly polarized laser field. A frozen core Hartree-Fock method and a model potential were used in order to describe the interaction between the ionic core and the valence electrons. The dependence of the photolectron energy spectrum on the temporal profile of the pulse was investigated. Since the Mg atom has a dense electronic structure the photolectron energy spectrum exhibits interesting features such as intermediate ATI peaks; our studies showed that the origin of those intermediated ATI peaks is connected to ionization from the 3snp ¹P (n=3,4,5,... etc) bound excited states.

• I have studied two-photon ionization of Ca in its ground state 4s^{2 1}S by an ultrashort linearly and circularly polarized laser field. The dependence of the photolectron energy spectrum on the temporal profile of the pulse was investigated. Furthermore the photolectron angular distributions were calculated. Since the Ca atom has a dense electronic structure the photolectron energy spectrum exhibits interesting features such as intermediate ATI peaks; our studies showed that the origin of those intermediated ATI peaks is connected to ionization from the 4snp ¹P(n=4,5,6... etc) bound excited states.

III) Control of physical processes in electromagnetic fields (in coll. with A. Cionga, F. Ehlotzky, P. Lambropoulos, L. Nikoloupoulos and T. Nakajima)

a) Coherent control for the electron-H atom scattering in an electromagnetic field

I have investigated coherent phase control in electron scattering by Hydrogen atoms in a bichromatic laser field of frequencies w and 2w. The effect of the relative phase between the components of the bichromatic laser field on the scattering process was studied.

b) Coherent control for autoionizing states of Mg

I have studied the coherent phase control of the autoionizing state 3p² of Mg in a bichromatic laser field of frequencies w and 2w. A motivation for this study was the investigation of the possibility of achieving coherent control of the photoelectron current and the shape of the autoionizing resonance. I have carried out calculation for the multiphoton ionization rate with the laser frequencies chosen such that the ground state of Mg atom is resonantly coupled to the 3s3p and 3s4p levels. The model has taken into account a realistic atomic structure and transition amplitudes calculation.

c) Control of laser induced continuum structure of K

I have examined how the photoelectron angular distribution (PAD) is altered through laser induced continuum structure (LICS) by the introduction of a dressing laser. We theoretically investigated the effects of LICS on PAD for a specific atomic system: the K atom 4p_1/2-6p_1/2, and 4p_3/2-6p_3/2 levels. It turned out that the PAD's are quite different for both systems, and the alteration of PAD by the laser parameters is important, as we expected, and LICS could be used to control the ionization processes.

The obtained results were published in ISI scientific journals and presented at international conferences.

Scientific works:

Published in scientific journals:

Multiphoton ionization of the Calcium atom by linearly and circularly polarized laser fields, (in coll. with T. Nakajima), Phys. Rev. A, 81, 043418 (2010) paper.pdf

Multiphoton ionization through the triplet states of Mg by linearly and circularly polarized laser pulses, (in coll. with T. Nakajima), Phys. Rev. A, 79, 013419 (2009) paper.pdf

Two-, three-, and four-photon ionization of Mg in the circularly and linearly polarized laser fields: Comparative study using the Hartree-Fock and model potentials, (in coll. with T. Nakajima), Journal of Quantitative Spectroscopy and Radiative Transfer, 109 (1), 107 (2008), paper.pdf

Above-threshold ionization of Mg by linearly and circularly polarized laser fields: Origin of the sub-peaks in the photoelectron energy spectra, (in coll. with T. Nakajima), Phys. Rev. A, 74, 023411 (2006), paper.pdf

Effects of laser polarization on photoelectron angular distribution through laser-induced continuum structure, (in coll. with T. Nakajima), Phys. Rev. A, 72, 053416 (2005), paper.pdf

Modification of photoelectron angular distribution through laser induced continuum structure, in coll. with T. Nakajima), Phys. Rev. A, 71, 013413 (2005) paper.pdf,

Coherent phase control in autoionization of Magnesium by a bichromatic laser field of frequencies w and 2w (in coll. with L.A.A. Nikolopoulos), Eur. Phys. J. D 29, 201 (2004), paper.pdf

Multiphoton Ionization of Magnesium in a Ti-Sapphire laser field (in coll. with L.A.A. Nikolopoulos and P. Lambropoulos), Eur. Phys. J. D 26, 245 (2003) paper.pdf,

Elastic electron scattering by excited hydrogen atoms in a laser field (in coll. with A. Cionga and F. Ehlotzky), Phys. Rev. A 64, 043401 (2001) paper.pdf,

Coherent phase control in electron scattering by hydrogen atoms in a bichromatic laser field (in coll. with A. Cionga and F. Ehlotzky), Journal of Phys. B 34, 2057 (2001) paper.pdf,

Dichroism in high energy electron-hydrogen scattering in an elliptically polarized laser field (in coll. with A. Cionga and F. Ehlotzky), Optics Communication (192) 3-6, 255-262 (2001) paper.pdf,

Circular dichroism in differential and integrated cross sections of free-free transitions in high energy electron-atom scattering, (in coll. with A. Cionga and F. Ehlotzky), Journal of Phys. B, 33, 4939 (2000) paper.pdf,

Circular dichroism in free-free transitions of high energy electron-atom scattering, (in coll. with A. Cionga and F. Ehlotzky), Phys. Rev. A, 62, 063406 (2000) paper.pdf,

Electron-atom scattering in a circularly polarized laser field (in coll. with A. Cionga and F. Ehlotzky), Phys. Rev. A, 61, 063417 (2000) paper.pdf,

Phase Effects in Two-Photon Free-Free Transitions in a Bichromatic Field of Frequencies w and 3w (in coll. with A. Cionga), Laser and Particles Beams, 18, 549 (2000) paper.pdf,

Free-Free Transitions in a Bichromatic Field of Frequencies w and 2w at Moderate Field Intensities (in coll. with A. Cionga), Laser Phys. 9, 69 (1999),

Polarization Effects in Two-Photon Free-Free Transitions in Laser-Assisted Electron-Hydrogen Collisions (in coll. with A. Cionga), Laser Phys. 8, 164 (1998),

Two-color Free-Free Transitions in Laser-Assisted Electron-Hydrogen Scattering (in coll. with A. Cionga), Balkan Phys. Lett. 5, 258 (1997).

Published in volumes:

The interaction of electromagnetic field with matter, B.Sc. diploma, University of Craiova, Faculty of Physics, June 1991,

Contributions to the Study of Free-Free Transitions in a Bichromatic Electromagnetic Field, PhD. thesis, University of Craiova, Faculty of Physics, June 1999,

Target Dressing Effects in Laser-Assisted Electron-Hydrogen Scattering (in col. cu A. Cionga), Proc. 19^th SPIG'98, Zlatibor, Yugoslavia 1998, Contributed Papers, Eds. N.Konjevic, M.Cuk, I.R.Videnovic, (University of Belgrade, Faculty of Physics, Belgrade), 1998, pag. .47-50, I = 0.1.

Elliptic Dichroism in Angular Distributions in Free-Free Transitions in Hydrogen (in col. cu A. Cionga si F. Ehlotzky), pag. 351-356 in Atoms, Solids and Plasmas in Super-intense Laser Fields, Proceedings of the 30th Course of the International School of Quantum Electronics on Atoms, Solids and Plasmas in Super-Intense Laser Fields, 8-14 July, Erice, Sicily, Ed.s. Batani, D.; Joachain, C.J.; Martellucci, S.; Chester, A.N. 2001, ISBN: 978-0-306-46615-1, pag. 351-356, I = 0.1 .

Contributions at international conferences:

XX International Conference on the Physics of Electronic and Atomic Collisions, Vienna, July 1997, Target Dressing Effects in Free-Free Transitions in Hydrogen: Two-Color Two-Photon Processes (in coll. with A. Cionga),

BPU-3, 3rd General Physics Conference of the Balkan Physics Union, 2-5 September, 1997, Babes-Bolyai University, Cluj-Napoca, Romania, Two-color Free-Free Transitions in Laser-Assisted Electron-Hydrogen Scattering (in col. cu A. Cionga),

Research Workshop of the Israel Science Foundation on Photo-Induced Nonlinear Dynamics in Strong Laser Fields, Haifa, Feb. 1998, Phase-Effects in (n+1)-Color Two-Photon Free-Free Transitions in Laser Assisted Electron-Hydrogen Scattering (in coll. with A. Cionga),

16^th International Conference on Atomic Physics ICAP XVI, Windsor, Aug. 1998, Electron-Hydrogen Scattering in a Trichromatic Laser Field: Phase Effects (in coll. with A. Cionga), p. 417,

The 7^th International Workshop on Laser Physics, Berlin, July 1998, Target Dressing Effects in Electron-Hydrogen Scattering in Bichromatic Fields (in coll. with A. Cionga),

Ultraintense Laser Interactions and Applications-1, Elounda, Greece, May 1999, Electron-Hydrogen Collisions in a Bichromatic Field at Moderate Intensities (in coll. with A. Cionga),

The 8^th International Workshop on Laser Physics, Budapest, July 1999, Free-free Transitions in Electron-Hydrogen: Second Order Field-Induced Corrections to the Elastic Line (in coll. with A. Cionga),

The 8^th International Conference of Multiphoton Processes, Monterey, USA, Oct. 1999, Circular Dichroism in Free-Free Transitions at High Scattering Energies (in coll. with A. Cionga and F. Ehlotzky),

International Workshop and Seminars on Atomic Systems in Extreme Fields, Dresden, March 2000, Circular Dichroism in electron-Hydrogen Scattering in a Bichromatic Field (in coll. with Aurelia Cionga and F. Ehlotzky),

Atoms, Molecules and Quantum Dots in Laser Fields: Fundamental Processes, Pisa, Italy, June 2000, Elliptical Dichroism in Angular Distribution for Laser-Assisted Electron-Hydrogen Scattering (in coll. with Aurelia Cionga and F. Ehlotzky),

International School of Quantum Electronics: 30th Course: ATOMS,SOLIDS AND PLASMAS IN SUPER-INTENSE LASER FIELDS, Ettore Majorana Centre, Erice, Italy, July 2000, Dichroic Effects in Free-Free Transitions (in coll. with Aurelia Cionga and F. Ehlotzky),

NATO Advanced Research Workshop: SUPER-INTENSE LASER-ATOM PHYSICS-SILAP 2000-Han-sur-Lesse, Belgium, Sept 2000, Elastic electron scattering by an excited atom in a laser field (in coll. with Aurelia Cionga and F. Ehlotzky),

International Conference on Multiphoton Processes (ICOMP) IX, Elounda, Greece, October 2002, Multiphoton Ionization of Magnesium in a Ti-Sapphire laser field (in coll. with L.A.A. Nikolopoulos and P. Lambropoulos),

International Conference on Multiphoton Processes (ICOMP) IX, Elounda, Greece, October 2002, Coherent phase control in autoionization of Magnesium by a bichromatic laser field of frequencies w and 2w (in coll. with L.A.A. Nikolopoulos and P. Lambropoulos),

International School of Quantum Electronics: 37th Course: ATOMS,SOLIDS AND PLASMAS IN SUPER-INTENSE LASER FIELDS, Ettore Majorana Centre, Erice, Italy, July 2003, Coherent phase control in autoionization of Magnesium by a bichromatic laser field of frequencies w and 2w (in coll. with L.A.A. Nikolopoulos),

International Workshop and Seminar: RYDBERG PHYSICS, Max-Planck-Institut für Physik Komplexer Systeme Dresden, Germany, April 19 - May 14, 2004, Rydberg states of Magnesium in laser field,

IAMPI2006 International Conference on the Interaction of Atoms, Molecules and Plasmas with Intense Ultrashort Laser Pulses, Szeged, Hungary, 1-5 October, 2006 : Origin of the side peaks appearing in the above-threshold ionization spectra of Mg (in coll. with T. Nakajima).

ICPEAC XXV International Conference on the Physics of Electronic and Atomic Collisions, Freiburg, Germany, 24-31.07.2007 Spin-orbit effects in electron-hydrogen-like ion elastic scattering in a laser field (in coll. with T. Nakajima).

CEPAS 2008, 4^th Conference on Elementary Processes in Atomic Systems, Cluj- Napoca, Romania, 17-21.06.2008, “Above-threshold ionization of calcium by linearly and circularly polarized laser pulses”.

Advanced Workshop: Spin and Charge Properties of Low Dimensional Systems, IFIN-HH and ICTP-Trieste, Sibiu, Romania, June 2009, “Multiphoton ionization of calcium by linearly and circularly polarized laser pulses”.