A high-Q superconducting toroidal medium frequency detection system with a capacitively adjustable frequency range...

Area of Science:

• Experimental Physics
• Astrophysics
• Materials Science

Background:

• High-precision experiments require sensitive detectors for phenomena like dark matter.
• Existing detectors have limitations in sensitive detection bandwidth.

Purpose of the Study:

• To develop a novel cryogenic capacitor for enhanced sensitivity.
• To improve the detection bandwidth of axion haloscope experiments.

Main Methods:

• Development of a polytetrafluoroethylene/copper capacitor driven by a cryogenic piezoelectric slip-stick stage.
• Integration with superconducting toroidal LC circuits and cryogenic ultra-low-noise amplifiers.
• Cryogenic capacitance tuning and resonant frequency measurements.

Main Results:

• Demonstrated cryogenic capacitance tuning of approximately 60 pF.
• Achieved resonant frequency tuning between 345 and 685 kHz with quality factors Q > 100,000.
• Attained frequency tuning range between 520 and 710 kHz with quality factors Q > 86,000.

Conclusions:

• The new capacitor provides a versatile tool for high-precision experiments, including image current detection.
• This development increases the sensitive detection bandwidth of axion haloscopes by approximately 1000 times.
• Enables enhanced searches for axion-like dark matter conversion to radio-frequency photons.