Magnetoresistance in copper at high frequency and high magnetic fields

Abstract

A: In halo dark matter axion search experiments, cylindrical microwave cavities are typically employed to detect signals from the axion-photon conversion. To enhance the conversion power and reduce the noise level, cavities are placed in strong solenoid magnetic fields at sufficiently low temperatures. Exploring high mass regions in cavity-based axion search experiments requires high frequency microwave cavities and thus understanding cavity properties at high frequencies in extreme conditions is deemed necessary. We present a study of the magnetoresistance of copper using a cavity with a resonant frequency of 12.9 GHz at the liquid helium temperature in magnetic fields up to 15 T utilizing a second generation high temperature superconducting magnet. The observations are interpreted to be consistent with the anomalous skin effect and size effect. This is the first measurement of magnetoresistance at a high frequency (> 10 GHz) in high magnetic fields (> 10 T). K: Dark Matter detectors (WIMPs, axions, etc.); Detector design and construction technologies and materials; Microwave radiometers A X P : 1705.04754

Maintaining high Q-factor of superconducting YBa$_2$Cu$_3$O$_{7-x}$ microwave cavity in a high magnetic field

“…For the fundamental TM modes most commonly used in axion search, the vertical cuts of the cylindrical cavity do not make any significant degradation of the Q-factor, since the direction of the surface current in TM 010 mode and the boundary of each cavity piece are parallel as seen in FIG. 2B, which was already demonstrated by the Center for Axion and Precision Physics research (CAPP) [12]. We have confirmed it by COMSOL simulation and the Q-factor measurement of an assembled cavity.…”

Exploiting higher-order resonant modes for axion haloscopes

“…We employed a split-type cavity design, which was initially introduced in Ref. [16]. Made of oxygen-free high conductivity copper, the cavity consists of three identical pieces.…”

High magnetic fields for fundamental physics

“…No-insulation, high temperature superconducting magnets, were first introduced in 2010 at the MIT lab of Francis Bitter [147,148]. The Center for Axion and Precision Physics Research at the Institute for Basic Science of the Republic of Korea (IBS-CAPP) already has in its laboratory two HTS, no-insulation magnets [149] made by SuNAM (http://www.i-sunam.com). One magnet with an aperture of 3.5 cm is capable of reaching 26 T , while the second one is capable of providing 18 T in a 7 cm inner diameter, over 40 cm long magnet-bore aperture.…”