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Superconducting Bolometer with a Wide Range of Sensitivity

IP.com Disclosure Number: IPCOM000092010D
Original Publication Date: 1968-Aug-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

von Gutfeld, RJ: AUTHOR

Abstract

The device is an evaporated thin-film superconducting bolometer consisting of several branches or legs 1...8 arranged in a serpentine manner as in drawing 1. Thermal changes are detected by the use of a bias current supply 19 to furnish small currents, typically 1 ma, to the bolometer so that changes in voltage correspond to changes in temperature which are monitored across a voltmeter or oscilloscope V. This bolometer has the ability to make the bolometer sensitive to optical, microwave or thermal radiation in step-wise temperature intervals rather than having the full normal to superconducting transition occur at one temperature. This permits the bolometer to be used as a quasi-continuous function of temperature without the use of a magnetic field.

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Superconducting Bolometer with a Wide Range of Sensitivity

The device is an evaporated thin-film superconducting bolometer consisting of several branches or legs 1...8 arranged in a serpentine manner as in drawing
1. Thermal changes are detected by the use of a bias current supply 19 to furnish small currents, typically 1 ma, to the bolometer so that changes in voltage correspond to changes in temperature which are monitored across a voltmeter or oscilloscope V. This bolometer has the ability to make the bolometer sensitive to optical, microwave or thermal radiation in step-wise temperature intervals rather than having the full normal to superconducting transition occur at one temperature. This permits the bolometer to be used as a quasi-continuous function of temperature without the use of a magnetic field.

A cross-section of the device is shown in drawing 2. Each leg 1...8 of the circuit consists of two evaporated layers. The lower layers 9...16 each consist of a gold layer of increasing thickness with each successive leg, over which is superposed a constant thickness layer of tin 17. The varying thickness of gold can be fabricated by moving shutter 18 at constant speed if the legs are narrow compared to their separation, thus exposing each successive leg to an increased thickness of gold evaporant. Each leg then switches from normal to superconducting at a different temperature depending on the ratio of gold-to-tin thickness. The variable resistance of the cir...