Title :
Effects of front surface plasma expansion on proton acceleration in ultraintense laser irradiation of foil targets
Author :
McKenna, P. ; Carroll, D.C. ; Lundh, O. ; Nürnberg, F. ; Markey, K. ; Bandyopadhyay, S. ; Batani, D. ; Evans, R.G. ; Jafer, R. ; Kar, S. ; Neely, D. ; Pepler, D. ; Quinn, M.N. ; Redaelli, R. ; Roth, M. ; Wahlström, C.G. ; Yuan, X.H. ; Zepf, M.
Author_Institution :
Dept. of Phys., Univ. of Strathclyde, Glasgow, UK
Abstract :
The properties of beams of high energy protons accelerated during ultraintense, picosecond laser-irradiation of thin foil targets are investigated as a function of preplasma expansion at the target front surface. Significant enhancement in the maximum proton energy and laser-to-proton energy conversion efficiency is observed at optimum preplasma density gradients, due to self-focusing of the incident laser pulse. For very long preplasma expansion, the propagating laser pulse is observed to filament, resulting in highly uniform proton beams, but with reduced flux and maximum energy.
Keywords :
foils; high-speed optical techniques; optical self-focusing; plasma accelerators; plasma density; plasma light propagation; plasma production by laser; proton accelerators; front surface; high energy protons; incident laser pulse self-focusing; laser-to-proton energy conversion efficiency; picosecond laser irradiation; plasma expansion; preplasma density gradients; proton acceleration; thin foil targets; ultraintense laser irradiation; Acceleration; Energy conversion; Laser beams; Optical propagation; Optical pulses; Particle beams; Plasma accelerators; Plasma properties; Protons; Surface emitting lasers; Laser-plasma interaction; laser-proton acceleration; plasma expansion;
Conference_Titel :
Plasma Science - Abstracts, 2009. ICOPS 2009. IEEE International Conference on
Conference_Location :
San Diego, CA
Print_ISBN :
978-1-4244-2617-1
DOI :
10.1109/PLASMA.2009.5227320
