Toward monochromated sub-nanometer UEM and femtosecond UED

doi:10.1038/s41598-020-73168-z

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	Toward monochromated sub-nanometer UEM and femtosecond UED
	Yang, Xi 1; Wan, Weishi2 ; Wu, Lijun 3; Smaluk, Victor 1; Shaftan, Timur 1; Zhu, Yimei 3
	2020-09-30
发表期刊	SCIENTIFIC REPORTS (IF:3.8[JCR-2023],4.3[5-Year])
ISSN	2045-2322
卷号	10 期号:1
DOI	10.1038/s41598-020-73168-z
摘要	A preliminary design of a mega-electron-volt (MeV) monochromator with 10(-5) energy spread for ultrafast electron diffraction (UED) and ultrafast electron microscopy (UEM) is presented. Such a narrow energy spread is advantageous in both the single shot mode, where the momentum resolution in diffraction is improved, and the accumulation mode, where shot-to-shot energy jitter is reduced. In the single-shot mode, we numerically optimized the monochromator efficiency up to 13% achieving 1.3 million electrons per pulse. In the accumulation mode, to mitigate the efficiency degradation caused by the shot-to-shot energy jitter, an optimized gun phase yields only a mild reduction of the single-shot efficiency, therefore the number of accumulated electrons nearly proportional to the repetition rate. Inspired by the recent work of Qi et al. (Phys Rev Lett 124:134803, 2020), a novel concept of applying reverse bending magnets to adjust the energy-dependent path length difference has been successfully realized in designing a MeV monochromator to achieve the minimum energy-dependent path length difference between cathode and sample. Thanks to the achromat design, the pulse length of the electron bunches and the energy-dependent timing jitter can be greatly reduced to the 10 fs level. The introduction of such a monochromator provides a major step forward, towards constructing a UEM with sub-nm resolution and a UED with ten-femtosecond temporal resolution. The one-to-one mapping between the electron beam parameter and the diffraction peak broadening enables a real-time nondestructive diagnosis of the beam energy spread and divergence. The tunable electric-magnetic monochromator allows the scanning of the electron beam energy with a 10(-5) precision, enabling online energy matching for the UEM, on-momentum flux maximizing for the UED and real-time energy measuring for energy-loss spectroscopy. A combination of the monochromator and a downstream chicane enables "two-color" double pulses with femtosecond duration and the tunable delay in the range of 10 to 160 fs, which can potentially provide an unprecedented femtosecond time resolution for time resolved UED.
收录类别	SCI ; SCIE
语种	英语
资助项目	Office of Basic Energy Sciences (BES), U.S. Department of Energy (DOE)[DE-SC0012704]
WOS研究方向	Science & Technology - Other Topics
WOS类目	Multidisciplinary Sciences
WOS记录号	WOS:000577213600013
出版者	NATURE RESEARCH
引用统计	正在获取...
文献类型	期刊论文
条目标识符	https://kms.shanghaitech.edu.cn/handle/2MSLDSTB/123520
专题	大科学中心物质科学与技术学院
通讯作者	Yang, Xi; Wan, Weishi
作者单位	1.Brookhaven Natl Lab, Natl Synchrotron Light Source 2, Upton, NY 11973 USA; 2.ShanghaiTech Univ, Sch Phys Sci & Technol, Shanghai, Peoples R China; 3.Brookhaven Natl Lab, Condensed Matter Phys & Mat Sci Div, Upton, NY 11973 USA
通讯作者单位	物质科学与技术学院
推荐引用方式 GB/T 7714	Yang, Xi,Wan, Weishi,Wu, Lijun,et al. Toward monochromated sub-nanometer UEM and femtosecond UED[J]. SCIENTIFIC REPORTS,2020,10(1).
APA	Yang, Xi,Wan, Weishi,Wu, Lijun,Smaluk, Victor,Shaftan, Timur,&Zhu, Yimei.(2020).Toward monochromated sub-nanometer UEM and femtosecond UED.SCIENTIFIC REPORTS,10(1).
MLA	Yang, Xi,et al."Toward monochromated sub-nanometer UEM and femtosecond UED".SCIENTIFIC REPORTS 10.1(2020).