UCSB FEL ELECTRON GUNS

Type 1

photo of electron gun

photo of electron gun[gif 63K][jpeg 14K]

[gif 72K][jpeg 14K]

I=2A, E=50KV, eps_n=10pi mm-mr, cntrl:-2 to +10KV, exit:8mm,12mr

photo of electron gun pieces[gif 62K][jpeg 16K]

illustration of electron gun
trajectory plot
These guns are part of the UCSB FEL electron beam systems. One is installed in the 6 MV accelerator and the other is part of the 2 MV CW, MM-FEL project. This is a low-compression Pierce type gun optimized for minimum spherical aberation. It uses a thermionic dispenser cathode operated between 800 and 1000 deg C. A control electrode, conforming to an equipotential surface and operated between -2 KV and +10 KV, switches the beam in <100 ns.

Type 2

photo of electron gun[gif 61K] [jpeg 12K] I=20A, E=200KV, eps_n=~30pi mm-mr, cntrl:-15 to +15KV
illustration of electron gun
trajectory plot
These guns were developed for a defunct 2 stage FEL project. One was once used to provide a 3 Amp beam, but its quality was disappointing. The two existing guns are in storage and may be used for future development.