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Seviour, Rebecca
TMD Jan presentation
Original Citation
Seviour, Rebecca (2015) TMD Jan presentation. In: TMD January Presentation, 12 Jan 2015, TMD,
Hayes, Middlesex, UK. (Unpublished)
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TMD Presentation
Rebecca Seviour University of Huddersfield
a'~'λ' a'<<'λ'
Metamaterial'
a~λ a << λ
Photonics Metamaterials
eigenmode simulations and network analyser measurements.HFSS results Measurement results
input PC, f0,in (GHz) 9.54234 9.5422output PC, f0,out (GHz) 9.53987 9.5379
± ±
Experimental - Numerical Verification
waveguide as
mputer
guide
connectors
were
metallic
higher
ed to
Even
it was
tube to
than the
harmonic
uated
Each
cavity structure.
Figure 1. Harmonic spectrum of 2.856-GHz klystron
Spectrum of 2.856-GHz klystron amplifier output.
Yoon Kang, Ali Nassiri, IPAC 1998
Coupling
Band Gap
Propagatio
n Bands
r/a~0.15 —> 2.55 = wa/c
—> a =8.67 mm
—> r=1.3 mm
14 GHz Lattice parameters
Monopole 14 GHz
Dipole 14.229 GHz
14.230 GHz
Quad 14.733 GHz
14.734 GHz
Sextupole 15.011 GHz
Multi-defect lattice
E field
B field
6 inputs 200 KV each
Peak E-field = 46 MV/m
Peak B-field = 120 KA/m
Monopole 14 GHz
Dipole 14.229 GHz
14.230 GHz
Quad 14.733 GHz
14.734 GHz
Sextupole 15.011 GHz
15.014.2 15.813.4 15.014.2 15.813.4
15.014.2 15.813.4
Excitation of one defect
Synchronous excitation of all defect Excitation of all defect, 1% disorder
in phase in each defect
15.014.2 15.813.4
Effects of Disorder on the Frequency and Field of Photonic Crystal Cavity Resonators.. / Matthews, C.; Seviour, Rebecca. In: Applied Physics B: Lasers and Optics, Vol. 94, No. 3, 03.2009, p. 381-388
a =8.67 mm —> ± 80 micros
r=1.3 mm —> ± 50 micros
14 GHz ~ ± 29.7 MHz [although standard CnC has ± 5 Micro accuracy]
Output Coupling
- Looks promising - Preliminary work shows coupler is feasible at 14 GHz - good input coupling - good stability - with stand high voltages
To do: - Wide lattice investigation - Improve output coupling - Improve modelling - Thermal modelling - Investigate HOM exploiting (band-width) - Investigate fabrication techniques
- Cold-press extruded rods into a base - Al mandrel, plate, acid etch away - hollow rod for water cooling
- Cold test - Consider transistor integration
- way forward ? [need effort (and money), phd or post-doc?] - STFC-case [next round may] - EPSRC [low probability of success] - TSB ?
Overview
a'~'λ' a'<<'λ'
Metamaterial'
a~λ a << λ
Photonics Effective-Media
� –
� ≈
� �– C
� �–
B
ω =
√
c2(
γn −
(
π(2n+ 1)
p+ βmm(f)
∆h
p
))2
α+ ω2c
(10)
γn = β0
p+ h−∆h
p+ βmm(ω)
∆h
p+ (2n+ 1)
π
p
α =
(
p
p+ h−∆h
)2
βmm(ω) = c−1
√
ω2εr(ω)µr(ω)− ω2c
1st order perturbation >>
Stimulated emission
Spontaneous emission
2nd order perturbation >>
Lorentz's Force Equation
2
0
dm c
γ e v
dt= − E
2
0 1 0
dm c
γ e v
dt= − E
2
2 1
1 dγ γ
2 d
γ
Δ = Δ
in
2
0
2
1
in
out
P
e
IcmΔγ
dγ
d
2
1
P
ΔP−
=
Time changing in m0c2γ (DC and AC beam energy) is
related by the E.v dot product in this equation. The
DC beam energy γdc is given by (1+Vdc/511); Vdc is
the DC beam accelerating potential. While the AC
beam energy exchange (stimulated emission) is
calculated through the Madey’s theory.
∆P
(10GHz) 1 W
E field 9.6 GHz π - Mode
Dispersion relation extracted via bead pull, black dots, with the light line shown in green.
GHz
0
2.5
5
7.5
10
1/m
0 17.5 35 52.5 70
• 2 KeV/M gradient
• Redesign SRR at lower frequency to couple more
effectively to slow-waves.
• increase beam voltage (30kev ->50Kev)
• Although CSRR breaks down @ 80W forward
power
David French (Huddersfield 2013)
Re
al
k
0
62.5
125
187.5
250
Freq [GHz]
8.00 10.00 12.00 14.00 16.00
real k
0
93.75
187.5
281.25
375
Freq [GHz]
10 10.75 11.5 12.25 13 13.75 14.5 15.25 16
hfss eigenmodeattenuation
0
0.25
0.5
0.75
1
9 10.5 12 13.5 15
S12EigenMode (real k)
Frequency GHz
S12
