Design and Discharge Characterization of Pseudospark Discharge Based Plasma Cathode Electron Source for High Density and Energetic Short Pulsed e-beam Generation

In the present research work simulation and experimental investigations have been carried out for discharge characterization of single to multi-gap pseudospark discharge-based plasma cathode electron (PD-PCE) source for the generation of high-density and energetic pulsed electron beam. The developed PD-PCE source has been operated with different gases (Ar, N
2
, He), applied voltages (5-35 kV), and electrode aperture sizes (2-6 mm). The proposed analysis has helped for the design and development of multi-gap (4-gap) PD-PCE sources having uniform sequence of electrode apertures (SEA) diameters (2 -4 mm) for pulsed electron beam generation. The pre-breakdown, hollow cathode and conductive phases have been analyzed and found their dependency on the operating and circuit parameters. The generation of high density $(\sim 3.0\times 10^{5} {\mathrm {A}}/{\mathrm {cm}}^{2}$) and up to 32 kV pulsed electron beams are governed by the penetrated dynamic equipotential lines in the 4-gap PD-PCE source having uniform electrodes aperture diameter of 2 mm. In addition, it also facilitates the generation of the high pulsed electron beam current of $\sim 1.5$ kA with the current density of $\sim 1.0 {\mathrm {x}} 10^{4} {\mathrm {A}}/{\mathrm {cm}}^{2}$ at $\sim 35$ kV applied voltage with the 4 mm electrode aperture. These studies would be very much beneficial for the generation of short pulsed electron beams for EUV/soft X-ray radiation and surface modification of materials.