Dramatic advances in laser technologies are enabling novel studies to explore laser-matter interactions at ultrahigh intensity. By focusing high-power laser pulses, electric fields (of orders of magnitude greater than found within atoms) are routinely produced and soon may be sufficiently intense to create matter from light.
Now, intriguing calculations from a research team at the Institute of Applied Physics of the Russian Academy of Sciences (IAP RAS), and reported this week in Physics of Plasmas, explain the production and dynamics of electrons and positrons from ultrahigh-intensity laser-matter interactions.
The electron-positron pair production accompanying interaction of a circularly polarized laser pulse with a foil is studied for laser intensities higher than 1024 W cm−2. The laser energy penetrates into the foil due to the effect of the relativistic hole-boring. It is demonstrated that the electron-positron plasma is produced as a result of quantum-electrodynamical cascading in the field of the incident and reflected laser light in front of the foil. The incident and reflected laser light make up the circularly polarized standing wave in the reference frame of the hole-boring front and the pair density peaks near the nodes and anti-nodes of the wave. A model based on the particle dynamics with radiation reaction effect near the magnetic nodes is developed. The model predictions are verified by three dimensional particle-in-cell Monte Carlo simulations.