The Lobster Eye Imager for Astronomy(LEIA),a pathfinder of the Wide-field X-ray Telescope of the Einstein Probe mission,was successfully launched onboard the SATech-01 satellite of the Chinese Academy of Sciences on20...The Lobster Eye Imager for Astronomy(LEIA),a pathfinder of the Wide-field X-ray Telescope of the Einstein Probe mission,was successfully launched onboard the SATech-01 satellite of the Chinese Academy of Sciences on2022 July 27.In this paper,we introduce the design and on-ground test results of the LEIA instrument.Using stateof-the-art Micro-Pore Optics(MPO),a wide field of view of 346 square degrees(18.6°×18.6°)of the X-ray imager is realized.An optical assembly composed of 36 MPO chips is used to focus incident X-ray photons,and four large-format complementary metal-oxide semiconductor(CMOS)sensors,each of size 6 cm×6 cm,are used as the focal plane detectors.The instrument has an angular resolution of 4’-8’(in terms of FWHM)for the central focal spot of the point-spread function,and an effective area of 2-3 cm^(2) at 1 keV in essentially all the directions within the field of view.The detection passband is 0.5-4 keV in soft X-rays and the sensitivity is2-3×10^(-11) erg s^(-1) cm^(-2)(about 1 milliCrab)with a 1000 s observation.The total weight of LEIA is 56 kg and the power is 85 W.The satellite,with a design lifetime of 2 yr,operates in a Sun-synchronous orbit of 500 km with an orbital period of 95 minutes.LEIA is paving the way for future missions by verifying in flight the technologies of both novel focusing imaging optics and CMOS sensors for X-ray observation,and by optimizing the working setups of the instrumental parameters.In addition,LEIA is able to carry out scientific observations to find new transients and to monitor known sources in the soft X-ray band,albeit with limited useful observing time available.展开更多
Study on the influence of temperature on the mechanical properties across multiple scales has been a focus on the research of Hastelloy-X(HX)alloys for the application in high-temperature structure com-ponents.In this...Study on the influence of temperature on the mechanical properties across multiple scales has been a focus on the research of Hastelloy-X(HX)alloys for the application in high-temperature structure com-ponents.In this work,Molecular Dynamics(MD)and Crystal Plasticity(CP)are put together to solve it from atomic scale to mesoscopic scale.MD research indicates that the deformation of HX alloy occurs in two stages at temperature below 300 K:initially,as stacking fault deforms,stacking fault can trans-form into twinning with increasing strain.When the temperature exceeds 300 K,deformation primarily forms a stacking fault.The twinning deformation path transforms from intrinsic stacking fault to extrin-sic stacking fault and then to twinning.A mesoscopic-scale CP model was developed using atomic-scale deformation mechanisms to bridge the gap between deformation mechanisms and experimental results.The CP results indicate a functional relationship between the strength of HX alloy and temperature.This relationship appears insensitive to crystal texture and grain shape.Incorporating grain morphology and texture into the model significantly impacts the strength response of calculating HX alloy.After the ten-sile deformation of HX alloy at 300 and 1173 K,the atomic scale deformation results characterized by transmission electron microscopy are aligned with the MD simulation results.The relationship between strength and temperature predicted by CP results has also been validated.A thorough investigation into the deformation behavior of HX alloys across different scales,employing MD and CP models,introduces a novel approach for predicting the mechanical properties of superalloys.展开更多
基金supported by the Einstein Probe project,a mission in the Strategic Priority Program on Space Science of CAS(grant Nos.XDA15310000,XDA15052100)in part been supported by the European Union’s Horizon 2020 Program under the AHEAD2020 project(grant No.871158).
文摘The Lobster Eye Imager for Astronomy(LEIA),a pathfinder of the Wide-field X-ray Telescope of the Einstein Probe mission,was successfully launched onboard the SATech-01 satellite of the Chinese Academy of Sciences on2022 July 27.In this paper,we introduce the design and on-ground test results of the LEIA instrument.Using stateof-the-art Micro-Pore Optics(MPO),a wide field of view of 346 square degrees(18.6°×18.6°)of the X-ray imager is realized.An optical assembly composed of 36 MPO chips is used to focus incident X-ray photons,and four large-format complementary metal-oxide semiconductor(CMOS)sensors,each of size 6 cm×6 cm,are used as the focal plane detectors.The instrument has an angular resolution of 4’-8’(in terms of FWHM)for the central focal spot of the point-spread function,and an effective area of 2-3 cm^(2) at 1 keV in essentially all the directions within the field of view.The detection passband is 0.5-4 keV in soft X-rays and the sensitivity is2-3×10^(-11) erg s^(-1) cm^(-2)(about 1 milliCrab)with a 1000 s observation.The total weight of LEIA is 56 kg and the power is 85 W.The satellite,with a design lifetime of 2 yr,operates in a Sun-synchronous orbit of 500 km with an orbital period of 95 minutes.LEIA is paving the way for future missions by verifying in flight the technologies of both novel focusing imaging optics and CMOS sensors for X-ray observation,and by optimizing the working setups of the instrumental parameters.In addition,LEIA is able to carry out scientific observations to find new transients and to monitor known sources in the soft X-ray band,albeit with limited useful observing time available.
基金the financial support from the National Natural Science Foundation of China(Grant Nos.52175307,52105330,and 52205348)the Taishan Scholars Founda-tion of Shandong Province(No.tsqn201812128)the Shandong Natural Science Foundation(Grant No.ZR2023JQ021).
文摘Study on the influence of temperature on the mechanical properties across multiple scales has been a focus on the research of Hastelloy-X(HX)alloys for the application in high-temperature structure com-ponents.In this work,Molecular Dynamics(MD)and Crystal Plasticity(CP)are put together to solve it from atomic scale to mesoscopic scale.MD research indicates that the deformation of HX alloy occurs in two stages at temperature below 300 K:initially,as stacking fault deforms,stacking fault can trans-form into twinning with increasing strain.When the temperature exceeds 300 K,deformation primarily forms a stacking fault.The twinning deformation path transforms from intrinsic stacking fault to extrin-sic stacking fault and then to twinning.A mesoscopic-scale CP model was developed using atomic-scale deformation mechanisms to bridge the gap between deformation mechanisms and experimental results.The CP results indicate a functional relationship between the strength of HX alloy and temperature.This relationship appears insensitive to crystal texture and grain shape.Incorporating grain morphology and texture into the model significantly impacts the strength response of calculating HX alloy.After the ten-sile deformation of HX alloy at 300 and 1173 K,the atomic scale deformation results characterized by transmission electron microscopy are aligned with the MD simulation results.The relationship between strength and temperature predicted by CP results has also been validated.A thorough investigation into the deformation behavior of HX alloys across different scales,employing MD and CP models,introduces a novel approach for predicting the mechanical properties of superalloys.
