Title :
High current density results from a LaB6 thermionic cathode electron gun
Author :
Herniter, Marc E. ; Getty, Ward D.
Author_Institution :
Coll. of Eng. & Technol., Northern Arizona Univ., Flagstaff, AZ, USA
fDate :
12/1/1990 12:00:00 AM
Abstract :
A Pierce-type electron gun using a planar 1.9-cm-diameter lanthanum hexaboride cathode is being studied as a robust thermionic emitter at high cathode-current densities. The gun has been operated up to voltages of 115 kV, achieving beam current densities of 30 A/cm2 . The electron gun operated dependably up to 90 kV, achieving temperature-limited currents of 50 A. Due to the high fields at the tip of the Pierce-focusing electrode, the gun would usually arc at voltages >90 kV. Ten shots were obtained at a gun voltage of 115 kV, achieving transmitted currents up to 89 A, transmitted beam power up to 10.2 MW, and transmitted power densities up to 3.4 MW/cm2
Keywords :
electron guns; lanthanum compounds; thermionic cathodes; thermionic electron emission; 1.9 cm; 10.2 MW; 115 kV; 50 A; 90 kV; LaB6; Pierce-focusing electrode; Pierce-type electron gun; beam power; cathode-current densities; gun voltage; high current density; planar cathode; power densities; temperature-limited currents; thermionic cathode electron gun; thermionic emitter; transmitted currents; Boron; Cathodes; Current density; Electron emission; Heating; Lanthanum; Temperature; Thermionic emission; Tungsten; Voltage;
Journal_Title :
Plasma Science, IEEE Transactions on
