Beam Profile And Position Instability Of A Post-Accelerated Pseudospark-Sourced Electron Beam For An Extended Interaction Oscillator

The pseudospark discharge is a low-pressure gas discharge, that can generate extremely high currents within short rise times using a special hollow cathode structure 1, 2. The highquality electron beam has high current density and brightness and the ability to self-focus via ion channel focusing 3. Simulations have shown the pseudospark-sourced electron beam can propagate within background plasma of density $10 ^{14}- 10 ^{16} \mathrm {m}^{-3}$ with no applied guiding magnetic field 4, making it excellent for millimeter-wave generation 5. Singleshot electron beam pulses were imaged by a CCD camera measuring light emitted by electron beam impact on $\mathrm {a}50 \mu \mathrm {m}$ thickness stopping copper foil and phosphor screen. The high energy component beam profile has a Lorentzian distribution much smaller than the axial aperture size.