Electron-Positron Pair Production in Laser Fields
by Prof. Reinhard Alkofer (Univ. Graz)
Tuesday, May 8th, 2017 from 14:00 to 15:00 (Europe/Budapest)
at KFKI campus ( Bldg.1. Conference Room )
Electron-positron pair production in ultra-strong electric fields, the Sauter-Schwinger effect, is a long-standing theoretical prediction. It is expected that modern laser facilities will be able to test it in the near future. In this talk I will review recent work on the theoretical description of non-perturbative electron-positron pair production with a special emphasis on investigations performed in our group in Graz.
First, the field parameters to be achieved in some (planned) laser facilities like the European XFEL at DESY or in the Extreme Light Infrastructure (ELI) project will be shortly reviewed and compared to typical fields necessary for the Sauter-Schwinger effect to occur. The underlying idea of the Dynamically Assisted Schwinger Pair Production will be explained in some detail. In addition, the crossover from Sauter-Schwinger to multiphoton production ("nonperturbative threshold regime") will be analyzed with respect to a possible experimental verification. It is shown how the quite complex spectra of created pairs can be understood through an effective mass for the electrons and with the help of semi-classical ponderomotive forces. Last but not least, the effect of inhomogeneous magnetic fields will be discussed.