Observation of anomalous soft x-ray emission from a turbulently heated high voltage θ-pinch

Soft x-ray emission from the Maryland high voltage θ-pinch is measured as a function of two experimental parameters which in effect determines the electron density in the initial plasma. The x-ray intensity increases rapidly as the electron density is lowered; however, the electron temperature deduced from thin foil absorption of these x rays does not vary significantly. The absolute intensity of these about 3-keV x rays is orders of magnitude larger than the calculated intensity of bremsstrahlung radiation. To enhance x-ray emission, we put a small Cu target in the plasma, and measure absorption characteristics and intensity of these target x rays also. The time of x-ray emission correlates with those of neutron emission and implosion of magnetic field on the axis.