Simulation of a collisionless planar electrostatic shock in a proton–electron plasma with a strong initial thermal pressure change
2010 (English)In: Plasma Physics and Controlled Fusion, ISSN 0741-3335, Vol. 52, no 2, 025001- p.Article in journal (Refereed) Published
The localized deposition of the energy of a laser pulse, as it ablates a solid target, introduces high thermal pressure gradients in the plasma. The thermal expansion of this laser-heated plasma into the ambient medium (ionized residual gas) triggers the formation of non-linear structures in the collisionless plasma. Here an electron–proton plasma is modelled with a particle-in-cell simulation to reproduce aspects of this plasma expansion. A jump is introduced in the thermal pressure of the plasma, across which the otherwise spatially uniform temperature and density change by a factor of 100. The electrons from the hot plasma expand into the cold one and the charge imbalance drags a beam of cold electrons into the hot plasma. This double layer reduces the electron temperature gradient. The presence of the low-pressure plasma modifies the proton dynamics compared with the plasma expansion into a vacuum. The jump in the thermal pressure develops into a primary shock. The fast protons, which move from the hot into the cold plasma in the form of a beam, give rise to the formation of phase space holes in the electron and proton distributions. The proton phase space holes develop into a secondary shock that thermalizes the beam.
Place, publisher, year, edition, pages
Bristol: Institute of Physics and IOP Publishing Limited , 2010. Vol. 52, no 2, 025001- p.
laser plasma, shock, electrostatic
Fusion, Plasma and Space Physics
IdentifiersURN: urn:nbn:se:liu:diva-53188DOI: 10.1088/0741-3335/52/2/025001OAI: oai:DiVA.org:liu-53188DiVA: diva2:287572