High-volume tunable resonator for axion searches above 7 GHz

Journal Article · 22 April 2024 · Physical Review Applied

DOI: https://doi.org/10.1103/physrevapplied.21.l041002 · OSTI ID:2405006

Dyson, Taj A.  ^[1]; Bartram, Chelsea L. ^[2]; Davidson, Ashley ^[3]; Ezekiel, Jonah B. ^[3]; Futamura, Laura M. ^[3]; Liu, Tongtian  ^[3]; Kuo, Chao-Lin  ^[4]

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1. Stanford University, CA (United States); SLAC
2. SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
3. Stanford University, CA (United States)
4. Stanford University, CA (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)

In this research, we present results from an experimental demonstration of a tunable thin-shell axion haloscope whose geometry decouples its overall volume from its resonant frequency, thereby evading the steep sensitivity degradation at high frequencies. An aluminum 2.6-l (41⁢λ³) prototype, which tunes from 7.1 to 8.0 GHz, was fabricated and characterized at room temperature. An axion-sensitive, straightforwardly tunable TM₀₁₀ mode is clearly identified with a room-temperature quality factor, Q, of approximately 5000. The on-resonance E-field distribution is mapped and found to agree with numerical calculations. Anticipating future cryogenic operation, we develop an alignment protocol relying only on rf measurements of the cavity, maintaining a form factor of 0.57 across the full tuning range. These measurements demonstrate the feasibility of cavity-based haloscopes with operating volume V $$\gg$$ λ³. We discuss plans for future development and the parameters required for a thin-shell haloscope exploring the postinflationary axion parameter space (approximately 4 to 30 GHz) at Dine-Fischler-Srednicki-Zhitnitsky sensitivity.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: National Science Foundation; Natural Sciences and Engineering Research Council of Canada (NSERC); USDOE; USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC)
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 2405006
• Journal Information: Physical Review Applied, Journal Name: Physical Review Applied Journal Issue: 4 Vol. 21; ISSN 2331-7019
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English