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Precession Electron Diffraction (PED) offers a number of advantages for crystal structure analysis and solving unknown structures using electron diffraction. The current article uses many-beam simulations of PED intensities, in combination…
If matter absorbs a photon of sufficient energy it emits an electron. The question of the duration of the emission process has intrigued scientists for decades. With the advent of attosecond metrology, experiments addressing such ultrashort…
We report an experimental technique to measure and manipulate the arrival-time and energy distributions of electrons emitted from a semiconductor electron pump, operated as both a single-electron source and a two-electron source. Using an…
Ultrashort, low-emittance electron pulses can be created at a high repetition rate by using a TM$_{110}$ deflection cavity to sweep a continuous beam across an aperture. These pulses can be used for time-resolved electron microscopy with…
To produce the intense, high-quality hadron beams required by future nuclear and high-energy physics experiments, synchrotrons need to overcome a most prominent intensity limitation i.e., space charge. This Letter characterizes the…
The electric field governing the dynamics of space charge produced by high intensity femtosecond laser pulses focused on a copper surface is investigated by time-resolved low-energy-electron-scattering. The pump-probe experiment has a…
The electric dipole moment of the electron (eEDM) can be measured with high precision using heavy polar molecules. In this paper, we report on a series of new techniques that have improved the statistical sensitivity of the YbF eEDM…
Ultrafast electron diffraction and phonon-diffuse scattering (UED(S)) experiments make use of photo-induced changes to electron scattering intensity across 2D detectors to report on a very wide range of dynamic structural phenomena in…
The diffraction patterns of crystalline materials with local order contain sharp Bragg reflections as well as highly structured diffuse scattering. The instrumental requirements, experimental parameters and data processing techniques for…
Field emission or dark current from RF electron guns is problematic for accelerators for several reasons, and can be more difficult to predict, measure and understand, compared to the main beam. The work presented here is a study of the…
Ultrafast-optical-pump -- structural-probe measurements, including ultrafast electron and x-ray scattering, provide direct experimental access to the fundamental timescales of atomic motion, and are thus foundational techniques for studying…
We present the design of a high repetition rate MeV energy ultrafast electron diffraction instrument based on a DC photoelectron gun and an SRF linac with multiple independently controlled accelerating and bunching cavities. The design is…
We analyze the dynamics of up to $10^5$ electrons resulting from illuminating a Xenon cluster with 9093 atoms with intense laser pulses of different length and peak intensity. Interesting details of electron motion are identified which can…
We present a nano-scale photoelectron source, optimized towards ultrashort pulse durations and well-suited for time-resolved diffraction experiments. A tungsten tip, mounted in a suppressor-extractor electrode configuration, allows the…
High quality electron beams, with high spatial and tempo- ral resolution, have an important use in electron diffraction experiments to probe and study the constituents of matter. A cold electron source is being developed based on elec- tron…
The Fraunhofer diffraction of quantum particles from materials with sharp electron-density edges or symmetric bond structures is ubiquitous. In contrast, diffraction from atoms with characteristic asymptotically-diffused electron…
We present the results of multi-objective genetic algorithm optimizations of a potential single shot ultra fast electron diffraction beamline utilizing a 225 kV dc gun with a novel cryocooled photocathode system and buncher cavity.…
The structural evolution of laser-excited systems of gold has previously been measured through ultrafast MeV electron diffraction. However, there has been a long-standing inability of atomistic simulations to provide a consistent picture of…
Determining the pulse duration of femtosecond electron bunches is challenging and often experimentally invasive. An effective method for measuring the duration based on the time-dependent variations in electron beam divergence induced by a…
The ability to resolve the dynamics of matter on its native temporal and spatial scales constitutes a key challenge and convergent theme across chemistry, biology, and materials science. The last couple of decades have witnessed ultrafast…