artificial material design for high power...
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Artificial Material Design for High Power
ApplicationsMs Aimée Hopper
Prof. Rebecca Seviour
International Institute for Accelerator Applications
University of Huddersfield
What is an Artificial [email protected]
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E=0 E E
𝐷 = 𝜖0𝐸 + 𝑃 = 𝜖𝐸
𝐵 = 𝜇0𝐻 +𝑀 = 𝜇𝐻Constitutive
Relations
Electrons
Block of Material
Nucleus
Artificial Media
• Effective Permittivity • Effective Permeability
TWT – High Power [email protected]
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ElectronBeam
RF in
RF Out
h
p
Δh
Phase ConstantY. S. Tan and R. Seviour, EPL (Europhysics Letters),
Volume 87, Issue 3 (2009)http://arxiv.org/abs/1003.5401
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𝛼 =1 − 𝑆11
2 + 𝑆212
2𝑆21
𝑛 =1
𝑘𝑑𝑐𝑜𝑠−1(𝛼)
𝑧 = −1 + 𝑠11
2 − 𝑠212
1 − 𝑠112 − 𝑠21
2
𝜀 = 𝑛/𝑧
𝜇 = 𝑛𝑧Sm
ith, D
. R
., e
t al., P
hys.R
ev. B
65.1
9 (
2002)
Experimental Results
𝜇
𝜖
High Power Design – Infinite System
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• Simulations in HFSS
• Bloch-Floquetboundary conditions
• Infinite sheet of unit cells
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Interaction at 9.9GHz|𝑆𝑖𝑗|
S11
S21
𝜇
𝜖
Frequency Dependence of 𝑆11, 𝑆21, 𝜖 and 𝜇
Frequency Dependence of Dispersion and Loss
Loaded Waveguide
• Waveguide Ports
• PEC boundaries
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Magnitude of 𝑆𝑖𝑗 comparing the infinite
system (dotted) to the loaded waveguide
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Larger Loaded Waveguide𝑆 𝑖𝑗
Frequency Dependence of
𝑆𝑖𝑗 , 𝜖 and 𝜇Dispersion and Loss
Frequency [GHz]
S11
S21
𝜖
𝜇
Future Work…
• Particle In Cell Simulations • MAGIC
• Fabricate Structure• Non Trivial
• Cold testing at Low Power
• Hot testing with electron beam
• Hot testing with High Power RF
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Conclusions
• Existing designs of artificial materials can have issues handling high power.• This only gets worse as number of unit cells in the
system increases.
• Engineered a unit cell which enables an interaction with a low power electron beam.
• Engineered a unit cell which exhibits low loss.
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Thanks
