The transverse filamentation of beams of fast electrons transported in solid targets irradiated by ultraintense (5 × 1020 Wcm^−2), picosecond laser pulses is investigated experimentally. Filamentation is diagnosed by measuring the uniformity of a beam of multi-MeV protons accelerated by the sheath field formed by the arrival of the fast electrons at the rear of the target, and is investigated for metallic and insulator targets ranging in thickness from 50 to 1200μm. By developing an analytical model, the effects of lateral expansion of electron beam filaments in the sheath during the proton acceleration process is shown to account for measured increases in proton beam nonuniformity with target thickness for the insulating targets.
On the investigation of fast electron beam filamentation in laser-irradiated solid targets using multi-MeV proton emission / M. n., Quinn; D. c., Carroll; X. h., Yuan; M., Borghesi; R. j., Clarke; R. g., Evans; J., Fuchs; P., Gallegos; Lancia, Livia; K., Quinn; A. p. l., Robinson; L., Romagnani; G., Sarri; C., Spindloe; P. a., Wilson; D., Neely; P., Mckenna. - In: PLASMA PHYSICS AND CONTROLLED FUSION. - ISSN 0741-3335. - 53:12(2011), p. 124012. [10.1088/0741-3335/53/12/124012]
On the investigation of fast electron beam filamentation in laser-irradiated solid targets using multi-MeV proton emission
LANCIA, LIVIA;
2011
Abstract
The transverse filamentation of beams of fast electrons transported in solid targets irradiated by ultraintense (5 × 1020 Wcm^−2), picosecond laser pulses is investigated experimentally. Filamentation is diagnosed by measuring the uniformity of a beam of multi-MeV protons accelerated by the sheath field formed by the arrival of the fast electrons at the rear of the target, and is investigated for metallic and insulator targets ranging in thickness from 50 to 1200μm. By developing an analytical model, the effects of lateral expansion of electron beam filaments in the sheath during the proton acceleration process is shown to account for measured increases in proton beam nonuniformity with target thickness for the insulating targets.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
