Fast collisional electron heating and relaxation in thin foils driven by a circularly polarized ultraintense short-pulse laser
Artikel i vetenskaplig tidskrift, 2020

The creation of well-thermalized, hot and dense plasmas is attractive for warm dense matter studies. We investigate collisionally induced energy absorption of an ultraintense and ultrashort laser pulse in a solid copper target using particle-in-cell simulations. We find that, upon irradiation by a 2 x 10(20) Wcm(-2) intensity, 60 fs duration, circularly polarized laser pulse, the electrons in the collisional simulation rapidly reach a well-thermalized distribution with similar to 3 :5 keV temperature, while in the collisionless simulation the absorption is several orders of magnitude weaker. Circular polarization inhibits the generation of suprathermal electrons, while ensuring efficient bulk heating through inverse bremsstrahlung, a mechanism usually overlooked at relativistic laser intensity. An additional simulation, taking account of both collisional and field ionization, yields similar results: the bulk electrons are heated to similar to 2:5 keV, but with a somewhat lower degree of thermalization than in the pre-set, fixed-ionization case. The collisional absorption mechanism is found to be robust against variations in the laser parameters. At fixed laser pulse energy, increasing the pulse duration rather than the intensity leads to a higher electron temperature.

plasma heating

plasma simulation

plasma dynamics

Författare

Andréas Sundström

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

Laurent Gremillet

Le Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA)

Evangelos Siminos

Göteborgs universitet

Istvan Pusztai

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

Journal of Plasma Physics

0022-3778 (ISSN) 1469-7807 (eISSN)

Vol. 86 2 755860201

Ämneskategorier

Atom- och molekylfysik och optik

Annan fysik

Den kondenserade materiens fysik

DOI

10.1017/S0022377820000264

Mer information

Senast uppdaterat

2020-08-19