P Denham, Y Yang, V Guo, A Fisher, X Shen, T Xu, R J England, R K Li, P Musumeci
{"title":"相机长度可调的高能电子衍射仪。","authors":"P Denham, Y Yang, V Guo, A Fisher, X Shen, T Xu, R J England, R K Li, P Musumeci","doi":"10.1063/4.0000240","DOIUrl":null,"url":null,"abstract":"<p><p>Ultrafast electron diffraction (UED) stands as a powerful technique for real-time observation of structural dynamics at the atomic level. In recent years, the use of MeV electrons from radio frequency guns has been widely adopted to take advantage of the relativistic suppression of the space charge effects that otherwise limit the temporal resolution of the technique. Nevertheless, there is not a clear choice for the optimal energy for a UED instrument. Scaling to beam energies higher than a few MeV does pose significant technical challenges, mainly related to the inherent increase in diffraction camera length associated with the smaller Bragg angles. In this study, we report a solution by using a compact post-sample magnetic optical system to magnify the diffraction pattern from a crystal Au sample illuminated by an 8.2 MeV electron beam. Our method employs, as one of the lenses of the optical system, a triplet of compact, high field gradients (>500 T/m), small-gap (3.5 mm) Halbach permanent magnet quadrupoles. Shifting the relative position of the quadrupoles, we demonstrate tuning the magnification by more than a factor of two, a 6× improvement in camera length, and reciprocal space resolution better than 0.1 Å<sup>-1</sup> in agreement with beam transport simulations.</p>","PeriodicalId":48683,"journal":{"name":"Structural Dynamics-Us","volume":null,"pages":null},"PeriodicalIF":2.3000,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10965247/pdf/","citationCount":"0","resultStr":"{\"title\":\"High energy electron diffraction instrument with tunable camera length.\",\"authors\":\"P Denham, Y Yang, V Guo, A Fisher, X Shen, T Xu, R J England, R K Li, P Musumeci\",\"doi\":\"10.1063/4.0000240\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Ultrafast electron diffraction (UED) stands as a powerful technique for real-time observation of structural dynamics at the atomic level. In recent years, the use of MeV electrons from radio frequency guns has been widely adopted to take advantage of the relativistic suppression of the space charge effects that otherwise limit the temporal resolution of the technique. Nevertheless, there is not a clear choice for the optimal energy for a UED instrument. Scaling to beam energies higher than a few MeV does pose significant technical challenges, mainly related to the inherent increase in diffraction camera length associated with the smaller Bragg angles. In this study, we report a solution by using a compact post-sample magnetic optical system to magnify the diffraction pattern from a crystal Au sample illuminated by an 8.2 MeV electron beam. Our method employs, as one of the lenses of the optical system, a triplet of compact, high field gradients (>500 T/m), small-gap (3.5 mm) Halbach permanent magnet quadrupoles. Shifting the relative position of the quadrupoles, we demonstrate tuning the magnification by more than a factor of two, a 6× improvement in camera length, and reciprocal space resolution better than 0.1 Å<sup>-1</sup> in agreement with beam transport simulations.</p>\",\"PeriodicalId\":48683,\"journal\":{\"name\":\"Structural Dynamics-Us\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.3000,\"publicationDate\":\"2024-03-25\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10965247/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Structural Dynamics-Us\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.1063/4.0000240\",\"RegionNum\":2,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2024/3/1 0:00:00\",\"PubModel\":\"eCollection\",\"JCR\":\"Q3\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Structural Dynamics-Us","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1063/4.0000240","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/3/1 0:00:00","PubModel":"eCollection","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
High energy electron diffraction instrument with tunable camera length.
Ultrafast electron diffraction (UED) stands as a powerful technique for real-time observation of structural dynamics at the atomic level. In recent years, the use of MeV electrons from radio frequency guns has been widely adopted to take advantage of the relativistic suppression of the space charge effects that otherwise limit the temporal resolution of the technique. Nevertheless, there is not a clear choice for the optimal energy for a UED instrument. Scaling to beam energies higher than a few MeV does pose significant technical challenges, mainly related to the inherent increase in diffraction camera length associated with the smaller Bragg angles. In this study, we report a solution by using a compact post-sample magnetic optical system to magnify the diffraction pattern from a crystal Au sample illuminated by an 8.2 MeV electron beam. Our method employs, as one of the lenses of the optical system, a triplet of compact, high field gradients (>500 T/m), small-gap (3.5 mm) Halbach permanent magnet quadrupoles. Shifting the relative position of the quadrupoles, we demonstrate tuning the magnification by more than a factor of two, a 6× improvement in camera length, and reciprocal space resolution better than 0.1 Å-1 in agreement with beam transport simulations.
Structural Dynamics-UsCHEMISTRY, PHYSICALPHYSICS, ATOMIC, MOLECU-PHYSICS, ATOMIC, MOLECULAR & CHEMICAL
CiteScore
5.50
自引率
3.60%
发文量
24
审稿时长
16 weeks
期刊介绍:
Structural Dynamics focuses on the recent developments in experimental and theoretical methods and techniques that allow a visualization of the electronic and geometric structural changes in real time of chemical, biological, and condensed-matter systems. The community of scientists and engineers working on structural dynamics in such diverse systems often use similar instrumentation and methods.
The journal welcomes articles dealing with fundamental problems of electronic and structural dynamics that are tackled by new methods, such as:
Time-resolved X-ray and electron diffraction and scattering,
Coherent diffractive imaging,
Time-resolved X-ray spectroscopies (absorption, emission, resonant inelastic scattering, etc.),
Time-resolved electron energy loss spectroscopy (EELS) and electron microscopy,
Time-resolved photoelectron spectroscopies (UPS, XPS, ARPES, etc.),
Multidimensional spectroscopies in the infrared, the visible and the ultraviolet,
Nonlinear spectroscopies in the VUV, the soft and the hard X-ray domains,
Theory and computational methods and algorithms for the analysis and description of structuraldynamics and their associated experimental signals.
These new methods are enabled by new instrumentation, such as:
X-ray free electron lasers, which provide flux, coherence, and time resolution,
New sources of ultrashort electron pulses,
New sources of ultrashort vacuum ultraviolet (VUV) to hard X-ray pulses, such as high-harmonic generation (HHG) sources or plasma-based sources,
New sources of ultrashort infrared and terahertz (THz) radiation,
New detectors for X-rays and electrons,
New sample handling and delivery schemes,
New computational capabilities.