Experimental simulation of Magnetized Target Fusion compression physics by a magnetized plasma jet impacting a gas target cloud*

Physics underlying magnetized target fusion is investigated using a method where reference frames are changed so that the imploding liner compressing a magnetized plasma is simulated  by a fast MHD-driven plasma jet (representing the magnetized plasma)  impacting a gas target cloud (representing the liner).  This method is non-destructive so very large numbers of shots are possible. Diagnostics include an axially translatable interferometer (density), Thomson scattering (density, temperature), a  magnetic probe array, spectrometers, and a radiated power detector. Detailed measurements indicate the impact causes jet plasma compression and heating as well as compression of the magnetic field frozen into the jet.  The temperature initially increases in a manner consistent with adiabatic scaling but then suddenly drops. Analysis indicates this drop happens because of radiation via powerful atomic line emission from neutral hydrogen atoms created by three-body recombination driven by the compression.  Numerical simulations show temperature increases similar to the experimental observations before the line emission occurs.  These results show that to attain high temperature compression must occur much faster than all radiative loss rates.