An Introduction to the Use of SQUID Magnetometers in Biomagnetism

The advent of magnetometers with superconducting quantum interference device (SQUID) sensors has brought about a major breakthrough in magnetic field measurement. SQUID magnetometers have permitted field determinations which are orders of magnitude more sensitive than previous measurements. They have also been used in magnetometers designed to measure the magnetic moments of small specimens, such as the standard rock cylinders used in paleomagnetism and biological samples which may contain minute quantities of magnetite, of interest to biomagnetists. In the absence of an inducing field, the remanent moment of the specimen is measured. In the presence of a field, the induced moment can be measured giving the susceptibility. SQUIDs have also been used in gradiometers to obtain magnetocardiograms and magnetoencephalograms. In the latter application, fields of the order of femtoteslas (microgammas) are measured!

[1]  D. Collinson.  Instruments and techniques in paleomagnetism and rock magnetism , 1975 .

[2]  R. Powell,et al.  THERMAL CONDUCTIVITY OF METALS AND ALLOYS AT LOW TEMPERATURES. A REVIEW OF THE LITERATURE , 1954 .

[3]  A. Warnick,et al.  Digital‐Analog Magnetometer Utilizing Superconducting Sensor , 1967 .

[4]  D. Ginsberg.  Magnetic Susceptibilities of Some Materials Which May Be Used in Cryogenic Apparatus , 1970 .

[5]  G. White.  Experimental techniques in low-temperature physics , 1968 .

[6]  W. S. Goree,et al.  Magnetometers using RF-driven squids and their applications in rock magnetism and paleomagnetism , 1976 .

[7]  J. E. Zimmerman,et al.  QUANTUM STATES AND TRANSITIONS IN WEAKLY CONNECTED SUPERCONDUCTING RINGS. , 1967 .

[8]  J. King,et al.  A comparison of different magnetic methods for determining the relative grain size of magnetite in natural materials: Some results from lake sediments , 1982 .

[9]  L. Cooper,et al.  Theory of superconductivity , 1957 .

[10]  Philip W. Anderson,et al.  PROBABLE OBSERVATION OF THE JOSEPHSON SUPERCONDUCTING TUNNELING EFFECT , 1963 .

[11]  J. Clarke,et al.  A reliable DC squid made with tunnel junctions , 1975 .

[12]  M. Nisenoff.  Superconducting magnetometers with sensitivities approaching 10 -10 gauss , 1970 .

[13]  J. L. Gould,et al.  Biogenic magnetite as a basis for magnetic field detection in animals. , 1981, Bio Systems.

[14]  J. Clarke,et al.  Regulator for controlling liquid helium bath near 4.2 K. , 1978, The Review of scientific instruments.

[15]  A. A. Fife,et al.  Spatial discrimination in SQUID gradiometers and 3rd order gradiometer performance , 1982 .

[16]  Kazuo Kobayashi,et al.  Identification of the magnetic phases carrying natural remanent magnetization in certain rocks , 1964 .

[17]  J. Wheatley,et al.  Magnetic Susceptibility of Materials Commonly Used in the Construction of Cryogenic Apparatus , 1961 .

[18]  J. Clarke.  Josephson junction detectoi. , 1974, Science.

[19]  Kazuo Kobayashi,et al.  Stable remanence and memory of multi-domain materials with special reference to magnetite , 1968 .

[20]  Kazuo Kobayashi,et al.  Identification of magnetite and hematite in rocks by magnetic observation at low temperature , 1964 .

[21]  B. Josephson.  Possible new effects in superconductive tunnelling , 1962 .

[22]  J. H. Tripp,et al.  Magnetic measurement of human iron stores , 1980 .

[23]  B D Josephson,et al.  The discovery of tunneling supercurrents. , 1974, Science.

[24]  L. Néel.  Some theoretical aspects of rock-magnetism , 1955 .

[25]  M. Nabauer,et al.  Experimental Proof of Magnetic Flux Quantization in a Superconducting Ring , 1961 .

[26]  M. Fuller,et al.  Intensity determination by continuous thermal cycling , 1977 .

[27]  S. Cisowski,et al.  Interacting vs. non-interacting single domain behavior in natural and synthetic samples , 1981 .

[28]  J. Lambe,et al.  Macroscopic quantum interference in superconductors , 1965 .

[29]  J. Zimmerman,et al.  Design and Operation of Stable rf‐Biased Superconducting Point‐Contact Quantum Devices, and a Note on the Properties of Perfectly Clean Metal Contacts , 1970 .

[30]  H. Lowenstam,et al.  Magnetite in Denticle Capping in Recent Chitons (Polyplacophora) , 1962 .

[31]  E. Lüneburg,et al.  Diffraction by an infinite set of hard and soft parallel half planes , 1982 .

[32]  Bascom S. Deaver,et al.  Experimental Evidence for Quantized Flux in Superconducting Cylinders , 1961 .

[33]  B. W. Birmingham,et al.  Technology of liquid helium , 1968 .

[34]  M. Fuller,et al.  Magnetic hysteresis properties of synthetic titanomagnetites , 1976 .