A high energy X-ray digital radiography(DR)nondestructive testing(NDT)system has been developed to detect the operating state of a driving mechanism.The system consists of five main subsystems,namely,X-ray generator,i...A high energy X-ray digital radiography(DR)nondestructive testing(NDT)system has been developed to detect the operating state of a driving mechanism.The system consists of five main subsystems,namely,X-ray generator,image intensifier,image processor,mechanical platform and control subsystem.Owning to the mechanical platform,the X-ray generator and image intensifier are able to rotate around the vertical axis from 0°to 360°in 35 s and move along vertical axis within the range of 500 mm in 20 s.The 450 kV X-ray generator provides a maximum 100 mm penetration depth and a coverage angle of 40°,and the resolution of the scanned image is 66 lp/cm.As is indicated by its applications,the system is featured with fast scanning speed,wide detection range and high imaging quality.It can be applied to inspect the defects in the driving mechanism as well.展开更多
Laser-solid interactions are highly suited as a potential source of high energy X-rays for nondestructive imaging.A bright,energetic X-ray pulse can be driven from a small source,making it ideal for high resolution X-...Laser-solid interactions are highly suited as a potential source of high energy X-rays for nondestructive imaging.A bright,energetic X-ray pulse can be driven from a small source,making it ideal for high resolution X-ray radiography.By limiting the lateral dimensions of the target we are able to confine the region over which X-rays are produced,enabling imaging with enhanced resolution and contrast.Using constrained targets we demonstrate experimentally a(20±3)μm X-ray source,improving the image quality compared to unconstrained foil targets.Modelling demonstrates that a larger sheath field envelope around the perimeter of the constrained targets increases the proportion of electron current that recirculates through the target,driving a brighter source of X-rays.展开更多
We report on the design and first results from experiments looking at the formation of radiative shocks on the ShenguangII(SG-II)laser at the Shanghai Institute of Optics and Fine Mechanics in China.Laser-heating of a...We report on the design and first results from experiments looking at the formation of radiative shocks on the ShenguangII(SG-II)laser at the Shanghai Institute of Optics and Fine Mechanics in China.Laser-heating of a two-layer CH/CH–Br foil drives a∼40 km/s shock inside a gas cell filled with argon at an initial pressure of 1 bar.The use of gas-cell targets with large(several millimetres)lateral and axial extent allows the shock to propagate freely without any wall interactions,and permits a large field of view to image single and colliding counter-propagating shocks with time-resolved,pointprojection X-ray backlighting(∼20µm source size,4.3 keV photon energy).Single shocks were imaged up to 100 ns after the onset of the laser drive,allowing to probe the growth of spatial nonuniformities in the shock apex.These results are compared with experiments looking at counter-propagating shocks,showing a symmetric drive that leads to a collision and stagnation from∼40 ns onward.We present a preliminary comparison with numerical simulations with the radiation hydrodynamics code ARWEN,which provides expected plasma parameters for the design of future experiments in this facility.展开更多
文摘A high energy X-ray digital radiography(DR)nondestructive testing(NDT)system has been developed to detect the operating state of a driving mechanism.The system consists of five main subsystems,namely,X-ray generator,image intensifier,image processor,mechanical platform and control subsystem.Owning to the mechanical platform,the X-ray generator and image intensifier are able to rotate around the vertical axis from 0°to 360°in 35 s and move along vertical axis within the range of 500 mm in 20 s.The 450 kV X-ray generator provides a maximum 100 mm penetration depth and a coverage angle of 40°,and the resolution of the scanned image is 66 lp/cm.As is indicated by its applications,the system is featured with fast scanning speed,wide detection range and high imaging quality.It can be applied to inspect the defects in the driving mechanism as well.
基金supported by EPSRC grants EP/K022415/1and EP/R006202/1the STFC IPS grant ST/P000177/1
文摘Laser-solid interactions are highly suited as a potential source of high energy X-rays for nondestructive imaging.A bright,energetic X-ray pulse can be driven from a small source,making it ideal for high resolution X-ray radiography.By limiting the lateral dimensions of the target we are able to confine the region over which X-rays are produced,enabling imaging with enhanced resolution and contrast.Using constrained targets we demonstrate experimentally a(20±3)μm X-ray source,improving the image quality compared to unconstrained foil targets.Modelling demonstrates that a larger sheath field envelope around the perimeter of the constrained targets increases the proportion of electron current that recirculates through the target,driving a brighter source of X-rays.
基金the Royal Society(UK)through a University Research Fellowship(URF-R-180032)a Research Fellows Enhancement Award(RGF-EA-180240)+2 种基金an International Exchanges grant(IES-R3-170140)a Research Grant(RG2017-R2)The authors would like to thank the operation group of the SG-II laser facility.C.S.acknowledges support from the French INSU-PNPS programme.U.C.acknowledges support by the project Advanced Research(CZ.02.1.01/0.0/0.0/16_019/0000789)from European Regional Development Fund(ADONIS)。
文摘We report on the design and first results from experiments looking at the formation of radiative shocks on the ShenguangII(SG-II)laser at the Shanghai Institute of Optics and Fine Mechanics in China.Laser-heating of a two-layer CH/CH–Br foil drives a∼40 km/s shock inside a gas cell filled with argon at an initial pressure of 1 bar.The use of gas-cell targets with large(several millimetres)lateral and axial extent allows the shock to propagate freely without any wall interactions,and permits a large field of view to image single and colliding counter-propagating shocks with time-resolved,pointprojection X-ray backlighting(∼20µm source size,4.3 keV photon energy).Single shocks were imaged up to 100 ns after the onset of the laser drive,allowing to probe the growth of spatial nonuniformities in the shock apex.These results are compared with experiments looking at counter-propagating shocks,showing a symmetric drive that leads to a collision and stagnation from∼40 ns onward.We present a preliminary comparison with numerical simulations with the radiation hydrodynamics code ARWEN,which provides expected plasma parameters for the design of future experiments in this facility.
