Development of the corrugated waveguide-based colinear wakefield accelerator at Argonne National Laboratory (ANL) for a compact hard x-ray free-electron laser (FEL) facility has passed a milestone with the demonstration of most principal accelerator and FEL components: a 30 cm long strong-back structure to hold and cool the corrugated waveguide, sub-terahertz frequency electromagnetic couplers...
The global collaboration between PAL, NIU, ANL, and KU is ongoing to develop an electron beam-driven THz power generation and two-beam acceleration in SWFA. We successfully demonstrated the fabrication of a 0.2 THz structure and the characteristic of wakefield using the beam-based experimental measurement. of a 0.2 THz structure a few years ago. The success of a new fabrication method led us...
This paper presents the final physics design of the THz wakefield acceleration experiment using three dielectric structure cross-sections at the Argonne Wakefield Accelerator (AWA) facility. The experiment will focus on multi-bunch excitation of wakefields, exploration of the wakefield transverse-force topology, and possibly support an experiment on energy recovery. This contribution discusses...
A comparative analysis of two types of dielectric laser accelerators (DLA) based on periodic (grating) and flat dielectric structures to accelerate electrons in the energy range from 300 KEV to 3 GEV is presented. The main attention is paid to the conditions, efficiency and restrictions of each acceleration method, as well as the influence of laser radiation parameters on electron acceleration...
Two-beam acceleration is a powerful method to generate high accelerating fields by utilizing short radiofrequency pulses. The Argonne Wakefield Accelerator facility is applying a two-beam acceleration approach to an X-band radiofrequency gun. This gun has experimentally demonstrated an electric field on the photocathode of ~400 MV/m. The next phase of this experiment will involve adding a...
Because of their ability to produce high gradients, radiofrequency (RF) structures in the sub-terahertz (sub-THz) regime are of considerable interest in structure wakefield acceleration. These structures can be used to generate a high gradient and high efficiency wakefield, allowing for a low physical footprint. In the pursuit of a structure with these properties, we have designed and built a...
The generation of high spectral brilliance radiation with electron beam sources relies heavily on the qualities of the electron transverse emittance and its longitudinal compression which significantly affect X-ray generation efficiency in Inverse Compton Scattering. Designing and building such a system in a compact formfactor requires non-trivial solutions starting from electrons generation...
Structure-based wakefield acceleration (SWFA) is a proposed concept to overcome limitations in conventional accelerators. This approach allows for the creation of short-input radiofrequency (rf) pulses, which have been empirically shown to reduce breakdown rates at a given gradient. Metamaterial structures with negative group velocity have shown promise in accelerator applications. A structure...
RF breakdown limits the attainable acceleration gradient in normal conducting RF structures, challenging high-gradient operations. Recent experiments at the Argonne Wakefield Accelerator (AWA) suggests short RF pulses (a few nanoseconds) can mitigate this breakdown. We simulated dark current emission in the short-pulse regime to study breakdown initiators including field emission and...
We consider to develop GeV-level high-gradient linacs. These accelerators will be based on an short-pulse cryogenically cooled copper technology that will provide a gradient of 300 MV/m or higher. Since there is a shortage of high-power nanosecond RF sources, we propose the development of the pulse compression methods. Instead of passive pulse compressors like SLED, SLED-II and its recent...
In this talk we will present results from high gradient structure testing of single, multi-cell and meter-scale accelerating structures. Structures were tested with a variety of fabrication techniques including brazing, diffusion bonding and clamped plated structures. Target gradients of 120 MeV/m were achieved and exceeded. Designs and performance of rf components (loads, windows, etc.) for...