Transport of a relativistic electron beam in gas and plasma-filled focusing cells for X-ray radiography

Gas cells have been used in radiographic sources to assist in the focusing of intense electron beams, produced using pulsed-power accelerators, onto a high atomic number target to generate bremsstrahlung radiation. The quality of the resulting source increases linearly with the dose and inversely with the square of the spot size. Higher plasma conductivity in the cell could lead to an improved radiation source. Given a stable diode voltage, hybrid particle-in-cell simulations show improvement of the beam spot via preionization of the gas cell prior to arrival of the electron beam pulse.