A ray tracing method is introduced for helping adjustment and spectra analysis of the grazing incidence flat-field imaging soft X-ray spectrometer. For a single point source, the spectra images obtained by separate co...A ray tracing method is introduced for helping adjustment and spectra analysis of the grazing incidence flat-field imaging soft X-ray spectrometer. For a single point source, the spectra images obtained by separate components, the toroidal mirror, and the grazing incidence flat-field concave grating with varied line spaces are given respectively. The calculated spectral images of the single point source by the spectrometer are also given for comparison with measurements with different experimental alignments.展开更多
Flat-field reflects the non-uniformity of the photometric response at the focal plane of an instrument,which uses digital image sensors,such as Charge Coupled Device(CCD)and Complementary Metal-Oxide-Semiconductor(CMO...Flat-field reflects the non-uniformity of the photometric response at the focal plane of an instrument,which uses digital image sensors,such as Charge Coupled Device(CCD)and Complementary Metal-Oxide-Semiconductor(CMOS).This non-uniformity must be corrected before being used for scientific research.In this paper,we assess various candidate methods via simulation using available data so as to figure the in-flight flat-field calibration methodology for the Lyman-alpha Solar Telescope(LST).LST is one of the payloads for the Advanced Space-based Solar Observatory(ASO-S)mission and consists of three instruments:a White-light Solar Telescope(WST),a Solar Disk Imager(SDI)and a dual-waveband Solar Corona Imager(SCI).In our simulations,data fromthe Helioseismic andMagnetic Imager(HMI)and Atmospheric Imaging Assembly(AIA)onboard the Solar Dynamics Observatory(SDO)mission are used.Our results show that the normal KLL method is appropriate for in-flight flat-field calibration of WST and implementing a transmissive diffuser is applicable for SCI.For the in-flight flat-field calibration of SDI,we recommend the KLL method with off-pointing images with defocused resolution of around 18′′,and use the local correlation tracking(LCT)algorithm instead of limb-fitting to determine the relative displacements between different images.展开更多
For reducing both extreme ultraviolet attosecond pulses energy loss in the focusing reflection process and measurement error caused by pulse focusing aberration, as well as improving the operability of pulse spectrosc...For reducing both extreme ultraviolet attosecond pulses energy loss in the focusing reflection process and measurement error caused by pulse focusing aberration, as well as improving the operability of pulse spectroscopy monitoring, a combined focusing and flat-field spectrometer analysis system for attosecond pulse is proposed and designed through step-by-step performance optimization. The focusing and spectrum-analyzing components are gold- coated grazing incidence to roidal mirror and grazing incidence concave focusing grating, respectively. The characteristic parameters of the system are given in details. The system proposed can find application in research platform of attosecond spectroscopy using high energy short attosecond pulse as basic probe tool.展开更多
Wide-field photobleaching imprinting microscopy(PIM)can improve fluorescence image contrast by cleverly exploiting the fluorophores’photobleaching properties.However,as conventional wide-field PIM commonly adopts Gau...Wide-field photobleaching imprinting microscopy(PIM)can improve fluorescence image contrast by cleverly exploiting the fluorophores’photobleaching properties.However,as conventional wide-field PIM commonly adopts Gaussian illumination with a nonuniform lateral fluence distribution,the field-of-view(FOV)and sampling density are largely reduced.In addition,the slow axial fluence gradient of Gaussian illumination limits the signal-to-background ratio(SBR)improvement and optical sectioning capability of PIM.Here,we present flat-field photobleaching imprinting microscopy(ffPIM)with a uniform lateral excitation fluence and sharp axial intensity gradient at the focal plane.ffPIM demonstrates low background,large FOV,and thin optical section.More importantly,compared to either conventional wide-field PIM or light-sheet microscopy,ffPIM shows much better balance for FOV,sampling density,SBR,and optical sectioning capability.The performance of ffPIM is characterized by simulation and resolving multiple cellular structures.Finally,ffPIM can be easily implemented to a standard commercial wide-field microscope and,thereby,allow general laboratories to benefit from this technique.展开更多
本文针对激光粉末床熔融(Laser Powder Bed Fusion,LPBF)技术的在线监测手段存在实时数据量大、设备改动量大、成本较高等问题,创新性地提出了一种面向LPBF技术的在线监测新方法。采用CMOS相机以长时间曝光的方式不间断采集激光运动轨...本文针对激光粉末床熔融(Laser Powder Bed Fusion,LPBF)技术的在线监测手段存在实时数据量大、设备改动量大、成本较高等问题,创新性地提出了一种面向LPBF技术的在线监测新方法。采用CMOS相机以长时间曝光的方式不间断采集激光运动轨迹图像,并将图像进行叠加获取灰度图像,该图像表示零件成型过程中每一层的热辐射分布。针对相机传感器各像素点响应不均匀的问题,提出了运用平场校正的方法处理图像提升图像的采集精度;针对相机安装位置导致的径向畸变问题,提出了基于亚像素提取法和黑白棋盘格的透视变换方法校正图像畸变。实验表明,本文设计的激光粉末床熔融光学断层扫描监测系统对工艺参数的变化敏感,能够实时获取零件成型过程中热辐射的分布与变化,可用于支持LPBF技术的工艺研发与缺陷监测。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11221002,11274152,and 11074297)
文摘A ray tracing method is introduced for helping adjustment and spectra analysis of the grazing incidence flat-field imaging soft X-ray spectrometer. For a single point source, the spectra images obtained by separate components, the toroidal mirror, and the grazing incidence flat-field concave grating with varied line spaces are given respectively. The calculated spectral images of the single point source by the spectrometer are also given for comparison with measurements with different experimental alignments.
基金This work is supported by the National Natural Science Foundation of China(Grant Nos.U1731241,11503089 and 11973012)by the CAS Strategic Pioneer Program on Space Science(Grant Nos.XDA15052200,XDA15320103 and XDA15320301).
文摘Flat-field reflects the non-uniformity of the photometric response at the focal plane of an instrument,which uses digital image sensors,such as Charge Coupled Device(CCD)and Complementary Metal-Oxide-Semiconductor(CMOS).This non-uniformity must be corrected before being used for scientific research.In this paper,we assess various candidate methods via simulation using available data so as to figure the in-flight flat-field calibration methodology for the Lyman-alpha Solar Telescope(LST).LST is one of the payloads for the Advanced Space-based Solar Observatory(ASO-S)mission and consists of three instruments:a White-light Solar Telescope(WST),a Solar Disk Imager(SDI)and a dual-waveband Solar Corona Imager(SCI).In our simulations,data fromthe Helioseismic andMagnetic Imager(HMI)and Atmospheric Imaging Assembly(AIA)onboard the Solar Dynamics Observatory(SDO)mission are used.Our results show that the normal KLL method is appropriate for in-flight flat-field calibration of WST and implementing a transmissive diffuser is applicable for SCI.For the in-flight flat-field calibration of SDI,we recommend the KLL method with off-pointing images with defocused resolution of around 18′′,and use the local correlation tracking(LCT)algorithm instead of limb-fitting to determine the relative displacements between different images.
文摘For reducing both extreme ultraviolet attosecond pulses energy loss in the focusing reflection process and measurement error caused by pulse focusing aberration, as well as improving the operability of pulse spectroscopy monitoring, a combined focusing and flat-field spectrometer analysis system for attosecond pulse is proposed and designed through step-by-step performance optimization. The focusing and spectrum-analyzing components are gold- coated grazing incidence to roidal mirror and grazing incidence concave focusing grating, respectively. The characteristic parameters of the system are given in details. The system proposed can find application in research platform of attosecond spectroscopy using high energy short attosecond pulse as basic probe tool.
基金supported by grants from the National Key R&D Program of China Nos.2021YFF0700304 and 2022YFA3401100 and the National Science Foundation of China 22127804.
文摘Wide-field photobleaching imprinting microscopy(PIM)can improve fluorescence image contrast by cleverly exploiting the fluorophores’photobleaching properties.However,as conventional wide-field PIM commonly adopts Gaussian illumination with a nonuniform lateral fluence distribution,the field-of-view(FOV)and sampling density are largely reduced.In addition,the slow axial fluence gradient of Gaussian illumination limits the signal-to-background ratio(SBR)improvement and optical sectioning capability of PIM.Here,we present flat-field photobleaching imprinting microscopy(ffPIM)with a uniform lateral excitation fluence and sharp axial intensity gradient at the focal plane.ffPIM demonstrates low background,large FOV,and thin optical section.More importantly,compared to either conventional wide-field PIM or light-sheet microscopy,ffPIM shows much better balance for FOV,sampling density,SBR,and optical sectioning capability.The performance of ffPIM is characterized by simulation and resolving multiple cellular structures.Finally,ffPIM can be easily implemented to a standard commercial wide-field microscope and,thereby,allow general laboratories to benefit from this technique.
文摘本文针对激光粉末床熔融(Laser Powder Bed Fusion,LPBF)技术的在线监测手段存在实时数据量大、设备改动量大、成本较高等问题,创新性地提出了一种面向LPBF技术的在线监测新方法。采用CMOS相机以长时间曝光的方式不间断采集激光运动轨迹图像,并将图像进行叠加获取灰度图像,该图像表示零件成型过程中每一层的热辐射分布。针对相机传感器各像素点响应不均匀的问题,提出了运用平场校正的方法处理图像提升图像的采集精度;针对相机安装位置导致的径向畸变问题,提出了基于亚像素提取法和黑白棋盘格的透视变换方法校正图像畸变。实验表明,本文设计的激光粉末床熔融光学断层扫描监测系统对工艺参数的变化敏感,能够实时获取零件成型过程中热辐射的分布与变化,可用于支持LPBF技术的工艺研发与缺陷监测。
