Speaker
Description
Recently, sheet electron beam traveling-wave tubes are actively researched in the terahertz regime (0.3 - 3 THz). Sheet electron beams have several advantages over conventional pencil beams such as higher beam current and more interaction space.
There are several challenges in using sheet electron beams. One of the difficulties of sheet electron beams is generation of low-emittance beam with planar cut cathode. Planar cathodes are used instead of cylindrical cut cathodes which has been used in lower frequency regime because of fabrication difficulty. Another difficulty is transport of the sheet electron beam in a narrow beam channel. Because of the diocotron instability, periodic magnetic fields such as periodically cusped magnet (PCM) and wiggler have been preferred to solenoidal magnetic fields, although some recent studies use solenoidal fields due to limitation in current permanent magnet technology.
In this work, we study the generation of a 11.7-kV, 40-mA, and 0.32-mm * 0.06-mm sheet electron beam with a planar cathode and elliptical shape focusing electrode. Also, the magnetic focusing system using a newly proposed non-symmetric periodic planar quadrupole magnets (PPQM) is studied. The characteristics of PPQM are studied and checked with simulations using CST Studio Suite.
