Interaction of Short Petawatt Laser Pulses with Plasma
- Theory and Simulations

Laserlab Europe Workshop

Georg-Christoph-Lichtenberg-Haus, Darmstadt
October 14 - 17, 2007 -
Registered Participants Information

Title:	Dr.
Last Name:	Di Piazza
First Name:	Antonino
E-Mail:	dipiazzampi-hd.mpg.de
Affiliation for Badge:	MPI für Kernphysik, Heidelberg
Institute:
Address (Street):	Saupfercheckweg 1
Postal Code, City:	69117
Country:	Germany
Phone:	06221516162
Fax:	06221516152
Author(s):	A. Di Piazza, K. Z. Hatsagortsyan, E. Lötstedt, U. D. Jentschura and C. H. Keitel
Institute(s):	Max-Planck-Institut fuer Kernphysik
Title:	QED effects in strong laser fields
Abstract:	In view of the ever-stronger laser fields available, it is becoming feasible to use them to probe the nonlinear properties of vacuum as predicted by Quantum Electrodynamics. In particular, we investigate here the stimulated elastic photon-photon scattering process and its experimental feasibility by employing the next generation petawatt laser systems. The related process of harmonic generation in the collision in vacuum of two strong laser fields is studied. Moreover, the importance of including the diffractive effects arising in the interaction between an x-ray probe and an intense, focused optical standing wave is pointed out. Due to diffraction the x-ray probe polarization plane results rotated by an amount that is shown to be measurable. The typical laser intensity at which these nonlinear effects are predicted to become apparent is of order of $I_cr\sim 10^{29}\;\text{W/cm$^2$}. A mechanism to enhance vacuum polarization effects at a given laser intensity by exploiting the dielectric properties of a cold plasma is also investigated. A decisive role in this sense is played by the singular dielectric behaviour of the plasma near the plasma frequency. Finally, the photon splitting process due to vacuum polarization in a laser field and the laser-assisted bremsstrahlung are considered and the possibility of their experimental observation is discussed.