Related papers: Field Emission in CEBAF's Superconducting RF Cavit…
We present the technical and engineering design of a medium energy (10 MeV) and high average power (1 MW) electron beam accelerator intended for irradiation treatment of high volume industrial and municipal wastewater. The accelerator uses…
An observer framework is presented for robust regulation of RF cavity fields and localized identification of disturbances in RF systems. A standard cavity field observer is augmented with additional states to estimate the evolution of…
Plasma processing of superconducting radio frequency (SRF) cavities has been an active research effort at Jefferson Lab (JLab) since 2019, aimed at enhancing cavity performance by removing hydrocarbon contaminants and reducing field…
Field Emitting Arrays (FEAs) are a promising alternative to the conventional cathodes in different vacuum electronic devices such as traveling wave tubes, electron accelerators and etc. Electrical gating and modulation capabilities,…
Circular accelerators typically have one injection and one extraction septum magnet. CEBAF is a recircuating electron linac which has a total of 27 DC current septa and one Lambertson. Current densities range from 28-48 A/mm 2 . Current…
At high field levels, field emission losses in superconducting cavities have an adverse effect in both reducing the otherwise extremely high Q > 10^9, and the magnetic breakdown field bringing it well below the critical magnetic field of…
High-power electron beams are sought-after tools in support to a wide array of societal applications. This paper investigates the production of high-power electron beams by combining a high-current field-emission electron source to a…
Jefferson Lab began a plasma processing program start-ing in the spring of 2019. Plasma processing is a common technique for removing hydrocarbons from surfaces, which increases the work function and reduces the sec-ondary emission…
The achievable beam current and beam quality of a particle accelerator can be limited by the build-up of an electron cloud (EC) in the vacuum chamber. Secondary electron emission from the walls of the vacuum chamber can contribute to the…
Many modern and proposed future particle accelerators rely on superconducting radio frequency cavities made of bulk niobium as primary particle accelerating structures. Such cavities suffer from the anomalous field dependence of their…
The application of a high electrical field on metallic surfaces leads to the well described phenomena of breakdown. In the classical scenario, explosive electron emission (EEE), breakdown (BD) originates from an emitting site (surface…
Nb3Sn is a promising next-generation material for superconducting radiofrequency cavities, with significant potential for both large scale and compact accelerator applications. However, so far, Nb3Sn cavities have been limited to cw…
We show how interference effects are responsible for manipulating the output electromagnetic field of an optical micro-resonator in the good-cavity limit. The system of interest consists in a moderately strongly pumped two-level emitter…
Significant field emission is found theoretically possible from nanorods of semiconductors of wide energy band gaps. If the nanorod has a thin surface layer containing a large number of localized states, a part of nanorod can exhibit an…
A model for the onset of the reduction in SRF cavity quality factor, the so-called Q-drop, at high accelerating electric fields is presented. Breakdown of the surface barrier against magnetic flux penetration at the cavity equator is…
We present a feasible protocol using traveling wave field to experimentally observe negative response, i.e., to obtain a decrease in the output field intensity when the input field intensity is increased. Our protocol uses one beam splitter…
The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab is investigating a significant energy upgrade utilizing Fixed-Field Alternating-gradient (FFA) recirculating arcs. This upgrade requires the design of complex…
We experimentally investigate superconducting coplanar waveguide resonators in external magnetic fields and present two strategies to reduce field-induced dissipation channels and resonance frequency shifts. One of our approaches is to…
Several authors have studied the generation of gravitational fields by condensed-matter systems in non-extreme density conditions. General Relativity and lowest-order perturbative Quantum Gravity predict in this case an extremely small…
Four DESY prototypes of the L-band superconducting RF photoinjector cavity demonstrated on-axis peak gradients above 55MV/m during multiple vertical cryogenic tests. Two of these prototypes,16G09 and 16G10, achieved these gradients with…