A compact tunable quadrupole lens for brighter and sharper ultra-fast electron diffraction imaging

doi:10.1038/s41598-019-39208-z

	A compact tunable quadrupole lens for brighter and sharper ultra-fast electron diffraction imaging
	Yang, Xi 1; Yu, Lihua 1; Smaluk, Victor 1; Wang, Guimei 1; Hidaka, Yoshitreu 1; Shaftan, Timur 1; Doom, Lewis 1; Padrazo, Danny 1; Li, Junjie 1; Fedurin, Mikhail 1; Wan, Weishi2 ; Zhu, Yimei 1
	2019-03-26
发表期刊	SCIENTIFIC REPORTS
ISSN	2045-2322
卷号	9
发表状态	已发表
DOI	10.1038/s41598-019-39208-z
摘要	In this article, we report our proof-of-principle design and experimental commissioning of a broadly tunable and low-cost transverse focusing lens system for MeV-energy electron beams. The lens system based on electromagnetic (EM) quadrupoles has been built as a part of the existing instrument for ultrafast electron diffraction (UED) experiments at the Accelerator Test Facility II (ATF-II) at Brookhaven National Laboratory (BNL). We experimentally demonstrated the independent control of the size and divergence of the beam with the charge ranging from 1 to 13 pC. The charge density and divergence of the beam at the sample are the most important factors determining the quality of the Bragg-diffraction image (BDI). By applying the Robust Conjugate Directional Search (RCDS) algorithm for online optimization of the quadrupoles, the transverse beam size can be kept constant down to 75 mu m from 1 to 13 pC. The charge density is nearly two orders of magnitude higher than the previously achieved value using a conventional solenoid. Using the BDI method we were able to extract the divergence of the beam in real-time and apply it to the emittance measurement for the first time. Our results agree well with simulations and with the traditional quadrupole scan method. The real-time divergence measurement opens the possibility of online optimization of the beam divergence (<0.2 mrad) at the sample with the increased beam charge. This optimization is crucial for the future development of single-shot ultra-fast electron microscope (UEM). Finally, we demonstrated BDI with significant improvement, up to 3 times higher peak intensity and 2 times sharper Bragg-diffraction peaks at 13 pC. The charge is now limited by the laser power and increasing charge may improve the quality of BDI further. The capability we demonstrated here provides us with opportunities for new sciences using near-parallel, bright and ultrafast electron beams for single-shot imaging, to directly visualize the dynamics of defects and nanostructured materials, or even record molecular movie, which are impossible using present electron-beam technologies.
收录类别	SCI ; SCIE
语种	英语
资助项目	U.S. Department of Energy[DE-SC0012704]
WOS研究方向	Science & Technology - Other Topics
WOS类目	Multidisciplinary Sciences
WOS记录号	WOS:000462298600002
出版者	NATURE PUBLISHING GROUP
原始文献类型	Article
引用统计
文献类型	期刊论文
条目标识符	https://kms.shanghaitech.edu.cn/handle/2MSLDSTB/34183
专题	大科学中心_PI研究组_万唯实组大科学中心
通讯作者	Yang, Xi
作者单位	1.Brookhaven Natl Lab, Upton, NY 11973 USA 2.ShanghaiTech Univ, Shanghai, Peoples R China
推荐引用方式 GB/T 7714	Yang, Xi,Yu, Lihua,Smaluk, Victor,et al. A compact tunable quadrupole lens for brighter and sharper ultra-fast electron diffraction imaging[J]. SCIENTIFIC REPORTS,2019,9.
APA	Yang, Xi.,Yu, Lihua.,Smaluk, Victor.,Wang, Guimei.,Hidaka, Yoshitreu.,...&Zhu, Yimei.(2019).A compact tunable quadrupole lens for brighter and sharper ultra-fast electron diffraction imaging.SCIENTIFIC REPORTS,9.
MLA	Yang, Xi,et al."A compact tunable quadrupole lens for brighter and sharper ultra-fast electron diffraction imaging".SCIENTIFIC REPORTS 9(2019).