Hollow microspheres as targets for staged laser-driven proton acceleration
2011 (English)In: New Journal of Physics, ISSN 1367-2630, Vol. 13, 013030- p.Article in journal (Refereed) Published
A coated hollow core microsphere is introduced as a novel targetin 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.
Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP), 2011. Vol. 13, 013030- p.
Research subject Physics
IdentifiersURN: urn:nbn:se:umu:diva-84242DOI: 10.1088/1367-2630/13/1/013030ISI: 000288903600030OAI: oai:DiVA.org:umu-84242DiVA: diva2:681048