https://phys.org/news/2020-04-laser-technique-powerfuland-smallerparticle.html By observing electrons that have been accelerated to extremely high energies, scientists are able to unlock clues about the particles that make up our universe. Accelerating electrons to such high energies in a laboratory setting, however, is challenging: typically, the more energetic the electrons, the bigger the particle accelerator. For instance, to discover the Higgs boson—the recently observed "God particle," responsible for mass in the universe—scientists at the CERN laboratory in Switzerland used a particle accelerator nearly 17 miles long. But what if there was a way to scale down particle accelerators, producing high-energy electrons in a fraction of the distance? In a paper published in Physical Review Letters, scientists at the University of Rochester's Laboratory for Laser Energetics (LLE) outlined a method to shape intense laser light in a way that accelerates electrons to record energies in very short distances: the researchers estimate the accelerator would be 10,000 times smaller than a proposed setup recording similar energy, reducing the accelerator from nearly the length of Rhode Island to the length of a dining room table. With such a technology, scientists could perform tabletop experiments to probe the Higgs boson or explore the existence of extra dimensions and new particles that could lead to Albert Einstein's dream of a grand unified theory of the universe. more at link..... the paper: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.124.134802 ABSTRACT Laser wakefield accelerators (LWFAs) produce extremely high gradients enabling compact accelerators and radiation sources but face design limitations, such as dephasing, occurring when trapped electrons outrun the accelerating phase of the wakefield. Here we combine spherical aberration with a novel cylindrically symmetric echelon optic to spatiotemporally structure an ultrashort, high-intensity laser pulse that can overcome dephasing by propagating at any velocity over any distance. The ponderomotive force of the spatiotemporally shaped pulse can drive a wakefield with a phase velocity equal to the speed of light in vacuum, preventing trapped electrons from outrunning the wake. Simulations in the linear regime and scaling laws in the bubble regime illustrate that this dephasingless LWFA can accelerate electrons to high energies in much shorter distances than a traditional LWFA—a single 4.5 m stage can accelerate electrons to TeV energies without the need for guiding structures.
