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Title: Measurements of electron beam deflection and rf breakdown rate from a surface wave guided in metallic mm-wave accelerating structures

Abstract

Here, experiments with high gradient traveling-wave mm-wave metallic accelerating structures were performed to research the physics of vacuum rf breakdowns. The accelerating structures are open, composed of two identical halves separated by an adjustable gap. The electromagnetic fields were induced by an ultrarelativistic electron beam at the Facility for Advanced Accelerator Experimental Tests (FACET) at SLAC National Accelerator Laboratory. These accelerating structures have a fundamental beam-synchronous mode with a frequency that varies from 95 to 140 GHz depending on the gap width. When the gap is opened by more than half of a freespace wavelength, the corresponding synchronous mode remains trapped demonstrating behavior consistent with the so called “surface wave.” This regime is of potential interest for femtosecond electron beam diagnostics and beam manipulation techniques. The behavior of the surface wave was characterized and the measured synchronous frequency, pulse length and beam deflection voltage are found to be in good agreement with simulations. The wave magnitude was changed by positioning the beam at different distances from the surface of a structure-half and the corresponding rf breakdown rate was recorded. The breakdown rate was 4 × 10 -3 per pulse at a peak surface electric field of 0.3 GV/m and amore » pulse length of 60 ps.« less

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [2];  [1];  [1]
  1. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  2. National Inst. of Nuclear Physics (INFN), Frascati (Italy). National Lab. of Frascati (INFN-LNF)
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1470593
Alternate Identifier(s):
OSTI ID: 1471663
Grant/Contract Number:  
AC02-76SF00515
Resource Type:
Published Article
Journal Name:
Physical Review Accelerators and Beams
Additional Journal Information:
Journal Volume: 21; Journal Issue: 9; Journal ID: ISSN 2469-9888
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; beam diagnostics; electromagnetism; room temperature RF

Citation Formats

Dal Forno, Massimo, Dolgashev, Valery, Bowden, Gordon, Clarke, Christine, Hogan, Mark, McCormick, Doug, Novokhatski, Alexander, O’Shea, Brendan, Spataro, Bruno, Weathersby, Stephen, and Tantawi, Sami G. Measurements of electron beam deflection and rf breakdown rate from a surface wave guided in metallic mm-wave accelerating structures. United States: N. p., 2018. Web. doi:10.1103/PhysRevAccelBeams.21.091301.
Dal Forno, Massimo, Dolgashev, Valery, Bowden, Gordon, Clarke, Christine, Hogan, Mark, McCormick, Doug, Novokhatski, Alexander, O’Shea, Brendan, Spataro, Bruno, Weathersby, Stephen, & Tantawi, Sami G. Measurements of electron beam deflection and rf breakdown rate from a surface wave guided in metallic mm-wave accelerating structures. United States. doi:10.1103/PhysRevAccelBeams.21.091301.
Dal Forno, Massimo, Dolgashev, Valery, Bowden, Gordon, Clarke, Christine, Hogan, Mark, McCormick, Doug, Novokhatski, Alexander, O’Shea, Brendan, Spataro, Bruno, Weathersby, Stephen, and Tantawi, Sami G. Thu . "Measurements of electron beam deflection and rf breakdown rate from a surface wave guided in metallic mm-wave accelerating structures". United States. doi:10.1103/PhysRevAccelBeams.21.091301.
@article{osti_1470593,
title = {Measurements of electron beam deflection and rf breakdown rate from a surface wave guided in metallic mm-wave accelerating structures},
author = {Dal Forno, Massimo and Dolgashev, Valery and Bowden, Gordon and Clarke, Christine and Hogan, Mark and McCormick, Doug and Novokhatski, Alexander and O’Shea, Brendan and Spataro, Bruno and Weathersby, Stephen and Tantawi, Sami G.},
abstractNote = {Here, experiments with high gradient traveling-wave mm-wave metallic accelerating structures were performed to research the physics of vacuum rf breakdowns. The accelerating structures are open, composed of two identical halves separated by an adjustable gap. The electromagnetic fields were induced by an ultrarelativistic electron beam at the Facility for Advanced Accelerator Experimental Tests (FACET) at SLAC National Accelerator Laboratory. These accelerating structures have a fundamental beam-synchronous mode with a frequency that varies from 95 to 140 GHz depending on the gap width. When the gap is opened by more than half of a freespace wavelength, the corresponding synchronous mode remains trapped demonstrating behavior consistent with the so called “surface wave.” This regime is of potential interest for femtosecond electron beam diagnostics and beam manipulation techniques. The behavior of the surface wave was characterized and the measured synchronous frequency, pulse length and beam deflection voltage are found to be in good agreement with simulations. The wave magnitude was changed by positioning the beam at different distances from the surface of a structure-half and the corresponding rf breakdown rate was recorded. The breakdown rate was 4 × 10-3 per pulse at a peak surface electric field of 0.3 GV/m and a pulse length of 60 ps.},
doi = {10.1103/PhysRevAccelBeams.21.091301},
journal = {Physical Review Accelerators and Beams},
number = 9,
volume = 21,
place = {United States},
year = {2018},
month = {9}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1103/PhysRevAccelBeams.21.091301

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