Crab Cavity Study with GDFIDL
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Transcript of Crab Cavity Study with GDFIDL
Crab Cavity Study with GDFIDL
Narong Chanlek and Roger Jones
20/12/06
Crab Cavity
• Crab cavities are used for the ILC in order to increase the luminosity of the colliding beams at the interaction point.
• These cavities use dipole electric field to kick the bunches into a suitable angle.
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R.M. Jones et al.,linac 2006
Crab Cavity
• TM110 dipole mode is used to operate.
• Cavity shape and field structure
(G. Burt and P. Goudket)
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Simulation
• Shape of one cell model by GDFIDL
• GDFIDL (finite difference algorithms) is used to simulate.• Higher order modes (HOMs), lower order modes (LOMs) and
same order modes (SOMs) are characterized.• Why do we need to simulate:
- HOMs, LOMs and SOMs can also be excited in the cavity.
- These mode can disrupt the bunches.
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Cavity Shape
• Geometric parameters of the cavity
shapes
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• 5 cell Niobium prototype cavity
• Schematic view of the cavity shape
Results
• Arrow plots of E-field
Monopole
@ 2.75 GHz
Quadupole
@ 5.45 GHz
dipole
@ 4.10 GHz
Sextupole
@ 6.74 GHz
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Results
• Dispersion diagram for single-cell Crab cavity
Mode used for bunch DEFLECTION 3.9 GHz
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Light line plot
Summary
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• Crab cavity uses TM110 dipole mode to rotate the
beam in order to achieve an effective collision.
• The frequency modes of Crab cavity are studied
by GDFIDL.