96 / 2023-04-13 16:54:01

Measurement of the energy fluence radiated by a Z-pinch X-ray source

z-pinch

Z-pinch loads on Qiangguang-I generator can produce soft x-ray energies of 40kJ with a spectrum from about 0.1 to 2keV. On-target energy fluence is ~100J/cm² when the test object is located 5cm far from the center of the Z-pinch load. In the paper a novel method for determining the energy fluence incident on the target is discussed. The measurement system consists of a pinhole array and a nickel foil bolometer, and the pinhole array is used to attenuate the x-ray flux in an achromatic manner. The principle of the pinhole image is analyzed and the parameters of the pinhole array is optimized. The pinhole array contains 31×51 100-μm-diameter pinholes, while the row space and the column space are 0.9mm and 0.6mm respectively. The attenuation coefficient of the pinhole array is 1.18×10^-4 when the array is 5cm far from the Z-pinch load center and the bolometer is 50cm far from the pinhole array. The results show the pinhole array is feasible to be used as an attenuator, furthermore, it can mitigate the non-uniformity of the radiation flux on the target when the z pinch x-ray source is distorted by MHD instability. The measured data on Qiangguang-I show that the energy fluence incident on the test object is inversely proportional to the square of the distance from the material to the source when the distance is bigger than 5cm.