Abstract

Precision radio-frequency measurements of the magnetic susceptibility using the tunnel diode resonator (TDR) technique are used to study the delicate effects in magnetic and superconducting materials. High resolution (in ppb range) measurements are particularly important for studies of the London and Campbell penetration depths in a superconductor and for the investigation of magnetic transitions in (anti)ferromagnets. Due to the small rf magnetic-excitation in a mOe range, the TDR is especially useful at low-temperatures in a mK range, if Joule heating generated in the TDR circuitry is efficiently removed and the circuit is stabilized with sub-mK precision. Unfortunately, the circuit has significant magnetic field dependence, and therefore, most of the precision TDR measurements at low-temperatures were conducted in zero magnetic field. In this work, we describe the design of a setup for precision TDR measurements in a dilution refrigerator down to ∼40 mK with a 14 T superconducting magnet. The key features of our design are the separated electronics components and the placement of the most field sensitive parts in the field-compensated zone far from the center of solenoid as well as the heat-sinking at a higher temperature stage. The performance of the working setup is demonstrated using several superconductors.

Department(s)

Physics

Comments

U.S. Department of Energy, Grant DE-AC02-07CH11358

International Standard Serial Number (ISSN)

1089-7623; 0034-6748

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2018 American Institute of Physics (AIP), All rights reserved.

Publication Date

01 Sep 2018

PubMed ID

30278767

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