Advanced Resonators for AxionSearches

Tia MartineauUMass Dartmouth

University of Washington REU

8/29/2017 University of Washington REU Presentation 1

Overview

• What is dark matter?

– The axion

• Resonators as low mass axion haloscopes

• “Pizza Cavity” resonator prototypes

– Model 1

– Model 2

• Future work/Conclusions

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The Axion

• Well-motivated cold dark matter candidate

– Theorized to solve strong CP problem, characteristics match that of CDM candidates

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[1]Dark Matter and Background Light - J.M. Overduin & P.S. Wesson

A bit of cosmology

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CDM (cold dark matter) is slow compared to the speed of light

Axions were created abundantly during Big Bang

Low mass axions prevented other decay modes, so the universe would be filled with cold Bose–Einstein condensate of primordial axions. Hence, axions explain the dark matter problem

Overview

• What is dark matter?

– The axion

• Resonators as low mass axion haloscopes

• “Pizza Cavity” resonator prototypes

– Model 1

– Model 2

• Conclusions/Future work

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Axion Haloscopes and Resonators

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Axions will convert to photons in a strong inhomogeneous magnetic

field B(x)Axion Haloscopes are typically closed microwave resonators

Axions moving through magnetic field will convert when EM resonance in cavity is tuned to frequency of the photons produced. Axions detected as excess power at this frequency

Ben T. McAllister et al., Phys. Rev. Lett. 116, 161804

ADMX

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Field Cancellation Coil

SQUID Amplifier Package

Dilution Refrigerator

Antennas

8 Tesla Solenoid Magnet

Microwave Cavity

Motivation

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ADMX Projected Sensitivity up to date Jan 12 2017 source: Gray Rybka

Overview

• What is dark matter?

– The axion

• Resonators as low mass axion haloscopes

• “Pizza Cavity” resonator prototypes

– Model 1

– Model 2

• Future work/Conclusions

8/29/2017 University of Washington REU Presentation 9

Motivation

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ADMX Projected Sensitivity up to date Jan 12 2017 source: Gray Rybka

The use of dielectrics

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Allow for higher frequency searches

Can use one tunable cavity instead of multiple smaller cavities

Manipulate waveforms so we can look at other TM modes

“Pizza Cavity” Simulation

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Quasi-TM510 modeFrequency ~9.86 GHzQ-value ~2-3,000

R. Cervantes, cavity simulations, University of Washington (2017)

Potential Tuning Mechanisms

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Potential Tuning Mechanisms

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Model 1

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Model 1

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Empty Model 1 cavity reflection result

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A mess

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Model 2

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Model 2

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Model 2 Transmission Data

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Model 2 – Tracking Modes

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Overview

• What is dark matter?

– The axion

• Resonators as low mass axion haloscopes

• “Pizza Cavity” resonator prototype

– Model 1

– Model 2

• Future work/Conclusions

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Future work:

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Look into other more complex modes: whispering galleries with

more exotic materials

Focus on cavity optimization, Q value, etc.

Confirm tuning methods are workable

We still don’t have a catchy name..

PRNCESS - Pizza ResoNant Cavity Experiment using SapphireS

POP TART - PeriOdically-Placed Teflon Axion/Aluminum ResonaTor

DARTH VADER - Dark matter Axion Resonating Tube Haloscope with Vacuum And DiElectric R?

DARK - Dark matter Axion Resonating Kavity??

GRAY (Rybka) - GHz Range Axion cavitY

PENTAGRAM – Periodic rEsoNaTor for Acquiring GHz-Range Axionic Matter

ALAKAZAM - ALuminum Axion Cavity, AZimuthally A Mess

PANDeMiC - Pizza AxioN Dark Matter deteCtor

PARADOX - PizzA Resonator cAvity DetectOr Xperiment

PROTOCOl - Pizza ResOnaTOr Cavity detectOr

DANC Experiment - Dielectric AxioN Cavity Experiment

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Conclusions

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Dielectrics are beneficial in achieving high-frequencies

Similar R&D projects proven necessary to scan larger areas for axion

Funding provided in part by:

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High Energy Physics DE-SC0011665 & DE-SC0010280 & DE-AC52-07NA27344

Special thanks to:

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Dr. Gray Rybka, for (putting up with me all summer long and for) being the best mentor a girl could have,

Raphael Cervantes, for being an awesome office mate,

All of ADMX, for providing me an incredibly warm and welcoming environment to be a part of,

Jenny Smith, for being an amazing friend, and

Nick Du, because he asked to be in my acknowledgements.

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Backup Slides

Form Factor (E B)

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Will couple to the axion, form factor (E B) is positive

Will NOT couple to the axion, form factor is 0 due to cancellations

G. Carosi – ADMX, UCLA Dark Matter Symposium (2016)

Dielectrics and form factor

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Q Factor of Resonators

• The Q factor (quality factor) of a resonator is a measure of the strength of the damping of its oscillations, or for the relative linewidth.

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Model 1 (top)

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Basic geometric solution for slice size

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Method for solving for resonant frequencies

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Size comparison

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Axion Haloscopes (cont’d)

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Multiplying the cross section by the axionflux of the Milky Way dark matter halo, one obtains rate of detection

P. Sikivie, Phys. Rev. Lett. 51, 1415 – Published 17 October 1983