198 / 2023-04-15 18:53:54

Experimental measurement of the velocity of Aluminum foils driven by the tense pulse soft X-ray radiation

Z-pinch,PDV,tense pulse soft X-ray,Velocimetry

极端光下的基础物理学 > 极端光下的基础物理学-海报

    When large current fed to the cylinder fine-wire array, pulsed tense soft X-rays would be emitted from the high energy density plasma which generated by the wire array Z-pinch. A series of effects would be appeared when strong X-ray impact the objects, such as Aluminum foil samples. Incident radiation deposited a mass of energy into the foils’ surface, heating and vaporizing the materials near the surface instantaneously, and leading to blowoff, pressure wave propagation, structure deformation, etc. For studying materials impulse response to the pulse tense soft X-ray irradiation, we need detect the velocity history of particles on the free surface of the samples and eventually the whole sample motion. A PDV (Photon Doppler Velocimetry) system was developed and utilized to conduct the velocity measurement. Al foils which collided by tense pulse soft X-rays emitting from aluminum wire arrays Z-pinch source, which radiation emissions mostly distribute from 0.1-10 kev, on the pulse power(~8 MA, ~60 ns) facility. The PDV monitored the center of rear-surface of the sample,which ~2 mm thick and 10 mm diameter, and recorded more than 120 μs velocity history of the point since the pinch burst. With the pinch fluence ~0.3 kJ/cm², duration ~20 ns, incident radiation generated pressures in the foils about 4 GPa which deduced from the velocity of the sample free surface, ~0.3km/s, measured by PDV. From the PDV velocity curve, about 20 μs after the front-surface exposed to Z-pinch radiation flux, the whole sample motion eventually reached about 200 m/s after the shock unloading.