Burza, M. and Gonoskov, A. and Genoud, G. and Persson, A. and Svensson, K. and Quinn, M. and McKenna, P. and Marklund, M. and Wahlstrom, C-G (2011) Hollow microspheres as targets for staged laser-driven proton acceleration. New Journal of Physics, 13 (Januar). 013030. ISSN 1367-2630Full text not available in this repository. (Request a copy from the Strathclyde author)
A coated hollow core microsphere is introduced as a novel target in ultra-intense laser-matter interaction experiments. In particular, it facilitates staged laser-driven proton acceleration by combining conventional target normal sheath acceleration (TNSA), power recycling of hot laterally spreading electrons and staging in a very simple and cheap target geometry. During TNSA of protons from one area of the sphere surface, laterally spreading hot electrons form a charge wave. Due to the spherical geometry, this wave refocuses on the opposite side of the sphere, where an opening has been laser micromachined. This leads to a strong transient charge separation field being set up there, which can post-accelerate those TNSA protons passing through the hole at the right time. Experimentally, the feasibility of using such targets is demonstrated. A redistribution is encountered in the experimental proton energy spectra, as predicted by particle-in-cell simulations and attributed to transient fields set up by oscillating currents on the sphere surface.
|Keywords:||thin foils, intensity, generation, contrast, pulses, beams, ions, Physics, Physics and Astronomy(all)|
|Subjects:||Science > Physics|
|Department:||Faculty of Science > Physics|
|Depositing user:||Pure Administrator|
|Date Deposited:||20 May 2011 13:43|
|Last modified:||06 Aug 2016 00:06|