Browse Prior Art Database

Magnetometer Utilizing Flux Quantization in a Thin Walled Superconducting Cylinder

IP.com Disclosure Number: IPCOM000045722D
Original Publication Date: 1983-Apr-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

McLachlan, DS: AUTHOR

Abstract

McLachlan (Phys. Rev. Lett. 28, 1434 (1969)) observed that the AC susceptibility of a thin walled (t>/-Lambda) hollow superconducting microcylinder exhibits a series of "paramagnetic" spikes as a function of magnetic field. These spikes occur at .5 H(0), 1.5 H(0), 2.5 H(0) ---, where H(0) equal 0 /cross-sectional area of the cylinder. A sketch of the results obtained and the phase diagram (proposed by P. Marcus) are shown in Figs. 1.1 and 1.2, respectively. Fig. 1.1 shows the value of H inside vs. H outside. An envelope 10 of values is shown containing the reversible path-field inside vs. field outside (11) and the position of a spike in AC susceptibility (12). Fig. 1.2 shows the AC signal or magnetic susceptibility X vs. H applied or H outside.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 67% of the total text.

Page 1 of 2

Magnetometer Utilizing Flux Quantization in a Thin Walled Superconducting Cylinder

McLachlan (Phys. Rev. Lett. 28, 1434 (1969)) observed that the AC susceptibility of a thin walled (t>/-Lambda) hollow superconducting microcylinder exhibits a series of "paramagnetic" spikes as a function of magnetic field. These spikes occur at .5 H(0), 1.5 H(0), 2.5 H(0) ---, where H(0) equal 0 /cross-sectional area of the cylinder. A sketch of the results obtained and the phase diagram (proposed by P. Marcus) are shown in Figs. 1.1 and 1.2, respectively. Fig. 1.1 shows the value of H inside vs. H outside. An envelope 10 of values is shown containing the reversible path-field inside vs. field outside (11) and the position of a spike in AC susceptibility (12). Fig. 1.2 shows the AC signal or magnetic susceptibility X vs. H applied or H outside.

Fig. 2 shows a sketch of the device. By biasing the system on the side of one of the spikes and by feeding the output of the lockin amplifier 20 into a loop coupled to the cylinder 22, the system can be made to lock onto the flux (field) enclosed in the cylinder 22. Therefore, through the field induced in the secondary of the transformer a change of the flux in the primary of the input superconducting transformer will result in a proportional change in the output of the lockin amplifier 20.

The schematic diagram shown in Fig. 2 shows a larger cylinder 22 than was used in the original experiments. The larger cylinder 22 will make the system ...