Tabletop multi-mode z-pinch X-ray source "Sparky"

Summary form only given. A preliminary study of a tabletop multi-mode z-pinch X-ray source is presented. The goal of development of this device was to obtain high densities and temperatures in plasmas of high atomic number elements with two different types of loads: vacuum spark and small (micron-scale) wires. In the first mode, the device can be used for X-ray spectroscopic research and calibration of X-ray and vacuum ultraviolet (VUV) diagnostics instrumentation. In the second mode, single wire and X-pinch loads were applied. The device was developed on the basis of a VUV calibration source developed under a previous Sandia contract, and subsequently transferred to UNR. The existing system was substantially modified to lower the inductance and increase reliability. The system uses a railgap switch, a low-inductance vacuum interface, and a low-voltage (<25 kV), low-impedance, vacuum coaxial transmission line. Circuit modeling of the modified system predicted more than 100 kA into a plasma load from its DC-charged 3 microfarad, 25 kV capacitor bank, with a time to peak current of about 700 ns. This system is compact, and uses no transformer oil or deionized water. The total energy stored in the capacitors bank is up to 800 J with a charge voltage of up to 25 kV. The measured time to peak current is near 700 ns, and typical maximum current of 100-110 kA. The X-ray output energy, pulse duration, and X-ray images from this plasma source were studied with PCD and XRD diodes and a time-gated pinhole camera.