Accelerator Seminar: Inverted-Insulator Photoelectron guns at Jefferson Lab
Speaker: Carlos Hernandez-Garcia, Thomas Jefferson National Accelerator Facility
Location: Auditorium
Time: 14:00
At Jefferson Lab, we have developed a compact DC high voltage photogun that relies on an inverted-insulator geometry. This design helps promote exceptional vacuum because there is less surface area to contribute a gas load, which is very beneficial when using delicate GaAs photocathodes for applications requiring polarized beam. And because the insulator serves as the cathode electrode support structure, it helps to minimize field emission because there is less metal biased at high voltage. And finally, a bulky SF6 tank is not required at the photogun, because a high voltage cable is used to apply high voltage. In this talk, I provide an overview of the inverted insulator geometry photogun and describe the applications that benefit from this gun design at Jefferson Lab: spin polarized beam generation from GaAs photocathodes at the CEBAF nuclear physics accelerator and at a compact 10 MeV accelerator, and magnetized beam generation using alkali-antomonide photocathodes.