A5083505767- Particle accelerators and beam dynamics
- Nuclear Physics and Applications
- Quantum and electron transport phenomena
- Physics of Superconductivity and Magnetism
- Gyrotron and Vacuum Electronics Research
- Particle Accelerators and Free-Electron Lasers
- Advanced Antenna and Metasurface Technologies
- Metamaterials and Metasurfaces Applications
- Antenna Design and Analysis
- Photonic Crystals and Applications
- Radiation Therapy and Dosimetry
- Nuclear reactor physics and engineering
- Microwave Engineering and Waveguides
- Photonic and Optical Devices
- Radiation Detection and Scintillator Technologies
- Plasma Diagnostics and Applications
- Neutrino Physics Research
- Surface and Thin Film Phenomena
- Superconducting Materials and Applications
- Quantum chaos and dynamical systems
- Molecular Junctions and Nanostructures
- Nuclear Materials and Properties
- Fern and Epiphyte Biology
- Pulsed Power Technology Applications
- Particle physics theoretical and experimental studies
University of Huddersfield
2015-2024
United States Naval Research Laboratory
2021
Lund University
2013-2014
Lancaster University
1999-2013
Cockcroft Institute
2010-2012
University of Manchester
2003
This document summarizes the work of Accelerator Working Group (AWG) International Scoping Study (ISS) a Future Neutrino Factory and Superbeam Facility. The main goal activity was to reach consensus on baseline design for complex, including proton driver parameters, choice target, front-end design, acceleration system decay ring geometry. Another explore commonality, if any, between those or Beta Beam facility. In general, requirements either latter facilities are less stringent than...
The international Muon Ionization Cooling Experiment (MICE), which is under construction at the Rutherford Appleton Laboratory (RAL), will demonstrate principle of ionization cooling as a technique for reduction phase-space volume occupied by muon beam. channels are required Neutrino Factory and Collider. MICE evaluate in detail performance single lattice cell Feasibility Study 2 channel. Beam has been constructed ISIS synchrotron RAL, Step I, it characterized using beam-instrumentation...
Microwave metamaterials show promise in numerous low-power applications, ranging from strip lines to antennas. In general, allow microwave designers obtain electromagnetic characteristics not typically available nature, leading new behavior as well reductions the size of typical devices. High-power (HPM) sources were efficient conventional source community. We consider a specific use method reduce waveguide used for power transmission, particularly, configuration which an array split-ring...
We consider the interaction between a particle beam and propagating electromagnetic wave in presence of metamaterial. show that introduction metamaterial gives rise to novel dispersion curve which determines unique relationship, via frequency dependence ability metamaterials exhibit simultaneous negative permittivity permeability. Using modified form Madey's theorem we find leads amplification EM power.
The conceptual design for a nonscaling fixed field alternating gradient accelerator suitable charged particle therapy (the use of protons and other light ions to treat some forms cancer) is described.
Temporally modulated optical media are important in both abstract and applied applications, such as spacetime transformation optics, relativistic laser-plasma interactions, dynamic metamaterials. Here we investigate the behaviour of temporal boundaries, show that traditional approaches assume constant dielectric properties, with loss incorporated an imaginary part, necessarily lead to unphysical solutions. Further, although physically reasonable predictions can be recovered a narrowband...
We considered a mesoscopic superconductor/normal metal (S/N) structure in which the N reservoirs are maintained at different temperatures. It is shown that absence of current between voltage difference $V_{T}$ arises superconducting and normal conductors. The oscillates with increasing phase $\phi $ superconductors, its magnitude does not depend on small parameter $(T/\epsilon_{F}).$
In this brief, it is demonstrated that the inclusion of primary electron elastic and inelastic reflection from surfaces vacuum RF electronic systems can result in a multipactor discharge where under current techniques predicted not to occur. Electron effectively broadens phase range over which occur, as increased energy available reflected electrons allows travel further through retarding fields via "bounce" along surface until changes favorable range. Multipactor at these neo-band points...
A numerical solution to the time evolution equation of Wigner distribution function (WDF) with an accuracy necessary simulate passage a wave packet past barrier is developed, where quantum effects require high and fine discretization. incident on barrier, portion which tunnels through, demonstrates behavior that can define various characteristic transmission reflection delay (TARD) times useful in simulation electron emission. model for TARD proposed relies only asymptotic maxima position...
We analyze the measured critical current ${I}_{m}$ in a mesoscopic four-terminal superconductor--normal-metal--superconductor (S/N/S) structure. The through S/N interface is shown to consist not only of Josephson component ${I}_{c}\mathrm{sin}\ensuremath{\varphi},$ but also phase-coherent part ${I}_{\mathrm{sg}}\mathrm{cos}\ensuremath{\varphi}$ subgap current. determined by both components ${I}_{c}$ and ${I}_{\mathrm{sg}},$ depends nonmonotonic way on voltage V between superconductors normal...
Multipactor charts for parallel plate geometries have been computed using a program that numerically solves phase equation the crossing times rather than by detailed computation of electronic paths. Motion in three-dimensional is tracked and models secondary emission elastic collisions with walls are employed. The speed advantage method allows dependence multipactor prediction on surface properties criteria, such as number electrons within shower followed, to be assessed over broad parameter range.
An experimental approach to investigate the forward scattering sum rule for periodic structures is presented. This allows an upper bound on total cross section integrated over a bandwidth from simple static problem be found. Based energy conservation, optical theorem used construct relation between and of as well single scatterers inside parallel-plate waveguide. Dynamic measurements are performed using waveguide capacitor utilized find polarizability. Convex optimization introduced identify...
Many proposed extensions of the standard model particle physics predict existence weakly interacting sub-eV particles (WISPs) such as hidden-sector photons and axions, which are also interest dark matter candidates. In this paper we propose a novel experimental approach in microwave photonic lattice structures form part 'light shining through wall'-type experiment to search for WISPs. We demonstrate potential match exceed sensitivities conventional experiments operating regime.
An electron wave packet tunneling through a barrier has transmission (or ``group delay'') time ${\ensuremath{\tau}}_{g}$ that, for rectangular barrier, is commonly held to become independent of the width $L$ as increases (the McColl-Hartman effect). In present study, it shown that first, effect dependent upon Gamow factor $\ensuremath{\theta}(k)$ vanishes, and only when large; second, triangular model field emission, although can be large small field, vanishes energy matches height.
In this paper we examine experimentally and numerically the effect of exposing a metamaterial to relatively high-power EM waves. We show that consisting conventional Split Ring Resonator on an FR4 substrate can undergo combustion when exposed 1W RF. compare experimental results numerical simulations, showing models be accurately used predict thermal behaviour metamaterials under exposure
Electron emission into a nanogap is not instantaneous, which presents difficulty in simulating ultra-fast behavior using particle models. A method of approximating the transmission and reflection delay (TARD) times wave packet interacting with barriers described by delta function, metal–insulator–metal (MIM, rectangular) barrier, Fowler Nordheim (FN, triangular) barrier given has application to simulation. It based on superposition finite number exact basis states obtained from Schrödinger’s...
In this paper, we introduce the theoretical framework underlying our proposed methodology of verification and validation (V&V) for quantum mechanical emission models using analogous macroscopic electromagnetic systems. We derive correspondence between mechanics electromagnetism transfer matrix approach describe analog that will be used to anchor atomistic tunneling simulations. Finally, illustrate by comparing systems some simple, analytically soluble examples outline future V&V work...