skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: High-resolution room-temperature sample scanning superconducting quantum interference device microscope configurable for geological and biomagnetic applications

Abstract

We have developed a scanning superconducting quantum interference device (SQUID) microscope system with interchangeable sensor configurations for imaging magnetic fields of room-temperature (RT) samples with submillimeter resolution. The low-critical-temperature (T{sub c}) niobium-based monolithic SQUID sensors are mounted on the tip of a sapphire and thermally anchored to the helium reservoir. A 25 {mu}m sapphire window separates the vacuum space from the RT sample. A positioning mechanism allows us to adjust the sample-to-sensor spacing from the top of the Dewar. We achieved a sensor-to-sample spacing of 100 {mu}m, which could be maintained for periods of up to four weeks. Different SQUID sensor designs are necessary to achieve the best combination of spatial resolution and field sensitivity for a given source configuration. For imaging thin sections of geological samples, we used a custom-designed monolithic low-T{sub c} niobium bare SQUID sensor, with an effective diameter of 80 {mu}m, and achieved a field sensitivity of 1.5 pT/Hz{sup 1/2} and a magnetic moment sensitivity of 5.4x10{sup -18} A m{sup 2}/Hz{sup 1/2} at a sensor-to-sample spacing of 100 {mu}m in the white noise region for frequencies above 100 Hz. Imaging action currents in cardiac tissue requires a higher field sensitivity, which can only be achieved bymore » compromising spatial resolution. We developed a monolithic low-T{sub c} niobium multiloop SQUID sensor, with sensor sizes ranging from 250 {mu}m to 1 mm, and achieved sensitivities of 480-180 fT/Hz{sup 1/2} in the white noise region for frequencies above 100 Hz, respectively. For all sensor configurations, the spatial resolution was comparable to the effective diameter and limited by the sensor-to-sample spacing. Spatial registration allowed us to compare high-resolution images of magnetic fields associated with action currents and optical recordings of transmembrane potentials to study the bidomain nature of cardiac tissue or to match petrography to magnetic field maps in thin sections of geological samples.« less

Authors:
; ; ; ; ;  [1]
  1. Vanderbilt University, Nashville, Tennessee 37235 (United States)
Publication Date:
OSTI Identifier:
20722208
Resource Type:
Journal Article
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 76; Journal Issue: 5; Other Information: DOI: 10.1063/1.1884025; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0034-6748
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; CONFIGURATION; CRITICAL TEMPERATURE; DESIGN; HELIUM; IMAGES; MAGNETIC FIELDS; MAGNETIC MOMENTS; MAGNETOMETERS; MICROSCOPES; NIOBIUM; NOISE; SAPPHIRE; SENSITIVITY; SPATIAL RESOLUTION; SQUID DEVICES; TEMPERATURE RANGE 0273-0400 K; USES

Citation Formats

Fong, L E, Holzer, J R, McBride, K K, Lima, E A, Baudenbacher, F, Radparvar, M, and Hypres Inc., Elmsford, New York 10523. High-resolution room-temperature sample scanning superconducting quantum interference device microscope configurable for geological and biomagnetic applications. United States: N. p., 2005. Web. doi:10.1063/1.1884025.
Fong, L E, Holzer, J R, McBride, K K, Lima, E A, Baudenbacher, F, Radparvar, M, & Hypres Inc., Elmsford, New York 10523. High-resolution room-temperature sample scanning superconducting quantum interference device microscope configurable for geological and biomagnetic applications. United States. doi:10.1063/1.1884025.
Fong, L E, Holzer, J R, McBride, K K, Lima, E A, Baudenbacher, F, Radparvar, M, and Hypres Inc., Elmsford, New York 10523. Sun . "High-resolution room-temperature sample scanning superconducting quantum interference device microscope configurable for geological and biomagnetic applications". United States. doi:10.1063/1.1884025.
@article{osti_20722208,
title = {High-resolution room-temperature sample scanning superconducting quantum interference device microscope configurable for geological and biomagnetic applications},
author = {Fong, L E and Holzer, J R and McBride, K K and Lima, E A and Baudenbacher, F and Radparvar, M and Hypres Inc., Elmsford, New York 10523},
abstractNote = {We have developed a scanning superconducting quantum interference device (SQUID) microscope system with interchangeable sensor configurations for imaging magnetic fields of room-temperature (RT) samples with submillimeter resolution. The low-critical-temperature (T{sub c}) niobium-based monolithic SQUID sensors are mounted on the tip of a sapphire and thermally anchored to the helium reservoir. A 25 {mu}m sapphire window separates the vacuum space from the RT sample. A positioning mechanism allows us to adjust the sample-to-sensor spacing from the top of the Dewar. We achieved a sensor-to-sample spacing of 100 {mu}m, which could be maintained for periods of up to four weeks. Different SQUID sensor designs are necessary to achieve the best combination of spatial resolution and field sensitivity for a given source configuration. For imaging thin sections of geological samples, we used a custom-designed monolithic low-T{sub c} niobium bare SQUID sensor, with an effective diameter of 80 {mu}m, and achieved a field sensitivity of 1.5 pT/Hz{sup 1/2} and a magnetic moment sensitivity of 5.4x10{sup -18} A m{sup 2}/Hz{sup 1/2} at a sensor-to-sample spacing of 100 {mu}m in the white noise region for frequencies above 100 Hz. Imaging action currents in cardiac tissue requires a higher field sensitivity, which can only be achieved by compromising spatial resolution. We developed a monolithic low-T{sub c} niobium multiloop SQUID sensor, with sensor sizes ranging from 250 {mu}m to 1 mm, and achieved sensitivities of 480-180 fT/Hz{sup 1/2} in the white noise region for frequencies above 100 Hz, respectively. For all sensor configurations, the spatial resolution was comparable to the effective diameter and limited by the sensor-to-sample spacing. Spatial registration allowed us to compare high-resolution images of magnetic fields associated with action currents and optical recordings of transmembrane potentials to study the bidomain nature of cardiac tissue or to match petrography to magnetic field maps in thin sections of geological samples.},
doi = {10.1063/1.1884025},
journal = {Review of Scientific Instruments},
issn = {0034-6748},
number = 5,
volume = 76,
place = {United States},
year = {2005},
month = {5}
}