Spin resonance spectrometer and magnet structure
AssigneeBell Telephone Laboratories, Incorporated
InventorsLouis William Rupp, Jr., Walter Michael Walsh, Jr.
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Abstract
A permanent magnet structure provides high fields (e.g., .about. 4500 Gauss) with excellent uniformity (e.g., .+-. 3 Gauss) over a moderately large volume of the gap (e.g., approximately 20 percent of the gap diameter and gap width). This is accomplished by grinding away a portion of the permanent magnet material at the center of each face of the gap to form a depression, deepest at the center of the face. The magnet may include means for varying the gap width and a modulating coil for low frequency minor variation of the magnetic field. The magnet structure is used in conjunction with a 12 GHz self-excited spin resonance cavity to form a compact, portable electron spin resonance spectrometer.
Claims7
A magnet structure comprising:
- a. a pair of coaxial permanent magnets, each of which is circularly symmetric about the common axis, and each of which possesses a first face and a a second face, the first faces of which are spaced from one another to form a gap free from domain magnetic material, the magnets being axially magnetized with poles of opposite polarity facing one another;
- and
- b. a housing including soft magnetic material in contact with the permanent magnets at the second face of each magnet, the housing holding the magnets in spaced relationship and providing a return path for magnetic flux around the gap characterized in that the first face of each permanent magnet forms an axial depression so shaped as to be monotonically deeper toward the axis, whereby the radial and axial uniformity of the magnetic field at the center of the gap is improved.
Dependencies are inferred from the claim text.