Numerical Calculations of Field Enhancements due to Small Grooves
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Numerical Calculations of Field Enhancements due to Small Grooves Tetsuo ABE (KEK) 5 th Collaboration Meeting on X-band Accelerator Structure Design and Test Program @SLAC, USA 2011-05-18
description
Numerical Calculations of Field Enhancements due to Small Grooves. Tetsuo ABE (KEK) 5 th Collaboration Meeting on X-band Accelerator Structure Design and Test Program @SLAC, USA 2011-05-18. (v2011.02). Computation of RF Fields by CST-MWS ~ Geometry and Definition ~. - PowerPoint PPT Presentation
Transcript of Numerical Calculations of Field Enhancements due to Small Grooves
Numerical Calculations ofField Enhancementsdue to Small Grooves
Tetsuo ABE (KEK)
5th Collaboration Meeting on
X-band Accelerator Structure Design and Test Program
@SLAC, USA
2011-05-18
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Computation of RF Fields by CST-MWS~ Geometry and Definition ~
Gap
Rectangular Waveguide with fcutoff(TE10) = 10 GHz
R=50m (fixed)
15.0mm1.0m
m
maxEnhancement Factor = ref
E
E
|| E
3 Parameters to Describe the Groove
Simulating: - Chamfer of the Quadrants - etc.
~
(v2011.02)
e.g. Gap=20m, =30m
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Meshing Parametersand
Mesh-Size Dependence
FDSolver.Method "Hexahedral Mesh" Mesh.MeshType "PBA" ‘(Perfect Boundary Approx.)Mesh.LinesPerWavelength “300" Mesh.AutomeshRefineAtPecLines "True", “RAPLRAPL"FDSolver.AccuracyHex "1e-6"
RAPL=2 (default) RAPL=5
R=
50m
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RAPL=2 (default)
(PEC)
(Vac)
X(X<0 ) 0 (X>0)
Using a function: “GetFieldVectorSurface()” Better field interpolation scheme on PEC surfaces
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RAPL=5(Adopted)
Emax
(PEC)
(Vac)
X(X<0 ) 0 (X>0)
Results
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Gap
R=50m
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Check the Results(1): E-Static Fields by CST-EMS
maxEnhancement Factor = ref
E
E
Gap
R=50m (fixed)
3 Parameters to describe the groove
10.0mm
1.0mm
~
|| E
(v2011.02)
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Meshing Parametersand
Mesh-Size Dependence
EStaticSolver.Method "Hexahedral Mesh" Mesh.MeshType "PBA" ‘(Perfect Boundary Approx.)Mesh. MinimumStepNumber “100" Mesh.AutomeshRefineAtPecLines "True", “RAPLRAPL"EStaticSolver.Accuracy "1e-9"
RAPL=2(default) RAPL=5
R=
50m
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RAPL=5(Adopted)
(PEC)
(Vac)
Emax
Comparison of the Results~Cross-Check of the Computations~
10Good Agreements as expected
CST-MWS (T. Abe) (update)
Gap (micron)
(micron)
Emax / Enominal
0 0 1.21
0 20 1.36
10 20 1.37
SLAC Omega3P (Z. Li)
Gap (micron)
(micron)
Emax / Enominal
0 0 1.23
0 20 1.40
10 20 1.44
Check the Results(2):Simulation using Omega3P (by Zenghai Li)
Fairly Good Agreements
Magnetic Field Enhancement
12|| H
e.g. R=50m, Gap=20m, =30m
TE10-likeMode
H
H
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Conclusions
• Field enhancements due to small grooves with round chamfers have been computed by using CST-MWS/EMS.– At least 20% enhancement for R=50m round chamfers.
– Increases to 40% enhancement
as the size increases to 25m.
• More simulation studies to be done– Conductor surfaces damaged by BD/discharge
– Etc.14
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End of the SlidesEnd of the Slides
