A soft X-ray energy materials research beamline(BL20U2),a branch of energy materials beamline(E-line),has been constructed in the Shanghai Synchrotron Radiation Facility(SSRF)Phase-II project.It is now operational for...A soft X-ray energy materials research beamline(BL20U2),a branch of energy materials beamline(E-line),has been constructed in the Shanghai Synchrotron Radiation Facility(SSRF)Phase-II project.It is now operational for soft X-ray resonant emission spectroscopy(RXES)and soft X-ray resonant elastic scattering(REXS)investigations.Optical optimization was implemented for high performance,e.g.,photon flux,energy-resolving power,and focus spot size.RXES experiments show that the energy range extends from 150 to 1500 eV.The elastic peak measured near titanium absorption edge(@445 eV)indicates an energy resolution of the RXES spectrometer of 65 meV.The measured photon flux is 3×10^(12)photons/s at 244 eV at the RXES sample position for an SSRF electron energy of 3.5 GeV and a projected ring current as 300 mA.The spot size at the RXES sample position is 23μm in the horizontal direction and 7.9μm in the vertical direction,respectively.Moreover,the angular resolution of elastic REXS scatterometer reaches 0.005°through measurement of X-ray reflection from the single-crystal silicon wafers.A sample of the REXS scatterometer is vibrationally decoupled from its chamber and cooled using copper braids connected from an open cycle liquid helium cryo reservoir,whereas the minimum sample temperature is below 15 K.展开更多
This paper describes the design and performance of the tender energy spectroscopy beamline(BL16U1),a phase Ⅱ beamline,at the Shanghai Synchrotron Radiation Facility.The beamline,based on an in-vacuum undulator source...This paper describes the design and performance of the tender energy spectroscopy beamline(BL16U1),a phase Ⅱ beamline,at the Shanghai Synchrotron Radiation Facility.The beamline,based on an in-vacuum undulator source with 26 mm period,provides an operable energy range between 2.1 keV and 16 keV,covering the K-edges of P to Rb and L3-edges of Zr to Bi.The principal optical elements of the beamline are a toroidal mirror,a liquid nitrogen-cooled double-crystal monochromator,a high-harmonic-rejection mirror,and two pairs of Kirkpatrick–Baez(KB)mirrors.Three end-stations,including non-focusing,microprobe,and sub-microprobe types,are installed on the beamline.X-ray fluorescence(XRF)and X-ray absorption spectroscopy(XAS),including X-ray absorption near-edge structure(XANES)and extended X-ray absorption fine structure(EXAFS),are performed under vacuum or He atmosphere at the non-focusing end-station(with a beam spot size of∼670μm×710μm).Using two KB mirrors systems,micro-XRF(μXRF)mapping and micro-XANES(μXANES)studies can be performed with a spot size of approximately∼3.3μm×1.3μm at the microprobe end-station and with a smaller spot size of∼0.5μm×0.25μm at the sub-microprobe end-station.The non-focusing end-station was officially opened to users in January 2024.The microprobe and sub-microprobe end-stations will be opened to users in the near future.This paper presents the characteristics,short-term technical developments,and early experimental results of this new beamline.展开更多
Rotational computed laminography(CL)has broad application potential in three-dimensional imaging of plate-like objects because it only requires X-rays to pass through the tested object in the thickness direction durin...Rotational computed laminography(CL)has broad application potential in three-dimensional imaging of plate-like objects because it only requires X-rays to pass through the tested object in the thickness direction during the imaging process.In this study,a rectangular cross-section field-of-view rotational CL(RC-CL)is proposed for circuit board imaging.Compared to other rotational CL systems,the field of view is the largest and most suitable for rectangular circuit boards.Meanwhile,as the imaging geometry of RC-CL is significantly different from that of cone-beam CT,the Feldkamp-Davis-Kress(FDK)reconstruction algorithm cannot be used directly.However,transferring the projection data to fit into the CBCT geometry using two-dimensional interpolation introduces interpolation errors.Therefore,an FDK-type analytical reconstruction algorithm applicable to RC-CL was developed.The effectiveness of the method was validated through numerical experiments,and the influence of the tilt angle on the reconstruction results was analyzed.Finally,the RC-CL technique was applied to real defect detection research on circuit boards.展开更多
Small angle x-ray scattering(SAXS)is an advanced technique for characterizing the particle size distribution(PSD)of nanoparticles.However,the ill-posed nature of inverse problems in SAXS data analysis often reduces th...Small angle x-ray scattering(SAXS)is an advanced technique for characterizing the particle size distribution(PSD)of nanoparticles.However,the ill-posed nature of inverse problems in SAXS data analysis often reduces the accuracy of conventional methods.This article proposes a user-friendly software for PSD analysis,GranuSAS,which employs an algorithm that integrates truncated singular value decomposition(TSVD)with the Chahine method.This approach employs TSVD for data preprocessing,generating a set of initial solutions with noise suppression.A high-quality initial solution is subsequently selected via the L-curve method.This selected candidate solution is then iteratively refined by the Chahine algorithm,enforcing constraints such as non-negativity and improving physical interpretability.Most importantly,GranuSAS employs a parallel architecture that simultaneously yields inversion results from multiple shape models and,by evaluating the accuracy of each model's reconstructed scattering curve,offers a suggestion for model selection in material systems.To systematically validate the accuracy and efficiency of the software,verification was performed using both simulated and experimental datasets.The results demonstrate that the proposed software delivers both satisfactory accuracy and reliable computational efficiency.It provides an easy-to-use and reliable tool for researchers in materials science,helping them fully exploit the potential of SAXS in nanoparticle characterization.展开更多
Laser wakefield accelerators(LWFAs)offer acceleration gradients up to 1000 times higher than those of conventional radio-frequency accelerators,offering a pathway to significantly more compact and cost-effective accel...Laser wakefield accelerators(LWFAs)offer acceleration gradients up to 1000 times higher than those of conventional radio-frequency accelerators,offering a pathway to significantly more compact and cost-effective accelerator systems.This breakthrough opens up new possibilities for laboratory-scale light sources.All-optical inverse Compton scattering(AOCS)sources driven by LWFAs produce high-brightness,quasimonochromatic X rays with micrometer-scale source sizes,delivering the spatial coherence and resolution required for X-ray phase-contrast imaging(XPCI).These features position AOCS X-ray sources as promising tools for applications in biology,medicine,physics,and materials science.However,previous AOCS-based imaging studies have primarily focused on X-ray absorption imaging.In this work,we report successful experimental demonstrations of edge-enhanced in-line XPCI using energy-tunable,quasi-monochromatic AOCS X rays.With a spatial resolution of~20μm,our results clearly show the potential of high-resolution,AOCS-based XPCI applications.展开更多
Lead halide perovskites have emerged as promising scintillators for X-ray imaging owing to their high Xray absorption efficiency,excellent luminescence properties,and facile synthesis.However,their intrinsic ionic nat...Lead halide perovskites have emerged as promising scintillators for X-ray imaging owing to their high Xray absorption efficiency,excellent luminescence properties,and facile synthesis.However,their intrinsic ionic nature poses a fundamental challenge in simultaneously achieving high photoluminescence efficiency and environmental robustness.Here,we introduce a multilevel encapsulation strategy by sequentially coating CsPbBr_(3)quantum dots(QDs)with Cs_(4)PbBr_(6),SiO_(2),and polydimethylsiloxane(PDMS),thereby synergistically enhancing both optical performance and stability.Cs_(4)PbBr_(6)effectively passivates surface defects of CsPbBr_(3)QDs,while the SiO_(2)and PDMS layers serve as protective barriers against moisture,heat,and radiation.The resulting CsPbBr_(3)@Cs_(4)PbBr_(6)/SiO_(2)/PDMS flexible films exhibit a high photoluminescence quantum yield of 85%,outstanding mechanical flexibility,and remarkable durability under stretching,bending,and compressing.Moreover,the films retain excellent emission stability under elevated temperatures,prolonged X-ray irradiation,and extended water immersion.X-ray imaging evaluations further demonstrate a spatial resolution of 12 lp/mm,enabling distortion-free imaging of curved objects,while their superior water resistance allows for long-term underwater X-ray imaging.This work highlights the critical role of hierarchical encapsulation in balancing luminescence efficiency and environmental stability,offering a viable pathway toward practical high-performance flexible perovskite scintillators.展开更多
With the development of the semiconductor industry below the 7 nm scale,critical dimension small-angle X-ray scattering(CD-SAXS)has emerged as a powerful tool for quantitatively measuring nanoscale deviations.In this ...With the development of the semiconductor industry below the 7 nm scale,critical dimension small-angle X-ray scattering(CD-SAXS)has emerged as a powerful tool for quantitatively measuring nanoscale deviations.In this study,the effects of X-ray beam size and photon energy on the accuracy of critical dimension measurements were investigated.Critical dimensions measured using beams with different spot sizes showed different deviations from the expected values.Beam sizes that were either too large or too small did not improve confidence intervals.As the incident energy increased,the X-ray transmission rate increased,while the scattering cross section decreased,resulting in a gradual decrease in the signal-to-noise ratio of the diffraction peaks,which reduced the accuracy of the CD-SAXS measurements.An optimal accuracy was obtained at 12 keV with a smaller beam size.Using an effective trapezoid model,the results yielded an average pitch of 100.4±0.2 nm,width of 49.8±0.2 nm,height of 130.0±0.2 nm,and a sidewall angle below 1.1°±0.1°.These results provide crucial guidance for the future development of CD-SAXS laboratories and the construction of X-ray machines as well as robust support for research in related fields.展开更多
文摘A soft X-ray energy materials research beamline(BL20U2),a branch of energy materials beamline(E-line),has been constructed in the Shanghai Synchrotron Radiation Facility(SSRF)Phase-II project.It is now operational for soft X-ray resonant emission spectroscopy(RXES)and soft X-ray resonant elastic scattering(REXS)investigations.Optical optimization was implemented for high performance,e.g.,photon flux,energy-resolving power,and focus spot size.RXES experiments show that the energy range extends from 150 to 1500 eV.The elastic peak measured near titanium absorption edge(@445 eV)indicates an energy resolution of the RXES spectrometer of 65 meV.The measured photon flux is 3×10^(12)photons/s at 244 eV at the RXES sample position for an SSRF electron energy of 3.5 GeV and a projected ring current as 300 mA.The spot size at the RXES sample position is 23μm in the horizontal direction and 7.9μm in the vertical direction,respectively.Moreover,the angular resolution of elastic REXS scatterometer reaches 0.005°through measurement of X-ray reflection from the single-crystal silicon wafers.A sample of the REXS scatterometer is vibrationally decoupled from its chamber and cooled using copper braids connected from an open cycle liquid helium cryo reservoir,whereas the minimum sample temperature is below 15 K.
基金supported by the National Key R&D Program of China(No.2021YFA1601003)the financial support of the SSRF PhaseⅡproject.
文摘This paper describes the design and performance of the tender energy spectroscopy beamline(BL16U1),a phase Ⅱ beamline,at the Shanghai Synchrotron Radiation Facility.The beamline,based on an in-vacuum undulator source with 26 mm period,provides an operable energy range between 2.1 keV and 16 keV,covering the K-edges of P to Rb and L3-edges of Zr to Bi.The principal optical elements of the beamline are a toroidal mirror,a liquid nitrogen-cooled double-crystal monochromator,a high-harmonic-rejection mirror,and two pairs of Kirkpatrick–Baez(KB)mirrors.Three end-stations,including non-focusing,microprobe,and sub-microprobe types,are installed on the beamline.X-ray fluorescence(XRF)and X-ray absorption spectroscopy(XAS),including X-ray absorption near-edge structure(XANES)and extended X-ray absorption fine structure(EXAFS),are performed under vacuum or He atmosphere at the non-focusing end-station(with a beam spot size of∼670μm×710μm).Using two KB mirrors systems,micro-XRF(μXRF)mapping and micro-XANES(μXANES)studies can be performed with a spot size of approximately∼3.3μm×1.3μm at the microprobe end-station and with a smaller spot size of∼0.5μm×0.25μm at the sub-microprobe end-station.The non-focusing end-station was officially opened to users in January 2024.The microprobe and sub-microprobe end-stations will be opened to users in the near future.This paper presents the characteristics,short-term technical developments,and early experimental results of this new beamline.
基金supported by the National Key Research and Development Program of China(No.2022YFF0607802)。
文摘Rotational computed laminography(CL)has broad application potential in three-dimensional imaging of plate-like objects because it only requires X-rays to pass through the tested object in the thickness direction during the imaging process.In this study,a rectangular cross-section field-of-view rotational CL(RC-CL)is proposed for circuit board imaging.Compared to other rotational CL systems,the field of view is the largest and most suitable for rectangular circuit boards.Meanwhile,as the imaging geometry of RC-CL is significantly different from that of cone-beam CT,the Feldkamp-Davis-Kress(FDK)reconstruction algorithm cannot be used directly.However,transferring the projection data to fit into the CBCT geometry using two-dimensional interpolation introduces interpolation errors.Therefore,an FDK-type analytical reconstruction algorithm applicable to RC-CL was developed.The effectiveness of the method was validated through numerical experiments,and the influence of the tilt angle on the reconstruction results was analyzed.Finally,the RC-CL technique was applied to real defect detection research on circuit boards.
基金Project supported by the Project of the Anhui Provincial Natural Science Foundation(Grant No.2308085MA19)Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA0410401)+2 种基金the National Natural Science Foundation of China(Grant No.52202120)the National Key Research and Development Program of China(Grant No.2023YFA1609800)USTC Research Funds of the Double First-Class Initiative(Grant No.YD2310002013)。
文摘Small angle x-ray scattering(SAXS)is an advanced technique for characterizing the particle size distribution(PSD)of nanoparticles.However,the ill-posed nature of inverse problems in SAXS data analysis often reduces the accuracy of conventional methods.This article proposes a user-friendly software for PSD analysis,GranuSAS,which employs an algorithm that integrates truncated singular value decomposition(TSVD)with the Chahine method.This approach employs TSVD for data preprocessing,generating a set of initial solutions with noise suppression.A high-quality initial solution is subsequently selected via the L-curve method.This selected candidate solution is then iteratively refined by the Chahine algorithm,enforcing constraints such as non-negativity and improving physical interpretability.Most importantly,GranuSAS employs a parallel architecture that simultaneously yields inversion results from multiple shape models and,by evaluating the accuracy of each model's reconstructed scattering curve,offers a suggestion for model selection in material systems.To systematically validate the accuracy and efficiency of the software,verification was performed using both simulated and experimental datasets.The results demonstrate that the proposed software delivers both satisfactory accuracy and reliable computational efficiency.It provides an easy-to-use and reliable tool for researchers in materials science,helping them fully exploit the potential of SAXS in nanoparticle characterization.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0530000)the Discipline Construction Foundation of“Double World-class Project”.
文摘Laser wakefield accelerators(LWFAs)offer acceleration gradients up to 1000 times higher than those of conventional radio-frequency accelerators,offering a pathway to significantly more compact and cost-effective accelerator systems.This breakthrough opens up new possibilities for laboratory-scale light sources.All-optical inverse Compton scattering(AOCS)sources driven by LWFAs produce high-brightness,quasimonochromatic X rays with micrometer-scale source sizes,delivering the spatial coherence and resolution required for X-ray phase-contrast imaging(XPCI).These features position AOCS X-ray sources as promising tools for applications in biology,medicine,physics,and materials science.However,previous AOCS-based imaging studies have primarily focused on X-ray absorption imaging.In this work,we report successful experimental demonstrations of edge-enhanced in-line XPCI using energy-tunable,quasi-monochromatic AOCS X rays.With a spatial resolution of~20μm,our results clearly show the potential of high-resolution,AOCS-based XPCI applications.
基金supported by the National Natural Science Foundation of China(52250060,62274135,62288102,12504473)the China Postdoctoral Science Foundation(2025M773420,2024M764250)+1 种基金the Key Project of Ningbo Natural Science Foundation(20221JCGY01049)the Postdoctoral Fellowship Program of the China Postdoctoral Science Foundation(CPSF)(GZB20230975)。
文摘Lead halide perovskites have emerged as promising scintillators for X-ray imaging owing to their high Xray absorption efficiency,excellent luminescence properties,and facile synthesis.However,their intrinsic ionic nature poses a fundamental challenge in simultaneously achieving high photoluminescence efficiency and environmental robustness.Here,we introduce a multilevel encapsulation strategy by sequentially coating CsPbBr_(3)quantum dots(QDs)with Cs_(4)PbBr_(6),SiO_(2),and polydimethylsiloxane(PDMS),thereby synergistically enhancing both optical performance and stability.Cs_(4)PbBr_(6)effectively passivates surface defects of CsPbBr_(3)QDs,while the SiO_(2)and PDMS layers serve as protective barriers against moisture,heat,and radiation.The resulting CsPbBr_(3)@Cs_(4)PbBr_(6)/SiO_(2)/PDMS flexible films exhibit a high photoluminescence quantum yield of 85%,outstanding mechanical flexibility,and remarkable durability under stretching,bending,and compressing.Moreover,the films retain excellent emission stability under elevated temperatures,prolonged X-ray irradiation,and extended water immersion.X-ray imaging evaluations further demonstrate a spatial resolution of 12 lp/mm,enabling distortion-free imaging of curved objects,while their superior water resistance allows for long-term underwater X-ray imaging.This work highlights the critical role of hierarchical encapsulation in balancing luminescence efficiency and environmental stability,offering a viable pathway toward practical high-performance flexible perovskite scintillators.
基金supported by the National Natural Science Foundation of China(No.12175295)the National Key R&D Program of China(2021YFA1601000)the Shanghai Municipal Science and Technology Major Project。
文摘With the development of the semiconductor industry below the 7 nm scale,critical dimension small-angle X-ray scattering(CD-SAXS)has emerged as a powerful tool for quantitatively measuring nanoscale deviations.In this study,the effects of X-ray beam size and photon energy on the accuracy of critical dimension measurements were investigated.Critical dimensions measured using beams with different spot sizes showed different deviations from the expected values.Beam sizes that were either too large or too small did not improve confidence intervals.As the incident energy increased,the X-ray transmission rate increased,while the scattering cross section decreased,resulting in a gradual decrease in the signal-to-noise ratio of the diffraction peaks,which reduced the accuracy of the CD-SAXS measurements.An optimal accuracy was obtained at 12 keV with a smaller beam size.Using an effective trapezoid model,the results yielded an average pitch of 100.4±0.2 nm,width of 49.8±0.2 nm,height of 130.0±0.2 nm,and a sidewall angle below 1.1°±0.1°.These results provide crucial guidance for the future development of CD-SAXS laboratories and the construction of X-ray machines as well as robust support for research in related fields.
