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Title: Advanced Accelerating Structures and Their Interaction with Electron Beams

Abstract

In this paper, we give a brief description of several advanced accelerating structures, such as dielectric loaded waveguides, photonic band gap, metamaterials and improved iris-loaded cavities. We describe wakefields generated by passing high current electron beams through these structures, and applications of wakefields to advanced accelerator schemes. One of the keys to success for high gradient wakefield acceleration is to develop high current drive beam sources. As an example, the high current RF photo injector at the Argonne Wakefield Accelerator, passed a {approx}80 nC electron beam through a high gradient dielectric loaded structure to achieve a 100 MV/m gradient. We will summarize recent related experiments on beam-structure interactions and also discuss high current electron beam generation and propagation and their applications to wakefield acceleration.

Authors:
 [1]
  1. High Energy Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)
Publication Date:
OSTI Identifier:
21255254
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1086; Journal Issue: 1; Conference: 13. advanced accelerator concepts workshop, Santa Cruz, CA (United States), 27 Jul - 2 Aug 2008; Other Information: DOI: 10.1063/1.3080940; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ACCELERATION; DIELECTRIC MATERIALS; ELECTRON BEAMS; INTERACTIONS; WAKEFIELD ACCELERATORS; WAVEGUIDES

Citation Formats

Gai Wei. Advanced Accelerating Structures and Their Interaction with Electron Beams. United States: N. p., 2009. Web. doi:10.1063/1.3080940.
Gai Wei. Advanced Accelerating Structures and Their Interaction with Electron Beams. United States. doi:10.1063/1.3080940.
Gai Wei. 2009. "Advanced Accelerating Structures and Their Interaction with Electron Beams". United States. doi:10.1063/1.3080940.
@article{osti_21255254,
title = {Advanced Accelerating Structures and Their Interaction with Electron Beams},
author = {Gai Wei},
abstractNote = {In this paper, we give a brief description of several advanced accelerating structures, such as dielectric loaded waveguides, photonic band gap, metamaterials and improved iris-loaded cavities. We describe wakefields generated by passing high current electron beams through these structures, and applications of wakefields to advanced accelerator schemes. One of the keys to success for high gradient wakefield acceleration is to develop high current drive beam sources. As an example, the high current RF photo injector at the Argonne Wakefield Accelerator, passed a {approx}80 nC electron beam through a high gradient dielectric loaded structure to achieve a 100 MV/m gradient. We will summarize recent related experiments on beam-structure interactions and also discuss high current electron beam generation and propagation and their applications to wakefield acceleration.},
doi = {10.1063/1.3080940},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1086,
place = {United States},
year = 2009,
month = 1
}
  • In this paper, we give a brief description of several advanced accelerating structures, such as dielectric loaded waveguides, photonic band gap, metamaterials and improved iris-loaded cavities. We describe wakefields generated by passing high current electron beams through these structures, and applications of wakefields to advanced accelerator schemes. One of the keys to success for high gradient wakefield acceleration is to develop high current drive beam sources. As an example, the high current RF photo injector at the Argonne Wakefield Accelerator, passed a {approx}80 nC electron beam through a high gradient dielectric loaded structure to achieve a 100 MV/m gradient. Wemore » will summarize recent related experiments on beam-structure interactions and also discuss high current electron beam generation and propagation and their applications to wakefield acceleration.« less
  • A time-dependent nonlinear analysis of a helix traveling wave tube is presented for a beam propagating through a sheath helix surrounded by a conducting wall. The effects of dielectric- and vane-loading are included as is the tapering of the helix pitch. Dielectric-loading is described when the gap between the helix and the wall is uniformly filled. Vane-loading describes the insertion of vanes running the length of the helix. The field is represented as a superposition of azimuthally symmetric waves {ital in vacuo}. An overall explicit sinusoidal variation is assumed, and the polarization and radial variation of each wave is determinedmore » by the boundary conditions in a vacuum circuit. The propagation of each wave as well as the interaction with the beam is included by allowing the amplitudes of the waves to vary in z and t. A dynamical equation is derived analogously to Poynting{close_quote}s equation, and solved in conjunction with the 3-D Lorentz force equations. The model is compared with linear theory. {copyright} {ital 1997 American Institute of Physics.}« less
  • A time-dependent nonlinear analysis of a helix traveling wave tube is presented for a beam propagating through a sheath helix surrounded by a conducting wall. The effects of dielectric- and vane-loading are included as is the tapering of the helix pitch. Dielectric-loading is described when the gap between the helix and the wall is uniformly filled. Vane-loading describes the insertion of vanes running the length of the helix. The field is represented as a superposition of azimuthally symmetric waves in vacuo. An overall explicit sinusoidal variation is assumed, and the polarization and radial variation of each wave is determined bymore » the boundary conditions in a vacuum circuit. The propagation of each wave as well as the interaction with the beam is included by allowing the amplitudes of the waves to vary in z and t. A dynamical equation is derived analogously to Poynting's equation, and solved in conjunction with the 3-D Lorentz force equations. The model is compared with linear theory.« less
  • This paper presents designs for four types of very-low-velocity superconducting (SC) accelerating cavity capable of providing several MV of accelerating potential per cavity, and suitable for particle velocities in the range 0.006<v/c<0.06. Superconducting TEM-class cavities have been widely applied to cw acceleration of ion beams. SC linacs can be formed as an array of independently phased cavities, enabling a variable velocity profile to maximize the output energy for each of a number of different ion species. Several laboratories in the U.S. and Europe are planning exotic beam facilities based on SC linacs. The cavity designs presented here are intended formore » the front end of such linacs, particularly for the postacceleration of rare isotopes of low charge state. Several types of SC cavities have been developed recently to cover particle velocities above 0.06c. Superconducting four-gap quarter-wave resonators for velocities 0.008<{beta}=v/c<0.05 were developed about two decades ago and have been successfully operated at the ATLAS SC linac at Argonne National Laboratory. Since that time, progress in simulation tools, cavity fabrication, and processing have increased SC cavity gradients by a factor of 3-4. This paper applies these tools to optimize the design of a four-gap quarter-wave resonator for exotic beam facilities and other low-velocity applications.« less