Wire Measurement of Impedance of an XBand Accelerating Structure
Abstract
Several tens of thousands of accelerator structures will be needed for the next generation of normal conducting linear colliders known as the GLC/NLC (Global Linear Collider/Next Linear Collider). To prevent the beam being driven into a disruptive BBU (Beam BreakUp) mode or at the very least, the emittance being significantly diluted, it is important to damp down the wakefield left by driving bunches to a manageable level. Manufacturing errors and errors in design need to be measured and compared with prediction. In this paper a benchtop method of measuring transverse impedances in Xband accelerating structures is described. Utilizing an offaxis wire the S parameters are measured and converted to impedance. Measurements in a damped and detuned structure built for GLC/NLC are presented and the results are discussed.
 Authors:
 Publication Date:
 Research Org.:
 Stanford Linear Accelerator Center, Menlo Park, CA (US)
 Sponsoring Org.:
 USDOE Office of Science (US)
 OSTI Identifier:
 833027
 Report Number(s):
 SLACPUB10685
TRN: US0406505
 DOE Contract Number:
 AC0376SF00515
 Resource Type:
 Technical Report
 Resource Relation:
 Other Information: PBD: 2 Sep 2004
 Country of Publication:
 United States
 Language:
 English
 Subject:
 43 PARTICLE ACCELERATORS; ACCELERATORS; DESIGN; FORECASTING; IMPEDANCE; LINEAR COLLIDERS; MANUFACTURING
Citation Formats
Baboi, N. Wire Measurement of Impedance of an XBand Accelerating Structure. United States: N. p., 2004.
Web. doi:10.2172/833027.
Baboi, N. Wire Measurement of Impedance of an XBand Accelerating Structure. United States. doi:10.2172/833027.
Baboi, N. 2004.
"Wire Measurement of Impedance of an XBand Accelerating Structure". United States.
doi:10.2172/833027. https://www.osti.gov/servlets/purl/833027.
@article{osti_833027,
title = {Wire Measurement of Impedance of an XBand Accelerating Structure},
author = {Baboi, N},
abstractNote = {Several tens of thousands of accelerator structures will be needed for the next generation of normal conducting linear colliders known as the GLC/NLC (Global Linear Collider/Next Linear Collider). To prevent the beam being driven into a disruptive BBU (Beam BreakUp) mode or at the very least, the emittance being significantly diluted, it is important to damp down the wakefield left by driving bunches to a manageable level. Manufacturing errors and errors in design need to be measured and compared with prediction. In this paper a benchtop method of measuring transverse impedances in Xband accelerating structures is described. Utilizing an offaxis wire the S parameters are measured and converted to impedance. Measurements in a damped and detuned structure built for GLC/NLC are presented and the results are discussed.},
doi = {10.2172/833027},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2004,
month = 9
}

Dipole modes are the main cause of transverse emittance dilution in the Japanese Linear Collider/Next Linear Collider (JLC/NLC). A diagnostic setup has been built in order to investigate them. The method is based on using a coaxial wire to excite and measure electromagnetic modes of accelerating structures. This method can offer a more efficient and less expensive procedure than the ASSET facility. Initial measurements have been made and are presented in this paper.

Circuit and Scattering Matrix Analysis of the Wire Measurement Method of Beam Impedance in Accelerating Structures
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