Probing Super-Critical Electromagnetic Fields with Petawatt Lasers

This project supports efforts to design experiments for the new National Science Foundation-funded high intensity Zettawatt-Equivalent Ultrashort pulse laser System (ZEUS) facility. High peak-power lasers, such as the ZEUS multi-Petawatt laser can generate extreme electromagnetic fields through focusing the power down to a tiny spot. These fields are capable of accelerating charged particles to near the speed of light in a fraction of a million billionth of a second, producing bright, point-like sources of radiation.

In such strong fields, high-energy gamma-rays can spontaneously decay into pairs of matter-antimatter particles, leading to matter creation from light. This project will design experiments for the ZEUS facility to measure matter creation and amplification of the process through a chain reaction. The project will support graduate students and should enable a study of dense and ultrashort duration beams of antimatter.

The ZEUS laser facility will generate few-gigaelectronvolt electron beams through laser wakefield acceleration, which is a method for generating beams of electrons using the accelerating field structure produced in a plasma in the wake of a high-power, ultrashort pulsed laser. By colliding the electron beam with a second, tightly focused, high-power laser pulse, the field strength is expected to greatly exceed the critical field of quantum electrodynamics in the electron rest frame, leading to electron-positron pair production.

Graduate students will participate in designing and building particle detectors for ZEUS experiments, the plasma target for controlled injection of stable monoenergetic beams and guiding of the laser to achieve multi-GeV energies, and modelling the laser-electron collision physics using advanced quantum kinetic codes. Understanding the laser interaction physics is crucial for the frontier ZEUS experiments to be successful.

In the final year of the project, laser time with ZEUS is anticipated to be available for the first runs for this frontier experiment.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.