Femtosecond Electron Guns for Ultrafast Electron Diffraction*
نویسندگان
چکیده
The photocathode radio-frequency (RF) gun is a powerful electron source to generate a high-brightness femtosecond electron beam with energies of 1~3 MeV. The RF gun based relativistic ultrafast electron diffraction (UED) is a promising new technique that has the potential to probe directly structural changes at the atomic scale with sub-100 fs temporal resolution. In this paper, we analyze the requirements and limitations of the beam parameters used in this technique. The characterization of the performance of femtosecond RF guns, and the experimental instruments of the RF gun based relativistic UED are reviewed. Finally, some demonstrations of relativistic UED measurements are reported.
منابع مشابه
Femtosecond Electron Bunch Generation Using Photocathode Rf Gun
A femtosecond electron bunch is essential for the observation of ultrafast phenomena. In order to improve the time resolution of pulse radiolysis and ultrafast electron diffraction (UED), that involve the use of an ultrashort electron bunch and ultrashort light, a femtosecond photocathode RF gun was investigated experimentally. The bunch length due to space-charge and RF effects in the gun was ...
متن کاملToward a terahertz-driven electron gun
Femtosecond electron bunches with keV energies and eV energy spread are needed by condensed matter physicists to resolve state transitions in carbon nanotubes, molecular structures, organic salts, and charge density wave materials. These semirelativistic electron sources are not only of interest for ultrafast electron diffraction, but also for electron energy-loss spectroscopy and as a seed for...
متن کاملPump-Probe and Time-Resolved Electron Microscopy and Big Data Analysis of Electron-Lattice Dynamics in Strongly Correlated Electron Systems
The recent development of ultrafast imaging and diffraction opened a new frontier for studying structural dynamics at nanoscales. It has become one of the key directions for future electron microscopy. Ultrafast electron microscopy combines the superior spatial resolution of conventional electron microscope with short electron pulses enabling the detection of electronic and atomic motion on the...
متن کاملIn-Situ Lorentz Microscopy with Femtosecond Optical Illumination
Ultrafast electron microscopy as a laser-pump/ electron-probe technique allows for the investigation of structural and electronic dynamics occurring at sub-picosecond timescales and nanometer length-scales [1,2]. However, current implementations necessitate compromises in electron source brightness compared to conventional electron microscopy techniques. Building on similar concepts in ultrafas...
متن کاملHigh-coherence picosecond electron bunches from cold atoms.
Ultrafast electron diffraction enables the study of molecular structural dynamics with atomic resolution at subpicosecond timescales, with applications in solid-state physics and rational drug design. Progress with ultrafast electron diffraction has been constrained by the limited transverse coherence of high-current electron sources. Photoionization of laser-cooled atoms can produce electrons ...
متن کامل