The role of ion production on the physics of small diameter rod-pinch electron beam diodes

Summary form only given. The rod pinch diode has shown promise in producing a small diameter (/spl sim/1 mm), high brightness (2-3 Roentgens@1 m, 1.8 MeV endpoint with 30 ns FWHM) X-ray source for flash radiography. Previous simulations and modeling have shown that the operation of these diodes is similar to a standard pinched-beam diode. At low voltages and currents, the self magnetic field can be ignored and the diode operates as a space-charge-limited cylindrical diode. However, at voltages high enough to exceed critical current, the self-magnetic field can no longer be ignored and the diode current is magnetically limited. In this magnetically limited regime the self-magnetic field pinches the beam to the end or the anode rod creating a very tightly pinched electron beam. In the paper, the particle-in-cell code MAGIC is used to study the role of ions on small diameter rod-pinch diodes. Where possible, the simulation results are compared directly to experiments and theoretical predictions.