Energy exchange between electromagnetic radiation and plasma is crucial for many applications, impacting both terrestrial and astrophysical phenomena. This project focuses on a regime where a plasma is irradiated by a high-intensity laser that makes plasma electrons ultra-relativistic, with the exchange mediated by collective effects. We will demonstrate the influence of two phenomena that arise from relativistic electron motion: azimuthal laser-driven plasma magnetic fields and shifts in the laser’s phase velocity. Our objective is to leverage an interplay of these effects to increase electron
energy gain without needing to increase laser intensity. An anticipated benefit of the increased electron energy is enhanced gamma-ray emission, induced by the plasma magnetic field.
To achieve our objective, we will combine the simulation and theoretical expertise at UCSD with the unique experimental capabilities and expertise developed at ELI-NP. To
achieve control over plasma density and phase velocity, we will use empty channels and two laser pulses. The first, lower-intensity laser will induce controlled channel expansion, while the second, high-intensity laser will accelerate electrons in the resulting plasma-filled channel.