The Magnetic Field Gradiometer
| dc.contributor.author | Fraser-Smith, A.C. | |
| dc.contributor.corporate | Radioscience Laboratory Stanford Electronics Laboratories, Stanford University | en_US |
| dc.contributor.department | Physics | en_US |
| dc.date | February 1983 | |
| dc.date.accessioned | 2022-02-25T21:12:08Z | |
| dc.date.available | 2022-02-25T21:12:08Z | |
| dc.date.issued | 1983-02 | |
| dc.description | Final Technical Report No. E723-1 | en_US |
| dc.description.abstract | This report has two principal goals: First, to present a general review of magnetic field gradiometers and, second, to provide new data concerning these gradiometers, including new information about their response to magnetic dipole fields. A system of nomenclature is introduced that is consistent with the mathematical concept of gradient and which provides a basis for discussions of the different functions of magnetic field gradiometers and differential magnetometers. The distinction between component gradiometers and total field gradiometers is also stressed. An historical review provides an opportunity to describe the different characteristics of the many kinds of magnetic field gradiometers that have been developed since the first report of such a gradiometer in 1925: rotating induction loop, fixed induction loop, fluxgate, proton precession, optically pumped, and superconducting gradiometers are discussed. It is pointed out how the great sensitivity of superconducting gradiometers, and possibly other varieties of modern magnetic field gradiometers, may invalidate the popular 'source-free' asssumption under particular circumstances. Further, because these high sensitivities will make the gradiometers more susceptible to the geomagnetic field gradient, expressions are derived for the components of this gradient and some representative numerical values are calculated. The response of both component and total field gradiometers to dipole sources is considered for a number of different source-gradiometer configurations. On a more speculative note, two varieties of rotating component gradiometers are discussed, with particular attention being given to their possibly unique characteristics. The report ends by recapitulating the many applications of magnetic field gradiometers, particularly in such important areas as medicine, energy production, and defense, and by stressing the need for gradiometer-related basic research. | en_US |
| dc.description.distributionstatement | Approved for public release; distribution is unlimited. | en_US |
| dc.description.funder | N00228-81-C-AB56 | en_US |
| dc.description.sponsorship | Office of Naval Technology | en_US |
| dc.description.sponsorship | Naval Postgraduate School | en_US |
| dc.description.sponsorship | Office of Naval Research | en_US |
| dc.format.extent | 97 p. | en_US |
| dc.identifier.uri | https://hdl.handle.net/10945/68899 | |
| dc.publisher | STAR Laboratory Department or Electrical Engineering Stanford University | en_US |
| dc.rights | This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States. | en_US |
| dc.subject.author | Gradiometers | en_US |
| dc.subject.author | Magnetic Field Gradiometers | en_US |
| dc.subject.author | Magnetometers | en_US |
| dc.subject.author | Differe tial Magnetometers | en_US |
| dc.subject.author | MAD | en_US |
| dc.title | The Magnetic Field Gradiometer | en_US |
| dc.type | Report | en_US |
| dspace.entity.type | Publication |
