Foil MRT and X-pinch experiments on a MA linear transformer driver

Abstract

Summary form only given. X-pinch experiments are underway on the MAIZE Linear Transformer Driver (LTD) at the University of Michigan. The MAIZE LTD can supply 1 MA, 100 kV pulses with 100 ns risetime into a matched load. The x-pinch consists of a single 35-50 μm Al or Mo wire separated by conical electrodes, between two current return plates. The LTD is charged to +/-70 kV resulting in approximately 0.4-0.5 MA through the wire. Initial tests show multiple x-ray bursts over the length of the current pulse.The x-pinch will ultimately backlight the Magneto RayleighTaylor (MRT) instability on a planar Al foil. The foil load contains a 1 cm wide, 400 nm thick foil placed between two current return plates. Ongoing MRT experiments involve seeding the MRT instability with arrays of 30 micron holes micromachined in the foil by a 150 fs Ti:sapphire laser. Laser shadowgraphy has previously been used to image the seeded foil as well as determine the MRT growth rate.[1,2] Future plans for the x-pinch include placing it in parallel with the foil in order to more accurately image and characterize the MRT instability. Plans for a smaller 100-150 kA compact pinch driver are also in development; (see poster by YagerEliorraga at this conference).