Compact all-optical plasma accelerators: From 10GeV electrons to future light sources

Laser-driven plasma accelerators (LPAs) offer a pathway to compact, high-gradient alternatives to conventional RF accelerators. Their ability to produce bright, ultrashort electron beams in centimeter- scale structures makes them promising drivers for applications ranging from high-energy physics to next-generation light sources. This talk will highlight recent advances at the BELLA Center. We first present the acceleration of high-quality electron beams beyond 10 GeV using petawatt-class laser pulses guided through 30-cm-long, low-density plasma waveguides [1]. Key to this advance was the development of low-density plasma waveguides formed by the hydrodynamic expansion of optical field ionized (HOFI) plasmas [2-4]. Using a new method to control the waveguide length on a shot-by-shot basis, we gained unprecedented insight into the physics of ultrashort, petawatt laser propagation through plasma waveguides, directly observing high order mode excitation and filtering, non-linear depletion of laser energy to the plasma, and laser pulse steepening. Secondly, we will discuss efforts towards applications of compact, laser-driven accelerators. We demonstrate greater than 1000x gain in a free-electron laser (FEL), marking the first consistent operation of an LPA-driven FEL [5]. Together, these advances represent critical steps toward compact accelerators that will drive ultrafast light sources for science and technology.

[1] A. Picksley et al., Phys. Rev. Lett (2024)

[2] R. Shalloo et al., Phys. Rev. E (2018)

[3] A. Picksley et al., Phys. Rev. E (2020)

[4] L. Feder et al., Phys. Rev. Research (2020)