The first experimental observation of subpicosecond electron bunches originating from an ultracold source

https://phys.org/news/2023-05-experimental-subpicosecond-electron-bunches-ultracold.html

"photoionizing laser-cooled rubidium gas in a grating magneto-optical trap via a two-step process. In the self-compression point of this source, measured electron bunches as short as 735±7, combination of ionization and energy spread... increase ionization laser pulse length10X without impacting electron bunch length... use of narrow band and more precise laser wavelength... shorten pulses at expense of energy spreading through source or vice-versa... single-shot, ultrafast electron crystallography of proteins"

Related: Breakthrough Research Unveils New Method for Ultrahigh Power Laser Pulse Compression

https://news.unist.ac.kr/breakthrough-research-unveils-new-method-for-ultrahigh-power-laser-pulse-compression/