Enhanced polarization nuclear free precession magnetometer

Claim 1

A DEVICE FOR MEASURING THE INTENSITY OF A WEAK MAGNETIC FIELD WHICH COMPRISES, IN COMBINATION, A VESSEL, IN SAID VESSEL A SOLUTION WHERE THE SOLVENT CONTAINS A MULTIPLICITY OF ATOMIC NUCLEI HAVING A DEFINITE GYROMAGNETIC RATIO DIFFERENT FROM ZERO AND THE SOLUTE CONTAINS PARAMAGNETIC IONS WITH AN UPAIRED ELECTRON HAVING AN ELECTRONIC RESONANCE LINE DIFFERENT FROM ZERO IN A ZERO FIELD AND SATURABLE IN A HIGH FREQUENCY ALTERNATING FIELD, MEANS FOR PRODUCING IN SAID VESSEL AND ALTERNATING FIELD AT THE FREQUENCY OF SAID LINE, A COIL DISPOSED ABOUT SAID VESSEL TO BE ARANGED IN USE WITH ITS AXIS MAKING A SUBSTANTIAL ANGLE TO THE DIRECTION OF THE MAGNETIC FIELD TO BE MEASURED, A SOURCE OF DIRECT CURRENT FOR SUPPLYING CURRENT TO SAID COIL, SAID SOURCE BEING CAPABLE WHEN CONNECTED WITH SAID COIL, OF PRODUCING IN SAID SOLUTION AN AUXILIARY MAGNETIC FIELD OF A DIRECTION MAKING IN USE OF SUBSTANTIAL ANGLE TO THE DIRECTION OF THE MAGNETIC FIELD TO BE MEASURED AND OF AN INTENSITY HAVING THE SAME ORDER OF MAGNITUDE AS THAT OF THE MAGNETIC FIELD TO BE MEASURED, MEANS ADAPTED TO BE CONNECTED WITH SAID COIL FOR DISSIPATING THE ENERGY PRODUCED WHEN THE SUPPLY OF CURRENT TO SAID COIL IS CEASED, MEANS ADAPTED TO BE CONNECTED WITH SAID COIL FOR DETERMINING THE NUCLEAR LARMOR FREQUENCY OF THE ALTERNATING ELECTROMOTIVE FORCE INDUCED IN SAID COIL BY A FREE PRECESSION MOTION OF SAID ATOMIC NUCLEI IN THE FIELD TO BE MEASURED, SWITCHING MEANS FOR CONNECTING SAID COIL FIRST WITH SAID SOURCE, THEN QUICKLY WITH SAID ENERGY DISSIPATING MEANS AND THEN TO SAID FREQUENCY DETERMINING MEANS, AND CONTROL MEANS FOR OPERATING SAID SWITCHING MEANS TO HAVE SAID COIL CONNECTED WITH SAID CURRENT SOURCE FOR A TIME OF THE ORDER OF MAGNITUDE OF THE PERIOD OF SAID FREE PRECESSION MOTION, SAID PERIOD BEING EQUAL TO THE RECIPROCAL OF SAID NUCLEAR LARMOR FREQUENCY, SAID SWITCHING MEANS AND SAID CONTROL MEANS COMPRISING A CLOCK FOR DELIVERING SHORT PULSES AT REGULAR INTERVALS, A FIRST ELECTROMAGNETIC RELAY HAVING A WINDING ADAPTED TO BE ENERGIZED IN RESPONSE TO EACH OF SAID PULSES AND ALSO HAVING A CONTACT ADAPTED TO CONNECT, WHEN IN ON-POSITION, SAID COIL WITH SAID CURRENT SOURCE, A CIRCUIT FOR LENGTHENING THE DURATION OF EACH OF SAID PULSES TO GIVE LENGTHENED SIGNALS AT THE SAME REGULAR INTERVALS, AND A SECOND ELECTROMAGNETIC RELAY HAVING A WINDING ADAPTED TO BE FED IN RESPONSE TO EACH OF SAID LENGTHENED SIGNALS AND ALSO HAVING A CONTACT ADAPTED TO CONNECT, WHEN IN OFF-POSITION, SAID COIL WITH SAID FREQUENCY DETERMINING MEANS WHILE SHORT-CIRCUITING SAID ENERGY DISSIPATING MEANS, SAID LAST MENTIONED CONTACT BEING ADAPTED, WHEN IN ON-POSITION, TO GROUND SAID COIL WHILE CONNECTING SAID ENERGY DISSIPATING MEANS WITH SAID COIL.

Claim 2

A DEVICE FOR MEASURING THE INTENSITY OF A WEAK MAGNETIC FIELD WHICH COMPRISES, IN COMBINATION, A VESSEL, IN SAID VESSEL A SOLUTION WHERE THE SOLVENT CONTAINS A MULTIPLICITY OF ATOMIC NUCLEI HAVING A DEFINITE GYROMAGNETIC RATIO DIFFERENT FROM ZERO AND THE SOLUTE CONTAINS PARAMAGNETIC IONS WITH AN UPAIRED ELECTRON HAVING AN ELECTRONIC RESONANCE LINE DIFFERENT FROM ZERO IN A ZERO FIELD AND SATURABLE IN A HIGH FREQUENCY ALTERNATING FIELD, MEANS FOR PRODUCING IN SAID VESSEL AND ALTERNATING FIELD AT THE FREQUENCY OF SAID LINE, A COIL DISPOSED ABOUT SAID VESSEL TO BE ARANGED IN USE WITH ITS AXIS MAKING A SUBSTANTIAL ANGLE TO THE DIRECTION OF THE MAGNETIC FIELD TO BE MEASURED, A SOURCE OF DIRECT CURRENT FOR SUPPLYING CURRENT TO SAID COIL, SAID SOURCE BEING CAPABLE WHEN CONNECTED WITH SAID COIL, OF PRODUCING IN SAID SOLUTION AN AUXILIARY MAGNETIC FIELD OF A DIRECTION MAKING IN USE OF SUBSTANTIAL ANGLE TO THE DIRECTION OF THE MAGNETIC FIELD TO BE MEASURED AND OF AN INTENSITY HAVING THE SAME ORDER OF MAGNITUDE AS THAT OF THE MAGNETIC FIELD TO BE MEASURED, MEANS ADAPTED TO BE CONNECTED WITH SAID COIL FOR DISSIPATING THE ENERGY PRODUCED WHEN THE SUPPLY OF CURRENT TO SAID COIL IS CEASED, MEANS ADAPTED TO BE CONNECTED WITH SAID COIL FOR DETERMINING THE NUCLEAR LARMOR FREQUENCY OF THE ALTERNATING ELECTROMOTIVE FORCE INDUCED IN SAID COIL BY A FREE PRECESSION MOTION OF SAID ATOMIC NUCLEI IN THE FIELD TO BE MEASURED, SWITCHING MEANS FOR CONNECTING SAID COIL FIRST WITH SAID SOURCE, THEN QUICKLY WITH SAID ENERGY DISSIPATING MEANS AND THEN TO SAID FREQUENCY DETERMINING MEANS, AND CONTROL MEANS FOR OPERATING SAID SWITCHING MEANS TO HAVE SAID COIL CONNECTED WITH SAID CURRENT SOURCE FOR A TIME OF THE ORDER OF MAGNITUDE OF THE PERIOD OF SAID FREE PRECESSION MOTION, SAID PERIOD BEING EQUAL TO THE RECIPROCAL OF SAID NUCLEAR LARMOR FREQUENCY, SAID SWITCHING MEANS AND SAID CONTROL MEANS COMPRISING A CLOCK FOR DELIVERING SHORT PULSES AT REGULAR INTERVALS, A FIRST ELECTROMAGNETIC RELAY HAVING A WINDING ADAPTED TO BE ENERGIZED IN RESPONSE TO EACH OF SAID PULSES AND ALSO HAVING A CONTACT ADAPTED TO CONNECT, WHEN IN ON-POSITION, SAID COIL WITH SAID CURRENT SOURCE, A CIRCUIT FOR LENGTHENING THE DURATION OF EACH OF SAID PULSES TO GIVE LENGTHENED SIGNALS AT THE SAME REGULAR INTERVALS, AND A SECOND ELECTROMAGNETIC RELAY HAVING A WINDING ADAPTED TO BE FED IN RESPONSE TO EACH OF SAID LENGTHENED SIGNALS AND ALSO HAVING A CONTACT ADAPTED TO CONNECT, WHEN IN OFF-POSITION, SAID COIL WITH SAID FREQUENCY DETERMINING MEANS WHILE SHORT-CIRCUITING SAID ENERGY DISSIPATING MEANS, SAID LAST MENTIONED CONTACT BEING ADAPTED, WHEN IN ON-POSITION, TO GROUND SAID COIL WHILE CONNECTING SAID ENERGY DISSIPATING MEANS WITH SAID COIL.