Monochromatic flash embossed radiography using clean K photons from a spherical-plasma target

摘要

Embossed radiography is an important technique for imaging target region by decreasing absorption contrast of objects. The monochromatic flash embossed radiography (M-FER) system consists of a computed radiography system, an intense plasma flash X-ray generator, and a two-dimensional subtraction program for shifting the image pixel. In the flash X-ray generator, a high-voltage condenser of 150 nF is charged to 80 kV, and the electric charges in the condenser are discharged to the flash X-ray tube through a four-cable transmission line after closing the gap switch. The molybdenum-target evaporation leads to the formation of weakly ionized spherical plasma, and intense molybdenum K-series characteristic X-rays (K-rays) were produced utilizing angular dependence of bremsstrahlung X-ray intensity. High-speed monochromatic radiography was performed using molybdenum flash K-rays, and M-FER was carried out utilizing single-energy subtraction after the image shifting. The spatial resolutions of the horizontal and vertical directions were both 125 μm, and monochromatic concavoconvex radiography such as phase-differential imaging was performed with X-ray durations of approximately 100 ns.