Particle Acceleration and Advanced Light Sources (PAALS)
Summary
High-Energy Physics colliders provide a window into the basic building blocks of the universe. As the energy gain from conventional radiofrequency accelerator technology begins to plateau, advanced accelerator concepts become the only way to push particle energies to new levels where the boundaries in the understanding of the universe can be expanded.
PAALS proposed two flagship experiments:
Flying-Focus-Driven Laser-Plasma Accelerator for Single-Stage TeV-Class Electron Beams (PAALS1)
Multi-messenger probing of ultra-intense/relativistic light-matter interactions (PAALS2)
The NSF OPAL RI-1 project includes PAALS1 as a flagship experiment and PAALS2 as a future flagship experiment.
Science Mission
Enable faster electron acceleration to help us explore fundamental physics and the nature of our universe in new ways.
Accelerate ions to very high energies, exceeding 100 million electron volts (MeV), to enable the study of matter under extreme conditions, allowing for deeper insights into the nature and behavior of matter and energy.
Advance laser technologies to create ultra-intense, short laser pulses that can travel long distances without losing energy, making experiments more efficient.
Combine strong electron beams with intense laser beams to generate high-energy particles that help explore matter under extreme pressures and temperatures.
Flying-Focus-Driven Laser-Plasma Accelerator for Single-Stage TeV-Class Electron Beams
The image above, from an article by Kyle G. Miller et al., shows an OSIRIS simulation of a dephasingless laser wakefield accelerator. Contours of laser intensity (red/yellow), electron density (gray), and accelerating/decelerating wakefield (teal/pink) are shown. The first bubble (white) trails the laser pulse and is devoid of all but the trapped electrons.
Dephasingless laser wakefield acceleration (LWFA) driven by an achromatic flying focus is an original concept that is a disruptive technology with the potential to transform the field of laser-plasma acceleration (LPA) and more broadly advanced accelerators. Conventional LWFA approaches can accelerate electrons to high energies, but the maximum energy is constrained by the low plasma densities required to limit dephasing between the laser pulse and accelerated electrons. The achromatic flying focus is a new spatiotemporal focusing system that provides the ability to propagate a high-intensity laser pulse over meters at any velocity while maintaining a small focal spot and a near-transform-limited pulse duration. By controlling the velocity of a focal spot propagating in a plasma, a wakefield can be driven at the speed of light, thus eliminating dephasing. Initial simulations of this “dephasingless” LWFA with no dephasing between the laser pulse and accelerated electrons suggests that a 20-fs, 500-J laser (NSF OPAL) would be capable of accelerating electrons to TeV-class energies in a one-meter stage. This flagship experiment seeks to successfully demonstrate such a TeV-class LPA.
