Looks like the new tech here is a "traveling wave RF photogun" used to accelerate the electrons. Here's a preprint from 2020 by the researchers that I'm assumi

Looks like the new tech here is a "traveling wave RF photogun" used to accelerate the electrons. Here's a preprint from 2020 by the researchers that I'm assuming describes their tech: https://arxiv.org/abs/2009.00270 https://arxiv.org/abs/2009.00270 (Edit: Removed speculation that the system architecture was that of a free-electron laser. Presentation shared by philipkglass indicates it's something different.)