Volume 83, Number 1, July 2008
Article Number 15002
Number of page(s) 6
Section Physics of Gases, Plasmas and Electric Discharges
Published online 12 June 2008
EPL, 83 (2008) 15002
DOI: 10.1209/0295-5075/83/15002

A reduced coupled-mode description for the electron-ion energy relaxation in dense matter

G. Gregori1, 2 and D. O. Gericke3

1  Clarendon Laboratory, Department of Physics, University of Oxford - Parks Road, Oxford OX1 3PU, UK
2  Central Laser Facility, Rutherford Appleton Laboratory - Didcot OX11 0QX, UK
3  Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick Coventry CV4 7AL, UK

received 31 March 2008; accepted in final form 14 May 2008; published July 2008
published online 12 June 2008

We present a simplified model for the electron-ion energy relaxation in dense two-temperature systems that includes the effects of coupled collective modes. It also extends the standard Spitzer result to both degenerate and strongly coupled systems. Starting from the general coupled-mode description, we are able to solve analytically for the temperature relaxation time in warm dense matter and strongly coupled plasmas. This was achieved by decoupling the electron-ion dynamics and by representing the ion response in terms of the mode frequencies. The presented reduced model allows for a fast description of temperature equilibration within hydrodynamic simulations and an easy comparison for experimental investigations. For warm dense matter, both fluid and solid, the model gives a slower electron-ion equilibration than predicted by the classical Spitzer result.

52.38.-r - Laser-plasma interactions.
51.70.+f - Optical and dielectric properties.
61.20.-p - Structure of liquids.

© EPLA 2008