Enhanced electron acceleration via ultra-intense laser interaction with structured targets
Autori: Fedeli L., Sgattoni A., Cantono G., Prencipe I., Passoni M., Klimo O., Proska J., Macchi A., Ceccotti T.
Affiliazione autori: Univ Pisa, Dept Phys Enr Fermi, I-56127 Pisa, Italy; CNR, Ist Nazl Ott, Uos Adriano Gozzini, I-56124 Pisa, Italy; CEA, DSM, IRAMIS, LIDYL, F-91191 Gif Sur Yvette, France; Univ Paris Sud, Paris, France; Politecn Milan, Dipartimento Energia, I-20133 Milan, Italy; Czech Tech Univ, Prague 16636 6, Czech Republic
Abstract: The generation of energetic electrons by the interaction of a short laser pulse with solid “grating” targets, having a periodic groove on the irradiated surface, has been investigated in a regime of ultrahigh contrast (10(12)) and relativistically strong intensity (> 10(19)W/cm(2)). A strong enhancement of both the energy and number of electrons emitted from the target, with respect to flat targets, has been observed for incidence angles close to the resonant condition for surface wave excitation. In particular we identified bunches of electrons with energies exceeding 10 MeV which are emitted in a direction close to the target surface. The experimental results are well reproduced by a three-dimensional particle-in-cell simulation, which confirms the dominant role of the surface wave in accelerating the electrons. These results are a step forward the development of high field plasmonics for a number of applications.
Parole chiavi: laser; plasma; grating; electron acceleration; plasmonics