In this paper we report on the generation of cold electron beams using a Cs3Sb photocathode grown by codeposition of Sb and Cs. By cooling the photocathode to 90 K we demonstrate a significant reduction in the mean transverse energy validating the long-standing speculation that the lattice temperature contributes to limiting the mean transverse energy or intrinsic emittance near the photoemission threshold, opening new frontiers in generating ultrabright beams. At 90 K, we achieve a record low intrinsic emittance of 0.2 μm (rms) per mm of laser spot diameter from an ultrafast (subpicosecond) photocathode with quantum efficiency greater than 7×10-5 using a visible laser wavelength of 690 nm.
|Original language||English (US)|
|Journal||Physical Review Special Topics - Accelerators and Beams|
|State||Published - Nov 30 2015|
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)
- Surfaces and Interfaces