Magnetic Field Measurements using Zeeman splitting on the SMP Diode at Sandia National Laboratories

Self-Magnetic Pinch (SMP) diode experiments are in progress at the RITS-6 accelerator (5-11 MV, 100-200 kA) at Sandia National Laboratories. A hollow cathode emits electrons through an approximately 1-cm vacuum A-K gap onto a high-Z material. The high current compresses the electron beam to a few mm spot for use in flash x-ray radiography.\footnote{K. Hahn, N. Bruner, M. D. Johnston, B.V. Oliver, et. al., IEEE Trans. Plasma Sci. 38 (2010) 2652-62.} Visible spectra of the diode plasma have been taken during the radiation pulse using a high resolution (0.6 A) spectrometer and a lens coupled fiber array focused across the anode surface of the diode. Zeeman splitting measurements of CIV and Al III suggest magnetic fields of 3-4 T a few mm off the diode axis. These measurements yield current density profiles near the target surface.