Cherenkov interaction and post-acceleration experiments of high brightness electron beams from a pseudospark discharge

Abstract

A pseudospark-sourced electron beam has two phases, an initial hollow cathode phase (HCP) beam followed by a conductive phase (CP) beam. The beam brightness was measured by a field-free collimator to be 10 9 and 10 11 Am À2 rad À2 for HCP beam and CP beam, respectively. The initial HCP beam from an eight-gap pseudospark discharge was applied in a Cherenkov interaction between the electron beam and the TM 01 mode of a 60-cm long alumina-lined waveguide. While the CP beam from a three-gap pseudospark discharge chamber was propagated and post-accelerated from about 200 V to more than 40 kV.

Study of a 0.35 THz Extended Interaction Oscillator Driven by a Pseudospark-Sourced Sheet Electron Beam

“…It was first experimentally studied by Christiansen and Schultheiss in the late 1970's [22]. A self-sustained electron beam pulse can be produced with high-brightness, low emittance (~15 mm • mrad), small beam diameter (<4 mm), and fast current rise (up to 10 12 A/s), as well as high beam current density (~10 8 A/m 2 ) [23][24][25][26][27][28], which is catered to the requirement for high power sources of millimeter-wave and THz radiation, such as BWOs, EIOs, free-electron lasers (FELs). In the experiment, a PS electron beam current of 118 A was measured after propagating through a 60 mm long collimator of diameter 3.5 mm in diameter [29].…”

Compact high‐power millimetre wave sources driven by pseudospark‐sourced electron beams

“…The PS discharge goes through various complex discharge processes and depends primarily on the PS discharge configurations [24][25][26][27][28][29]. Since its discovery in 1978, efforts have been made to understand the PS discharge phenomena for the generation of high density and energetic electron beams by theoretical, plasma simulation, and experimental studies [9,18,24,[29][30][31][32][33][34][35][36][37][38]. Notably, PS discharges have been studied at the University of Strathclyde since 1994 with a series of experiments conducted on beam generation and microwave and millimetre wave sources driven by PS discharges.…”

Design of a 0.35 THz Extended Interaction Oscillator Based on Pseudospark-Sourced Sheet Electron Beam

“…In VEDs high quality intense electron beams are required as the frequency increases. This has resulted in the pseudospark (PS) discharge attracting a lot of attention as a promising source of high quality, high intensity electron beam pulses as the beam current densities of up to 10 8 A m -2 and brightness up to 10 12 A m -2 rad -2 have been reported [3][4][5][6][7]. A PS-sourced electron beam does not require the use of an external guide magnetic field as the beam is selffocused by ion channel focusing.…”