Post on 10-Aug-2020
MADMAX: introduction and status
Chang Lee on behalf of the MADMAX collaborationMPI for Physics
3rd Workshop on Microwave cavities and detectors for Axion Research Aug 24th, Livermore, CA, USA
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MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Post-inflation axion
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Our Universe:OurUniverse
PQ symmetry breaking after inflationma ~ 100 μeV
ma < 10 meV
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
High-mass challenge
• 40—400μeV (10—100 GHz): Challenging for traditional resonant cavity due to smaller volume, lower Q
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preferred by post-inflation scenarios
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
• Inverse-Primakoff in matter
• Discontinuity of ε or Be generates propagating EM field.
Axion signal
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Ea = −gaγBe
εa
E∥,1 = E∥,2 H∥,1 = H∥,2 g H1
g E1
E1 a
k1
Region 1 e1 = 4
Be
Region 2 e2 = 1
k2
g E2
E2 a
Be
x
y
z
g H2
A. J. Millar et al JCAP01(2017)061
Ea2
Ea1
Eγ1
Eγ2
Be
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
signal power• Simplest: a metallic mirror (ε = ∞)
~12 photons / day / m2 (@ 25 GHz)
• Mirror + dielectric:Leaky resonator,boost factor:
• Add more dielectric disks…
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E0 = 1.3 × 10−12 [V/m] × ( Be
10T )
Q ∝ εβ = E/E0
=λ
4n
n = 5
β ~10
standing wave
propagating wave
P ∝ E2 ∝ β2
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research !6
Mirror Dielectric Disks Receiver
Be
• more sources +coherent interferences
• Boost
β2
ν
more N!
Dielectric haloscope
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research !7
Boost• β2 > 60,000 possible
with ~80 disks.
• Disk spacings tune β.
• Broad band for coverage
• higher β for confirmation
80 discs LnAlO3
50 MHzΔνν
= 2 × 10−3
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Scan strategy• Area Law:
Psig x Δν is independent of disk spacings.
•
• Narrower peak leads to faster scan.
• In practice, ttot_adj ≈ ttot_scan.
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24.8 25.0 25.2 25.4 25.6
0
20
40
60
80
100
120
140
tscan
Δν= ( S
N )2
(kBTsys
Psig)
2
Psig ∝ B20 , β2, n, A, N,
1Δν
same area
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
collaboration
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MAgnetized Disk-and-Mirror Axion eXperiment DESY, Univ. of Hamburg, CEA-IRFU, MPI for Radioastronomy,
RWTH Aachen, Univ. of Zaragoza, MPI for Physics
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Instrument
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4K
mirror
Cover the QCD axion @ 10—100 GHz
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Simulation
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• Maxwell-Axion equation solved by analytic, FEM, ray tracing, and other methods.
• 1D calculations confirmed.
• Latest topics:3D effects, boundary loss, diffraction
dielectricdisk
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Boost measurement• Boost factor is indirectly
confirmed by the reflectivity and group delay measurements.
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-0.5
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
0
0.05
0.1
0.15
0.2
0.25
0.3
14 16 18 20 22 24
Gro
up d
elay
[ns]
Refle
ctiv
ity
Frequency [GHz]
Reflectivity MeasurementReflectivity SimulationGroup Delay MeasuredGroup Delay Simulated
Boost Factor
Reflectivity
Group Delay(scaled)
0
80 discs1
0.5
5 disks
measurementby S. Knirck & J. Egge
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
receiver chain
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FFT
(signal generator)
• 10-23 W detected in a week
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
System temperature
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• Thermal emissivity of the internal parts to be measured.goal: ΔT < 0.5 K
• Bottleneck: ~5 K noise temperature from HEMT
• Quantum noise: ~0.48K @ 20 GHz
• Latest options (JPA, TWPA, …) to be considered
tscan
Δν∝ T2
sys, Tsys = Tbg + Tamp< 4K 5~6K
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Mechanical design• Baseline design by
M. Matysek & D. Kittlinger
• 80 disks at cryogenic temp.
• Each moves 1.5—30mm w/< 60μm precision for β ~1000.
• Piezo motor for moving disks
• test @ cryogenic + high magnetic field
• Hysteresis, accuracy measurement at varying loads
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image by M. Matysek
μm
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Dielectric study
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singlecrystal
dielectrics ε = n2 tanδ
Al2O3 10 10-5
LaAlO3 24 3 x 10-5
TiO2 100 3 x 10-5
1 Sapphire + mirror
for 1 mirror + 1 disk setup at resonance
βmax = 2n −1n
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Magnets
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• Prototype magnets for R&D (2~3 years)
• 3-4 T, ~400mm bore
• Used magnets at Saclay under survey.
• Final setup (> 5 years)
• 10T dipole, B2A: ~100 T2m2, ~400 MJ stored in 2m x 1m2
• Two independent design studies by CEA Saclay & Bilfinger Noell GmbH
Noell Bilfinger
CEA Saclay
Preliminary
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Site & infrastructure
• DESY offered HERA north hall (H1)
• Large supply of LHe for magnets
• Support for magnets’ weight (~150 tons)
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image from http://h1.desy.de
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Prototype• Feasibility test & First scientific data
• starts in ~3 yrs
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Preliminary design
20 x Φ30 cm disks Mirror + motors
3~4 T
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Future perspective
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Prototype
Full scale: 80 x 1m2 disks,10T magnet in 202x?
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Summary• 40—400 μeV is an
interesting target for post-inflation QCD axion search.
• Dielectric haloscope is a promising technique.
• MADMAX is developing, aiming to cover the parameter space.
• PRL 118 091801JCAP01 (2017) 061MADMAX white paper
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MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Back-up slides
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Boost• Disks + mirror boosts signal by
β = E / E0
• Transparent mode: δ = n x d x ν = π, 3π, 5π… constructive interference.
• Resonant mode: δ = π/2, 3π/2, …disks + mirror forms a leaky resonator.
• Combined boost from both contributions.
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mirror disk
A. J. Millar et al JCAP01(2017)061
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Transfer matrix
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• Transfer matrix formalism w/ boundary conditions
A. J. Millar et al JCAP01(2017)061
E∥,1 = E∥,2 H∥,1 = H∥,2
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
list of show-stoppers
• Unexpected losses
• High tanδ, tilt, 3D loss, diffraction
• Components incompatible with high B field
• Mechanical precision too difficult.
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Incident Wave
Reflected / Transmitted Wave
MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Dielectric width
• For a set of dielectric disk with width d, how wide frequency can we cover?
• 1mm 15—30GHz
• 3mm 5—15GHz (LaAlO3)
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MADMAX: Introduction and status C. Lee
3rd Workshop on Microwave cavities and detectors for Axion Research
Fine-tuning search
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