High Current Density Advanced Cold Cathode Experiments

We report the design, construction and initial operation of an advanced, high-current-density, field emission cathode facility. The facility is designed to examine the nanophysics of field emission from advanced Al, Ni, C, CsI, Mo, and other material cathodes that operate in the 1-1000 A/cm² regime. Operation is designed for UHV vacuum (10^-10 Torr) with bake-out provisions up to temperatures of 450 C for several days to eliminate any residual water vapor or other contaminants. Three pumps are used to achieve UHV vacuum. The first is a Varian scroll pump, working from atmospheric pressure to 10^-3 Torr. Then, a Varian turbo pump is used to reduce the pressure from ^-3 Torr to^-8 Torr, with an all-metal bakeable right 90-degree angle valve to cut off the turbo pump from the whole system after pumping. Finally, a 250L/S, VacIon pump brings the whole system to ^-8 Torr with 450 C baking