TY - JOUR

T1 - Electron beam excitation of CSRR loaded waveguide for Cherenkov radiation

AU - Sharples, Emmy

AU - Letizia, Rosa

N1 - Copyright 2015 Society of Photo Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.

PY - 2015/9/1

Y1 - 2015/9/1

N2 - An electron beam is used to excite a unique electromagnetic response from a complementary split ring resonator (CSRR) metasurface loaded waveguide and investigate it as a backward propagating Cherenkov radiation source. This novel structure comprises of a metallic WR-284 waveguide loaded with four layers of CSRR-metasurface 1 mm thick, with sufficient spacing between the metasurface layers for electron beam propagation. The loaded waveguide exhibits left handed behaviour around 5.86 GHz where a TM-like mode exists. The transverse confinement of this mode between the closely lying metasurface layers and the strong electrical response of the CSRRs leads permeability and permittivity to be simultaneously negative. The structure has been optimised to reduce the surface current on the metasurface, improve the fabrication suitability and minimise the effect of hybrid modes.The structure is suitable for beam-based applications as it exhibits strong beam coupling parameters and excitation of longitudinal wake impedance at the frequency of the TM-like mode. The beam coupling parameters exhibited are high with R/Q of 36 Ω and shunt impedance of 177 kΩ. Strong excitation of the longitudinal wake impedance of 10 kΩ, with minimal transverse wake impedance and minimal beam disruption, has been observed for this mode. Results from particle-in-cell simulations will be shown to verify that backward propagating Cherenkov is radiated when a suitable electron beam propagates between the central layers of the waveguide. This investigation can lead to new solutions for non-destructive beam detection and wakefield acceleration which can potentially be scaled to higher frequency ranges.

AB - An electron beam is used to excite a unique electromagnetic response from a complementary split ring resonator (CSRR) metasurface loaded waveguide and investigate it as a backward propagating Cherenkov radiation source. This novel structure comprises of a metallic WR-284 waveguide loaded with four layers of CSRR-metasurface 1 mm thick, with sufficient spacing between the metasurface layers for electron beam propagation. The loaded waveguide exhibits left handed behaviour around 5.86 GHz where a TM-like mode exists. The transverse confinement of this mode between the closely lying metasurface layers and the strong electrical response of the CSRRs leads permeability and permittivity to be simultaneously negative. The structure has been optimised to reduce the surface current on the metasurface, improve the fabrication suitability and minimise the effect of hybrid modes.The structure is suitable for beam-based applications as it exhibits strong beam coupling parameters and excitation of longitudinal wake impedance at the frequency of the TM-like mode. The beam coupling parameters exhibited are high with R/Q of 36 Ω and shunt impedance of 177 kΩ. Strong excitation of the longitudinal wake impedance of 10 kΩ, with minimal transverse wake impedance and minimal beam disruption, has been observed for this mode. Results from particle-in-cell simulations will be shown to verify that backward propagating Cherenkov is radiated when a suitable electron beam propagates between the central layers of the waveguide. This investigation can lead to new solutions for non-destructive beam detection and wakefield acceleration which can potentially be scaled to higher frequency ranges.

U2 - 10.1117/12.2186314

DO - 10.1117/12.2186314

M3 - Journal article

VL - 9544

JO - Proceedings of SPIE

JF - Proceedings of SPIE

SN - 0277-786X

M1 - 95442L

T2 - Metamaterials, Metadevices, and Metasystems 2015

Y2 - 9 August 2015 through 13 August 2015

ER -