Purpose Background removal is an important issue in data reduction for the follow-up X-ray telescope(FXT)onboard the Einstein Probe(EP),particularly for the particle-induced background.They appear in various charge pa...Purpose Background removal is an important issue in data reduction for the follow-up X-ray telescope(FXT)onboard the Einstein Probe(EP),particularly for the particle-induced background.They appear in various charge patterns in the focal plane PN-CCD,such as straight tracks,isolated showers and broad rectangular swathes.Methods We use the data obtained with the FXT mirror assembly covered,which are due to particle-induced background,to study the methods for rejecting such background.Results The particle-induced background in the FXT comprises background directly caused by particles,as well as instrument events that are also due to particles.A new rejection method,which involves cluster identification,and threshold veto for number of hits in rows and columns,is applied to remove the particle-induced background.The remaining background can be eliminated by the event reconstruction algorithm and event veto in subsequent FXT data reduction.Conclusion It is shown that their methods can achieve a background rejection efficiency of>99.8%.Additionally,there has been a notable decrease in the number of spikes in the light curves of the FXT.Furthermore,we found the instrument background is attributed to a combination of particles and CAMEX electronics.展开更多
This paper gives the directivity Function of a sectoral multi-element cylinder array, analyze its phase factor, explain in detail the sidelobe rejection by selecting the number of elements , baffling and amplitude wei...This paper gives the directivity Function of a sectoral multi-element cylinder array, analyze its phase factor, explain in detail the sidelobe rejection by selecting the number of elements , baffling and amplitude weighting. They are particularly useful for directional tracking of acoustical signal and target locating .展开更多
In this paper we present a method to generate independent samples for a general random variable,either continuous or discrete.The algorithm is an extension of the Acceptance-Rejectionmethod,and it is particularly usef...In this paper we present a method to generate independent samples for a general random variable,either continuous or discrete.The algorithm is an extension of the Acceptance-Rejectionmethod,and it is particularly useful for kinetic simulation in which the rates are fluctuating in time and have singular limits,as occurs for exam-ple in simulation of recombination interactions in a plasma.Although it depends on some additional requirements,the new method is easy to implement and rejects less samples than the Acceptance-Rejection method.展开更多
基金supported by the Einstein-Probe(EP)Program which is funded by the Strategic Priority Research Program of the Chinese Academy of Sciences Grant No.XDA15310000the National Natural Science Foundation of China under grant No.U1938102.
文摘Purpose Background removal is an important issue in data reduction for the follow-up X-ray telescope(FXT)onboard the Einstein Probe(EP),particularly for the particle-induced background.They appear in various charge patterns in the focal plane PN-CCD,such as straight tracks,isolated showers and broad rectangular swathes.Methods We use the data obtained with the FXT mirror assembly covered,which are due to particle-induced background,to study the methods for rejecting such background.Results The particle-induced background in the FXT comprises background directly caused by particles,as well as instrument events that are also due to particles.A new rejection method,which involves cluster identification,and threshold veto for number of hits in rows and columns,is applied to remove the particle-induced background.The remaining background can be eliminated by the event reconstruction algorithm and event veto in subsequent FXT data reduction.Conclusion It is shown that their methods can achieve a background rejection efficiency of>99.8%.Additionally,there has been a notable decrease in the number of spikes in the light curves of the FXT.Furthermore,we found the instrument background is attributed to a combination of particles and CAMEX electronics.
文摘This paper gives the directivity Function of a sectoral multi-element cylinder array, analyze its phase factor, explain in detail the sidelobe rejection by selecting the number of elements , baffling and amplitude weighting. They are particularly useful for directional tracking of acoustical signal and target locating .
文摘In this paper we present a method to generate independent samples for a general random variable,either continuous or discrete.The algorithm is an extension of the Acceptance-Rejectionmethod,and it is particularly useful for kinetic simulation in which the rates are fluctuating in time and have singular limits,as occurs for exam-ple in simulation of recombination interactions in a plasma.Although it depends on some additional requirements,the new method is easy to implement and rejects less samples than the Acceptance-Rejection method.
