Sobre o evento

O Clube de Estudantes Women in Physics está muito feliz por anunciar a Prof. Caterina Riconda como oradora para o nosso primeiro evento WiP Seminars.

Nos WiP Seminars tens a oportunidade não só de aprender sobre a investigação feita por físicas de renome internacional, mas também de participar numa conversa informal com elas e perguntar sobre a sua carreira. Não te esqueças de te inscrever!

A nossa primeira oradora é uma física de plasmas com especial interesse nas interacções entre plasma e tanto lasers como campos ultra intensos. Caterina Riconda é professora na Universidade Sorbonne em Paris e lidera o grupo “Teoria e Interpretação, Plasmas e Simulações” (TIPS) no Laboratoire d’Utilisation des Lasers Intenses (LULI).

Sobre a oradora

Caterina Riconda recebeu o seu Mestrado na Universidade de Turim, Itália, e o seu doutoramento em Física do Massachusetts Institute of Technology, EUA, em 1996. Após cargos no Joint European Torus, Reino Unido, na École Polytechnique, CEA Saclay, e na Universidade de Bordeaux em França, é agora professora catedrática na Universidade Sorbonne, em Paris. Os seus interesses de investigação incluem física dos plasmas, teoria cinética dos plasmas, interacções laser-plasma, e interacções entre campos ultra intensos e plasma. É líder do grupo Teoria e Interpretação, Plasmas e Simulações (TIPS) no Laboratoire d’Utilisation des Lasers Intenses (LULI).

Abstract do seminário

(apenas disponível em inglês)

The availability for the scientific community of compact sources of intense, high-power, ultrashort laser pulses, allowed a rapid growth of studies on laser driven electron accelerators. Different laser plasma acceleration mechanisms have been explored. A by now well know scheme involves the generation of huge acceleration gradients, up to 10 to 100 GV/m, due to the propagation of a TW-class laser pulse in a diluted plasma. GeV scale and very short duration (some fs) electron beams produced in this way are a natural candidate as drivers for a free-electron laser or to be coupled into undulators to produce radiation in the visible and X-ray domain.

After a brief review of these mechanisms, we present an alternative approach: the generation of fast electron beams in relativistic laser-solid interaction. The studies in this domain are mainly stimulated by the possibility of having higher electron currents due to the high density. In laser-solid interaction the energy coupling between the laser beam and the target is mainly localized at the surface and the coupling efficiency needs to be optimized in order to get an energetic electron distribution. One way is to use properly-structured targets whose surface characteristics match with the laser parameters, so that surface plasma waves are excited¹. As will be discussed, the surface plasma wave (plasmons) excitation on solid grating target enhances drastically the laser absorption in ultra-high intensity interaction regime ($ I\lambda^2>10^{18} ~ \mathrm{W cm^{-2} \mu m^2} $) and generates large currents of relativistic electrons. Theoretical, numerical (via the Particle-in-Cell method) and experimental studies of fast electron generation will be presented.

Recently, a simple scaling for the conversion of surface wave field energy into electrons kinetic energy has been identified by our group by considering the interaction of test electrons with the evanescent high frequency field of a surface wave². We were able to show that the most energetic relativistic electrons are accelerated parallel to the plasma-vacuum interface to velocities larger than the wave phase velocity. These results have been confirmed by Particle-in-Cell simulation and experiments³. A new scheme was proposed recently, combining a smart grating design with high intensity laser pulses with wavefront rotation, allowing to tune the duration and intensity of the surface plasma waves, capable of accelerating ultrashort and energetic electron bunches⁴.