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Josephson junction Q-spoiler

Assignee: University of California
•
Filing: 1986-03-25
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Granted: 1988-03-22
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Expires: 2006-03-25
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Abstract

Abstract An automatic Q-spoiler comprising at least one Josephson tunnel junction connected in an LC circuit for flow of resonant current therethrough. When in use in a system for detecting the magnetic resonance of a gyromagnetic particle system, a high energy pulse of high frequency energy irradiating the particle system will cause the critical current through the Josephson tunnel junctions to be exceeded, causing the tunnel junctions to act as resistors and thereby damp the ringing of the high-Q detection circuit after the pulse. When the current has damped to below the critical current, the Josephson tunnel junctions revert to their zero-resistance state, restoring the Q of the detection circuit and enabling the low energy magnetic resonance signals to be detected.

Inventors

  • 👤 John Clarke
  • 👤 Claude Hilbert
  • 👤 Erwin L. Hahn
  • 👤 Tycho Sleator

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 09:41
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/02; G01R33/035; G01R33/0354; G01R33/0358

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 57 words
In a resonant circuit having inductive and capactive components resonantly connected to each other for flow of resonant current through each other, the improvement comprising at least one Josephson tunnel junction connected in series with one of said components for flow of the same resonant current through said junction that flows through said inductive and capacitive components.
Claim 2
Dependent Claim 57 words
In a resonant circuit having inductive and capactive components resonantly connected to each other for flow of resonant current through each other, the improvement comprising at least one Josephson tunnel junction connected in series with one of said components for flow of the same resonant current through said junction that flows through said inductive and capacitive components.
Claim 3
Dependent Claim 22 words
The invention as set forth in claim 1, wherein said inductive and capactive components are connected to each other for parallel resonance.
Claim 4
Dependent Claim 22 words
The invention as set forth in claim 1, wherein said inductive and capacitive components are connected to each other for series resonance.
Claim 5
Dependent Claim 27 words
The invention as set forth in claim 1, and further including means for applying a static magnetic field parallel to the plane of said Josephson tunnel junctions.
Claim 6
Dependent Claim 24 words
The invention as set forth in claim 1, wherein there are a plurality of unshunted Josephson tunnel junctions connected in series with each other.
Claim 7
Dependent Claim 27 words
The invention as set forth in claim 5, and further including means for applying a static magnetic field parallel to the plane of said Josephson tunnel junctions.
Claim 8
Dependent Claim 161 words
A detection system for detecting the gyroprecessional resonance of a specimen having a particle system with magnetic or electric dipole moments, said detection system comprising: means for irradiating said specimen with a pulse of high frequency radiation, detector means for detecting signals produced by magnetic resonance of said specimen, a dc SQUID having a superconducting ring and two shunted Josephson tunnel junctions interrupting said ring, said ring having a bias current input at one side thereof between said junctions and a bias current output at the other side thereof between said junctions, means for establishing a constant magnetic flux threading said SQUID ring, means for supplying a bias current to said bias current input of said SQUID, an input coil inductively coupled to said SQUID ring, and a resonant circuit coupling said detector means to said input coil, said resonant circuit having inductive and reactive components and at least one Josephson tunnel junction connected in series with one of said components.
Claim 9
Dependent Claim 161 words
A detection system for detecting the gyroprecessional resonance of a specimen having a particle system with magnetic or electric dipole moments, said detection system comprising: means for irradiating said specimen with a pulse of high frequency radiation, detector means for detecting signals produced by magnetic resonance of said specimen, a dc SQUID having a superconducting ring and two shunted Josephson tunnel junctions interrupting said ring, said ring having a bias current input at one side thereof between said junctions and a bias current output at the other side thereof between said junctions, means for establishing a constant magnetic flux threading said SQUID ring, means for supplying a bias current to said bias current input of said SQUID, an input coil inductively coupled to said SQUID ring, and a resonant circuit coupling said detector means to said input coil, said resonant circuit having inductive and reactive components and at least one Josephson tunnel junction connected in series with one of said components.
Claim 10
Dependent Claim 27 words
A detection system as set forth in claim 7, and further including means for applying a static magnetic field parallel to the plane of said Josephson junction.
Claim 11
Dependent Claim 22 words
A detection system as set forth in claim 7, wherein there are a plurality of unshunted Josephson tunnel junctions connected in series.
Claim 12
Dependent Claim 27 words
A detection system as set forth in claim 8, and further including means for applying a static magnetic field parallel to the plane of said Josephson junctions.
Claim 13
Dependent Claim 74 words
A detection system as set forth in claim 7, wherein there are a plurality of Josephson tunnel junctions connected in series with one of said components, said plurality of Josephson junctions being connected as a plurality of superconducting interferometers, said interferometers being connected in series and with each interferometer comprising two Josephson junctions connected in parallel, and further including means for establishing a desired amount of magnetic flux threading the loops of the interferometers.

References Cited (Backward Citations)

SU244427A1 Cited
US3725819A Cited
US4039856A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-03-22 1991-09-21 1992-03-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-03-22 1995-09-21 1996-03-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-03-22 1999-09-21 2000-03-22 $7700.00 Window Closed / Lapsed

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