skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: High-Voltage Breakdown Penalties for the Beam-Breakup Instability

Abstract

The strength of the dangerous beam breakup (BBU) instability in linear induction accelerators (LIAs) is determined by the transverse coupling impedance Z of the induction cell cavity. For accelerating gap width w less than the beam pipe radius b, the transverse impedance is theoretically proportional to w/b, favoring narrow gaps to suppress BBU. On the other hand, cells with narrow gaps cannot support high accelerating gradients, because of electrical breakdown and shorting of the gap. Thus, there is an engineering trade-off between BBU growth and accelerating gradient, which must be considered for next generation LIAs now being designed. In this article this tradeoff is explored, using a simple pillbox cavity as an illustrative example. For this model, widening the gap to reduce the probability of breakdown increases BBU growth, unless higher magnetic focusing fields are used to further suppress the instability.

Authors:
 [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1334090
Report Number(s):
LA-UR-16-28982
TRN: US1700791
DOE Contract Number:  
AC52-06NA25396
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; BEAM DYNAMICS; INSTABILITY; BREAKDOWN; ELECTRIC POTENTIAL; CAVITY RESONATORS; INSTABILITY GROWTH RATES; ELECTRIC IMPEDANCE; INDUCTION; ELECTRICAL FAULTS; LINEAR ACCELERATORS; COUPLING; PROBABILITY; APERTURES; SIZE; Accelerators; Electron beams; High-voltage breakdown

Citation Formats

Ekdahl, Carl August. High-Voltage Breakdown Penalties for the Beam-Breakup Instability. United States: N. p., 2016. Web. doi:10.2172/1334090.
Ekdahl, Carl August. High-Voltage Breakdown Penalties for the Beam-Breakup Instability. United States. doi:10.2172/1334090.
Ekdahl, Carl August. Tue . "High-Voltage Breakdown Penalties for the Beam-Breakup Instability". United States. doi:10.2172/1334090. https://www.osti.gov/servlets/purl/1334090.
@article{osti_1334090,
title = {High-Voltage Breakdown Penalties for the Beam-Breakup Instability},
author = {Ekdahl, Carl August},
abstractNote = {The strength of the dangerous beam breakup (BBU) instability in linear induction accelerators (LIAs) is determined by the transverse coupling impedance Z⊥ of the induction cell cavity. For accelerating gap width w less than the beam pipe radius b, the transverse impedance is theoretically proportional to w/b, favoring narrow gaps to suppress BBU. On the other hand, cells with narrow gaps cannot support high accelerating gradients, because of electrical breakdown and shorting of the gap. Thus, there is an engineering trade-off between BBU growth and accelerating gradient, which must be considered for next generation LIAs now being designed. In this article this tradeoff is explored, using a simple pillbox cavity as an illustrative example. For this model, widening the gap to reduce the probability of breakdown increases BBU growth, unless higher magnetic focusing fields are used to further suppress the instability.},
doi = {10.2172/1334090},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Nov 22 00:00:00 EST 2016},
month = {Tue Nov 22 00:00:00 EST 2016}
}

Technical Report:

Save / Share: