The intense radiation gasM. Marklund1, 2, 3, P. K. Shukla1, 2, 3 and B. Eliasson3
1 Department of Physics, Umeå University - SE-901 87 Umeå, Sweden
2 Centre for Fundamental Physics, Rutherford Appleton Laboratory Chilton Didcot, Oxfordshire, OX11 0QX, UK
3 Institut für Theoretische Physik IV, Fakultät für Physik und Astronomie Ruhr-Universität Bochum - D-44780 Bochum, Germany
received 13 December 2004; accepted in final form 18 March 2005
published online 6 April 2005
We present a new dispersion relation for photons that are nonlinearly interacting with a radiation gas of arbitrary intensity due to photon-photon scattering. It is found that the photon phase velocity decreases with increasing radiation intensity, and it attains a minimum value in the limit of super-intense fields. By using Hamilton's ray equations, a self-consistent kinetic theory for interacting photons is formulated. The interaction between an electromagnetic pulse and the radiation gas is shown to produce pulse self-compression and nonlinear saturation. Implications of our new results are discussed.
42.55.Vc - X- and gamma-ray lasers.
12.20.Ds - Quantum electrodynamics: Specific calculations.
95.30.-k - Fundamental aspects of astrophysics.
© EDP Sciences 2005