Cascading stages of seeded free electron lasers（FELs） is a promising way to produce fully coherent X-ray radiation. We study a new approach to produce coherent hard X-rays by cascading the recently proposed phasemer...Cascading stages of seeded free electron lasers（FELs） is a promising way to produce fully coherent X-ray radiation. We study a new approach to produce coherent hard X-rays by cascading the recently proposed phasemerging enhanced harmonic generation（PEHG） The scheme consists of one dogleg and two PEHG configurations,and may be one of the leading candidates for the extracted undulator branch in future X-ray FEL facilities. FEL physics studies show that such a scheme is feasible within the present technology and can provide high brightness Xray radiation pulses with narrow bandwidth and full coherence The radiated peak power at 1 ？A wavelength converted from an initial 200 nm seed laser is over 2 GW展开更多
The polarization switch of a free-electron laser （FEL） is of great importance to the user scientific community. In this paper, we investigate the generation of controllable polarization FEL from two well-known appro...The polarization switch of a free-electron laser （FEL） is of great importance to the user scientific community. In this paper, we investigate the generation of controllable polarization FEL from two well-known approaches for Dalian coherent light source, i.e., crossed planar undulator and elliptical permanent undulator. In order to perform a fair comparative study, a one-dimensional time-dependent FEL code has been developed, in which the imperfection effects of an elliptical permanent undulator are taken into account. Comprehensive simulation results indicate that the residual beam energy chirp and the intrinsic FEL gain may contribute to the degradation of the polarization performance for the crossed planar undulator. Tile elliptical permanent undulator is not very sensitive to the undulator errors and beam imperfections. Meanwhile, with proper configurations of the main planar undulators and additional elliptical pernmuent undulator section, circular polarized FEL with pulse energy exceeding 100 bt.J could be achieved at Dalian coherent light source.展开更多
基金supported by the National Key Research and Development Program of(No.2021YFA1500601 and No.2018YFA0208703)the National Natural Science Foundation of China(No.21973010 and No.21973092)+3 种基金the Instrument Developing Project of the Chinese Academy of Sciences(No.YZ201504)the CAS Projects for Young Scientists in Basic Research(No.YSBR-007)the Dalian Institute of Chemical Physics Innovation Foundation(DICP I202205)LiaoNing Revitalization Talents Program(No.XLYC1907032).
基金financially supported by the National Natural Science Foundation of China(No.22125303,No.92061203,and No.21688102)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB17000000)+2 种基金Dalian Institute of Chemical Physics(DICP DCLS201701)Chinese Academy of Sciences(No.GJJSTD20190002)K.C.Wong Education Foundation(No.GJTD-2018-06)。
基金supported by the National Natural Science Foundation of China (No.21327901,No.21673231,No.21673234,and No.21688102)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB17000000)K. C. Wong Education Foundation.
基金supported by the National Natural Science Foundation of China(No.21327901,No.21503222,No.21673231,and No.21688102)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB17000000)China Postdoctoral Science Foundation(No.2018M641718 and No.2018M641719)
基金Supported by the National Natural Science Foundation of China(21127902&11322550)Ten Thousand Talent Program
文摘Cascading stages of seeded free electron lasers（FELs） is a promising way to produce fully coherent X-ray radiation. We study a new approach to produce coherent hard X-rays by cascading the recently proposed phasemerging enhanced harmonic generation（PEHG） The scheme consists of one dogleg and two PEHG configurations,and may be one of the leading candidates for the extracted undulator branch in future X-ray FEL facilities. FEL physics studies show that such a scheme is feasible within the present technology and can provide high brightness Xray radiation pulses with narrow bandwidth and full coherence The radiated peak power at 1 ？A wavelength converted from an initial 200 nm seed laser is over 2 GW
基金Supported by Major State Basic Research Development Program of China(2011CB808300)Natural Science Foundation of China(11175240,11205234,11322550)
文摘The polarization switch of a free-electron laser （FEL） is of great importance to the user scientific community. In this paper, we investigate the generation of controllable polarization FEL from two well-known approaches for Dalian coherent light source, i.e., crossed planar undulator and elliptical permanent undulator. In order to perform a fair comparative study, a one-dimensional time-dependent FEL code has been developed, in which the imperfection effects of an elliptical permanent undulator are taken into account. Comprehensive simulation results indicate that the residual beam energy chirp and the intrinsic FEL gain may contribute to the degradation of the polarization performance for the crossed planar undulator. Tile elliptical permanent undulator is not very sensitive to the undulator errors and beam imperfections. Meanwhile, with proper configurations of the main planar undulators and additional elliptical pernmuent undulator section, circular polarized FEL with pulse energy exceeding 100 bt.J could be achieved at Dalian coherent light source.
