Electrode Plasmas During Self-Magnetic-Pinch E-Beam Diode Operation

Framing camera images of optical emission spectra from self-magnetic-pinch (SMP) diodes are presented, which illustrate the evolution of the anode (A) and cathode (K) plasmas during diode operation. These data were taken one frame per shot at different times during the X-ray pulses of standard configuration SMPs fired on the RITS-6 pulsed power driver. The images display the output from a five-fiber array, observing emission from discrete intervals along the diode's axis of symmetry. The array output was passed through an imaging spectrograph before being captured by an intensified charge-coupled-device camera gating for 20 ns. The images provide a qualitative understanding of the relative densities and temperatures of the A-K plasmas as they cross the A-K gap and collapse the diode impedance, ceasing the X-ray output. The overwhelming majority of the emission was continuum in nature; line emission was observed while the continuum emission was still weak. The observations are briefly discussed in the context of future diode research.