Monochromatic x-ray imaging is an essential method for plasma diagnostics related to density information.Large-field high-resolution monochromatic imaging of a He-like iron(Fe XXV)Kαcharacteristic line(6.701 keV)for ...Monochromatic x-ray imaging is an essential method for plasma diagnostics related to density information.Large-field high-resolution monochromatic imaging of a He-like iron(Fe XXV)Kαcharacteristic line(6.701 keV)for laser plasma diagnostics was achieved using a developed toroidal crystal x-ray imager.A high-index crystal orientation Ge(531)wafer with a Bragg angle of 75.37°and the toroidal substrate were selected to obtain sufficient diffraction efficiency and compensate for astigmatism under oblique incidence.A precise offline assembly method of the toroidal crystal imager based on energy substitution was proposed,and a spatial resolution of 3-7μm was obtained by toroidal crystal imaging of a 600 line-pairs/inch Au grid within an object field of view larger than 1.0 mm.The toroidal crystal x-ray imager has been successfully tested via side-on backlight imaging experiments of the sinusoidal modulation target and a 1000 line-pairs/inch Au grid with a linewidth of 5μm using an online alignment method based on dual positioning balls to indicate the target and backlighter.This paper describes the optical design,adjustment method,and experimental results of a toroidal crystal system in a laboratory and laser facility.展开更多
Curved crystal imaging is an important means of plasma diagnosis.Due to the short wavelengths of high-energy X rays and the fixed lattice constant of the spherical crystal,it is difficult to apply the spherical crysta...Curved crystal imaging is an important means of plasma diagnosis.Due to the short wavelengths of high-energy X rays and the fixed lattice constant of the spherical crystal,it is difficult to apply the spherical crystal in high-energy X-ray imaging.In this study,we have developed a high-energy,high-resolution X-ray imager based on a toroidal crystal that can effectively correct astigmatism.We prepared a Ge<511>toroidal crystal for backlighting Mo Kα1 characteristic lines(∼17.48 keV)and verified its high-resolution imaging ability in high-energy X-ray region,achieving a spatial resolution of 5–10μm in a field of view larger than 1.0 mm.展开更多
In this study,a toroidal quartz(2023)crystal is designed for monochromatic X-ray imaging at 72.3◦.The designed crystal produces excellent images of a laser-produced plasma emitting He-like Ti X-rays at 4.75 keV.Based ...In this study,a toroidal quartz(2023)crystal is designed for monochromatic X-ray imaging at 72.3◦.The designed crystal produces excellent images of a laser-produced plasma emitting He-like Ti X-rays at 4.75 keV.Based on the simulations,the imaging resolutions of the spherical and toroidal crystals in the sagittal direction are found to be 15 and 5μm,respectively.Moreover,the simulation results show that a higher resolution image of the source can be obtained by using a toroidal crystal.An X-ray backlight imaging experiment is conducted using 4.75 keV He-like Ti X-rays,a 3×3 metal grid,an imaging plate and a toroidal quartz crystal with a lattice constant of 2d=0.2749 nm.The meridional and sagittal radii of the toroidalα-quartz crystal are 295.6 and 268.5 mm,respectively.A highly resolved image of the microgrid,with a spatial resolution of 10μm,is obtained in the experiment.By using similar toroidal crystal designs,the application of a spatially resolved spectrometer with high-resolution X-ray imaging ability is capable of providing imaging data with the same magnification ratio in the sagittal and meridional planes.展开更多
The change in the toroidal rotation of plasma caused by electron cyclotron wave(ECW) injection has been observed in EAST. It is found that the response of the rotation is similar for all possible ECW toroidal inject...The change in the toroidal rotation of plasma caused by electron cyclotron wave(ECW) injection has been observed in EAST. It is found that the response of the rotation is similar for all possible ECW toroidal injection angles. The core toroidal rotation velocity increases in the co-current direction along with a rise in the plasma temperature and stored energy. The profile of the electron temperature, ion temperature and toroidal rotation velocity gradually become peaked.The change in toroidal rotation in the core increases with the ECW injection power. Different behavior is observed when the ECWs are injected into low hybrid current drive(LHCD) target plasmas, where the electron temperature and rotation profile become peaked, while the ion temperature profile flattens after ECW injection, suggesting different transport characteristics in energy and momentum.展开更多
Core plasma rotation of both L-mode and H-mode discharges with ion cyclotron range of frequency(ICRF) minority heating(MH) scheme was measured with a tangential X-ray imaging crystal spectrometer on EAST(Experime...Core plasma rotation of both L-mode and H-mode discharges with ion cyclotron range of frequency(ICRF) minority heating(MH) scheme was measured with a tangential X-ray imaging crystal spectrometer on EAST(Experimental Advanced Superconducting Tokamak).Cocurrent central impurity toroidal rotation change was observed in ICRF-heated L-and H-mode plasmas.Rotation increment as high as 30 km/s was generated at ~1.7 MW ICRF power.Scaling results showed similar trend as the Rice scaling but with significant scattering,especially in L-mode plasmas.We varied the plasma current,toroidal field and magnetic configuration individually to study their effect on L-mode plasma rotation,while keeping the other major plasma parameters and heating unchanged during the scanning.It was found that larger plasma current could induce plasma rotation more efficiently.A scan of the toroidal magnetic field indicated that the largest rotation was obtained for on-axis ICRF heating.A comparison between lower-single-null(LSN)and double-null(DN) configurations showed that LSN discharges rendered a larger rotation change for the same power input and plasma parameters.展开更多
基金National Natural Science Foundation of China(No.11805212)National Key Research and Development Program of China(No.2019YFE03080200)。
文摘Monochromatic x-ray imaging is an essential method for plasma diagnostics related to density information.Large-field high-resolution monochromatic imaging of a He-like iron(Fe XXV)Kαcharacteristic line(6.701 keV)for laser plasma diagnostics was achieved using a developed toroidal crystal x-ray imager.A high-index crystal orientation Ge(531)wafer with a Bragg angle of 75.37°and the toroidal substrate were selected to obtain sufficient diffraction efficiency and compensate for astigmatism under oblique incidence.A precise offline assembly method of the toroidal crystal imager based on energy substitution was proposed,and a spatial resolution of 3-7μm was obtained by toroidal crystal imaging of a 600 line-pairs/inch Au grid within an object field of view larger than 1.0 mm.The toroidal crystal x-ray imager has been successfully tested via side-on backlight imaging experiments of the sinusoidal modulation target and a 1000 line-pairs/inch Au grid with a linewidth of 5μm using an online alignment method based on dual positioning balls to indicate the target and backlighter.This paper describes the optical design,adjustment method,and experimental results of a toroidal crystal system in a laboratory and laser facility.
基金supported by the National Key Research and Development Program of China(No.2019YFE03080200)the National Natural Science Foundation of China(Nos.11875202 and 11875048).
文摘Curved crystal imaging is an important means of plasma diagnosis.Due to the short wavelengths of high-energy X rays and the fixed lattice constant of the spherical crystal,it is difficult to apply the spherical crystal in high-energy X-ray imaging.In this study,we have developed a high-energy,high-resolution X-ray imager based on a toroidal crystal that can effectively correct astigmatism.We prepared a Ge<511>toroidal crystal for backlighting Mo Kα1 characteristic lines(∼17.48 keV)and verified its high-resolution imaging ability in high-energy X-ray region,achieving a spatial resolution of 5–10μm in a field of view larger than 1.0 mm.
基金supported by the National Natural Science Foundation of China(Nos.61604028,11775203,and 12075219)the Chongqing Study Abroad Innovation Fund Project(No.cx2018023)+1 种基金the Plasma Physics Key Laboratory Fund Project(No.6142A04180207)the Innovation and Development Fund of China Academy of Engineering Physics(No.CX20210019)。
文摘In this study,a toroidal quartz(2023)crystal is designed for monochromatic X-ray imaging at 72.3◦.The designed crystal produces excellent images of a laser-produced plasma emitting He-like Ti X-rays at 4.75 keV.Based on the simulations,the imaging resolutions of the spherical and toroidal crystals in the sagittal direction are found to be 15 and 5μm,respectively.Moreover,the simulation results show that a higher resolution image of the source can be obtained by using a toroidal crystal.An X-ray backlight imaging experiment is conducted using 4.75 keV He-like Ti X-rays,a 3×3 metal grid,an imaging plate and a toroidal quartz crystal with a lattice constant of 2d=0.2749 nm.The meridional and sagittal radii of the toroidalα-quartz crystal are 295.6 and 268.5 mm,respectively.A highly resolved image of the microgrid,with a spatial resolution of 10μm,is obtained in the experiment.By using similar toroidal crystal designs,the application of a spatially resolved spectrometer with high-resolution X-ray imaging ability is capable of providing imaging data with the same magnification ratio in the sagittal and meridional planes.
基金supported by the National Magnetic Confinement Fusion Science Program of China (2013GB112004, 2015GB103002)National Natural Science Foundation of China (11305212, 11405212)+1 种基金the MajorProgram of Development Foundation of Hefei Center for Physical Science and Technology (2016FXZY008)the Natural Science Research Key Project of the Education Department of Anhui Province under grant No. KJ2016A434
文摘The change in the toroidal rotation of plasma caused by electron cyclotron wave(ECW) injection has been observed in EAST. It is found that the response of the rotation is similar for all possible ECW toroidal injection angles. The core toroidal rotation velocity increases in the co-current direction along with a rise in the plasma temperature and stored energy. The profile of the electron temperature, ion temperature and toroidal rotation velocity gradually become peaked.The change in toroidal rotation in the core increases with the ECW injection power. Different behavior is observed when the ECWs are injected into low hybrid current drive(LHCD) target plasmas, where the electron temperature and rotation profile become peaked, while the ion temperature profile flattens after ECW injection, suggesting different transport characteristics in energy and momentum.
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2013GB112004 and 2015GB103002)National Natural Science Foundation of China(Nos.11175208,11305212,11375235,11405212 and 11261140328)+1 种基金the Innovative Program of Development Foundation of Hefei Center for Physical Science and Technology(2014FXCX003)Brain Korea 21 Program for Leading Universities&Students(BK21 PLUS)
文摘Core plasma rotation of both L-mode and H-mode discharges with ion cyclotron range of frequency(ICRF) minority heating(MH) scheme was measured with a tangential X-ray imaging crystal spectrometer on EAST(Experimental Advanced Superconducting Tokamak).Cocurrent central impurity toroidal rotation change was observed in ICRF-heated L-and H-mode plasmas.Rotation increment as high as 30 km/s was generated at ~1.7 MW ICRF power.Scaling results showed similar trend as the Rice scaling but with significant scattering,especially in L-mode plasmas.We varied the plasma current,toroidal field and magnetic configuration individually to study their effect on L-mode plasma rotation,while keeping the other major plasma parameters and heating unchanged during the scanning.It was found that larger plasma current could induce plasma rotation more efficiently.A scan of the toroidal magnetic field indicated that the largest rotation was obtained for on-axis ICRF heating.A comparison between lower-single-null(LSN)and double-null(DN) configurations showed that LSN discharges rendered a larger rotation change for the same power input and plasma parameters.