Design and preliminary experiment of radial sheet beam terahertz source based on radial pseudospark discharge

Abstract

To satisfy the demands for compact, inexpensive terahertz (THz) sources with power of hundreds of watts, a radial sheet beam THz source which does not require an external magnetic field and is driven by a radial pseudospark discharge plasma electron gun (PSDP-EGUN) is proposed. Radial design has been used in pseudospark switches, but in this paper the design of a PSDP-EGUN to drive a radial THz source is presented for the first time. Being different from the latest reported axial quasi-rectangular sheet beam THz sources driven by an axial PSDP-EGUN, a new design consisting of a circular plate-shaped sheet beam that is directly generated by the radial PSDP-EGUN is reported. As compared to an axial system, the radial configuration may result in a larger beam current and a larger beam-wave interaction area together with a higher potential of THz output power. Theoretical analysis and particle-in-cell simulation have been employed in the design of the radial sheet beam THz source. Output powers in the kilowatt range have been observed in the simulation of this 0.22 THz source. Preliminary experimental results of the radial PSDP-EGUN are also presented.