Flat or transversely asymmetric beams create transversely asymmetric wakefields. These wakefields are characterized by the creation of an elliptical cavity created by the evacuated plasma electrons and remnant ions. The potential inside these elliptical cavities is quadratic and yields transverse electric fields that are linear. Particle beams inside the blowout cavity can be matched to these...
RUEDI is a proposed Relativistic Ultrafast Electron Diffraction and Imaging facility for the UK. It will deliver single-shot time-resolved imaging with MeV electrons, as well as ultrafast electron diffraction at 10 fs timescales. The few-MeV-scale imaging and microscopy line aims to deliver high charge (up to 10^8 electrons), ultra-low emittance electron bunches to a 10µm sample with minimal...
RUEDI is a proposed facility for ultrafast electron microscopy (UEM) and ultrafast electron diffraction (UED) which is currently being designed and would be built in the UK. It will have two beamlines, one for microscopy and one for diffraction, which share a common electron gun. The diffraction beamline will operate with a kinetic energy of 4 MeV meaning that both space charge and ballistic...
The EuPRAXIA@SPARC_LAB RF injector provides high brightness electron beams accelerated and longitudinally manipulated in the velocity bunching regime (VB). The RF injector consists of a SPARC_LAB like S-band RF Gun (2.856 GHz) followed by four S-band TW accelerating structures with an overall length of 12.3 m. The RF injector works with the so called comb configuration, foresees a 30pC witness...
Betatron radiation spectroscopy is a valuable diagnostic technique for studying the interaction between a beam and a plasma in plasma wakefield acceleration (PWFA) experiments. In this project, we investigate the effects of beam perturbations on the betatron radiation. We analyze how perturbations can result in hosing, a transverse instability that can degrade the quality of the beam. We also...
We present the first analytic theoretical model describing the chromatic transverse dynamics of an electron beam in a nonlinear plasma-based accelerator that can account for the evolution of the projected, longitudinal sliced, and energy sliced emittance. Beginning with a description of single particle motion, the evolution of the beam moments and centroid position for each slice is...
We present measurements of the slice energy spread of the electron beam using two methods. The first and more standard way consists in measuring the slice beam size of the electrons in a dispersive location. The second method is based on the optical klystron mechanism, where the radiation produced in undulator modules is enhanced with magnetic chicanes between the modules. In this approach,...
Measuring the fermion statistics of free electrons has been a considerable experimental challenge of fundamental interest for many years. The attempts up to now, such as by Tonomura, have remained inconclusive because of the limited temporal resolution of the available detectors. The fermion statistics experimentally show up as electron anti-bunching - i.e., as a changed coincidence rate on a...
Challenges for future accelerators include characterization of high current beams and the need for continual drift correction while delivering beams with non-trivial phase space correlations. Concomitantly, there is potential for Artificial Intelligence/Machine Learning to improve beam quality, increase delivery time to users and enable exotic beam configurations. Non-invasive diagnostics...
Particle driven plasma wakefield acceleration (PWFA) exploits the intense wakefields excited in a plasma by a high brightness driver beam in order to accelerate a trailing, properly delayed witness beam. Moreover, multi-pulse driver beams with suitable spacing resonantly excite the plasma which enhances the amplitude of the accelerating field. However, before the injection into the plasma...
Plasma photocathode injection in plasma wakefield acceleration (PWFA) has the potential to produce ultrahigh brightness beams with normalized emittance down to 10s of nm-rad and kA peak currents. Electron beams in PWFA may develop a large energy chirp due to the high accelerating gradient, which can be detrimental to beam quality preservation and prevent use in demanding applications such as...
The SEALab accelerator test facility is currently commissioning the superconducting radio-frequency photoelectron injector (SRF photoinjector), which has the potential to cover a wide range of beam parameters. With the ability to accelerate electron bunches from femtoseconds to picoseconds in length, with a charge range from femtocoulombs to nanocoulombs, the SRF photoinjector can produce beam...
We present simulation results of a scheme to generate high-power and short FEL pulses using an electron beam with irregularly spaced current peaks. Such an electron beam produces a train of short pulses with low power in the first undulator section. In the next sections, the electron beam is delayed in a way that only one of the short pulses is continuously amplified to a very high power. The...
