Speaker
Description
Sources of high-energy, dense and collimated photon and lepton beams enable new avenues for research in strong-field QED and relativistic laboratory astrophysics 1-2.
Here we show that a high-current ultrarelativistic electron beam interacting with multiple thin conducting foils can undergo strong self-focusing accompanied by efficient emission of gamma-ray synchrotron photons. Physically, self-focusing and high-energy photon emission originate from the beam interaction with the near-field transition radiation accompanying the beam-foil collision. This near field radiation is of strength comparable with the beam self-field, and can be strong enough that a single emitted photon can carry away a significant fraction of the emitting electron energy. After beam collision with multiple foils, collimated electron and photon beams with number density exceeding that of a solid are obtained 3.
The relative simplicity, unique properties, and high efficiency of this gamma-ray source open up new opportunities for both applied and fundamental research including laserless investigations of strong-field QED processes with a single electron beam 3 and the generation of dense electron-positron jets that are essential for laboratory astrophysics investigations of electron-positron plasma 1-2.
Based on these findings, the E-332 experiment on solid-density gamma-ray pulse generation in electron beam-multifoil interaction has been developed and approved with maximal ranking, and will be carried out at the FACET-II facility at SLAC.
Finally, we show that high-energy and dense lepton beams enable precision studies of fundamental quantum processes in the supercritical QED regime, where the beam particles experience rest-frame electromagnetic fields which greatly exceed the QED critical one 4.
References
1 R. Ruffini et al., Phys. Rep. 487, 1 (2010)
2 A. Di Piazza et al., Rev. Mod. Phys. 84, 1177 (2012)
3 A. Sampath et al., Phys. Rev. Lett. 126, 064801 (2021)
4 M. Tamburini et al., arXiv:1912.07508
