Study Of The Hybrid X-Pinch With An External Axial Magnetic Field

Summary form only given. The hot spot that develops in the gap between the electrodes of a hybrid X-pinch (HXP) [1] is a unique source of X-rays. The hot spot location is within 100-1000 μm of the center of symmetry of the X-pinch, and uncertainty depends on the gap size. Investigation of the X-pinch neck cascade process [2] showed that the hot spot tended to develop on one side of the minidiode that constitutes the z-pinch electrode structure in an X-pinch. The addition of an axial magnetic field component as a means to shift the hot spot in a specific direction and to stabilize its location has been tested in HXP experiments on 250 kA-1.2 MA pulsers [3]. It was shown that a configuration with twisted return current rods can generate too strong an axial magnetic, seriously disturbing the neck cascade process and hot spot development. In this work we have been continuing to study magnetized HXBs using a large set of available diagnostics: laser probing, X-ray, XUV and optical imaging, tiny magnetic probes and X-ray spectroscopy. The magnetic field profile around an HXP with twisted return current rods was measured on BIN (270 kA current, 100 ns risetime) and COBRA (1.2 MA current, 100 ns risetime) pulsers and optimal for x-ray production axial/azimuthal magnetic field ratio was determined.