US3742212A — Method and apparatus for pulsed ion cyclotron res…

Claim 1

Independent Claim 161 words

In a pulsed ion cyclotron resonance spectrometer, an analyzer cell, means for forming ions within said cell from a sample during an ionizing period, means including a unidirectional magnetic field and static electric fields for trapping substantially all ions of a given charge sign formed in said cell including ions formed therewithin during the ionizing period, causing them to move orbitally at angular frequencies dependent upon the charge-tomass ratio thereof, alternating electric field producing means for supplying an alternating electric field to said trapped ions normal to said unidirectional magnetic field, and means including the alternating electric field supplied by said alternating electric field producing means for producing ion cyclotron resonance of trapped ions having a given charge-tomass ratio while ions of different charge-to-mass ratio remain non-resonant therewith during a detection time period after a reaction time delay period following the ionizing period, said alternating electric field being non-resonant with all trapped ions at all times outside the detection time period.

Claim 2

Dependent Claim 161 words

In a pulsed ion cyclotron resonance spectrometer, an analyzer cell, means for forming ions within said cell from a sample during an ionizing period, means including a unidirectional magnetic field and static electric fields for trapping substantially all ions of a given charge sign formed in said cell including ions formed therewithin during the ionizing period, causing them to move orbitally at angular frequencies dependent upon the charge-tomass ratio thereof, alternating electric field producing means for supplying an alternating electric field to said trapped ions normal to said unidirectional magnetic field, and means including the alternating electric field supplied by said alternating electric field producing means for producing ion cyclotron resonance of trapped ions having a given charge-tomass ratio while ions of different charge-to-mass ratio remain non-resonant therewith during a detection time period after a reaction time delay period following the ionizing period, said alternating electric field being non-resonant with all trapped ions at all times outside the detection time period.

Claim 3

Dependent Claim 114 words

The pulsed ion cyclotron resonance spectrometer as defined in claim 1 wherein, said analyzer cell comprises at least six spaced electrodes including, (1) first and second electrodes forming first opposite sides, (2) third and fourth electrodes forming second opposite sides, and (3) fifth and sixth electrodes forming third opposite sides, the lines of force of said unidirectional magnetic field extending across the cell in a direction generally parallel with the third, fourth, fifth and sixth electrodes, and said static electric fields being produced by means for applying a trapping potential of one polarity to the first and second electrodes, and a trapping potential of opposite polarity to the third, fourTh, fifth and sixth electrodes.

Claim 4

Dependent Claim 33 words

The pulsed ion cyclotron resonance spectrometer as defined in claim 1 including, means for detecting the ion cyclotron resonance of said resonant ions having said given charge-to-mass ratio during the detection time period.

Claim 5

Dependent Claim 54 words

The pulsed ion cyclotron resonance spectrometer as defined in claim 3 wherein said means for detecting the ion cyclotron resonance of said resonant ions having said given charge-to-mass ratio during the detection time period comprises, a gated integrator which is responsive to the alternating electric field producing means only during the detection time period.

Claim 6

Dependent Claim 81 words

The pulsed ion cyclotron resonance spectrometer as defined in claim 1 including, means for irradiating the trapped ions with an alternating electric field at the ion cyclotron resonance frequency of a group of the trapped ions during an irradiating period occurring during a portion of the reaction time period prior to the detection time period to accelerate all ions of said group in an amount dependent upon the strength of the irradiating alternating electric field and length of the irradiating period.

Claim 7

Dependent Claim 60 words

The pulsed ion cyclotron resonance spectrometer as defined in claim 1 wherein, said means for producing ion cyclotron resonance of trapped ions having a given charge-to-mass ratio during a detection time period includes means for bringing the alternating electric field and angular frequency of the orbiting ions of said given charge-to-mass ratio into resonance only during the detection time period.

Claim 8

Dependent Claim 50 words

The pulsed ion cyclotron resonance spectrometer as defined in claim 6 wherein said means for bringing the alternating electric field and angular frequency of the orbiting ions of said given charge-to-mass ratio into resonance comprises means for changing the magnitude of the static electric fields during the detection time period.

Claim 9

Dependent Claim 22 words

The pulsed ion cyclotron resonance spectrometer as defined in claim 1 including, means for neutralizing the ions after the detection time period.

Claim 10

Dependent Claim 30 words

The pulsed ion cyclotron resonance spectrometer as defined in claim 8 including, means for sequentially operating said ion forming means, ion cyclotron resonance producing means, and said ion neutralizing means.

Claim 11

Dependent Claim 71 words

The pulsed ion cyclotron resonance spectrometer as defined in claim 9 including, means for cyclically operating the spectrometer for repeated sequential operation of said ion forming means, ion cyclotron resonance producing means, and ion neutralizing means, and means for scanning the reaction time delay period during succeeding cycles of operation for determination of the concentration of the excited trapped ions having said given charge-to-mass ratio as a function of reaction time.

Claim 12

Dependent Claim 139 words

A spectroscopy method of analyzing a sample comprising, ionizing a sample within an analyzer cell during an ionizing period, trapping substantially all ions of a given charge sign formed within the analyzer cell, causing them to move orbitally at an angular frequency by subjecting the ions to the combined action of static electric fields and a magnetic field, after a reaction time delay period following the ionizing period, bringing ions of a given charge-to-mass ratio and an oscillating electric field applied transversely to the lines of force of the magnetic field into resonance for resonance detection of said ions during a detection time period, said oscillating electric field being non-resonant with all trapped ions at all times outside the detection time period, neutralizing the trapped ions after the detection time period, and repeating the cycle of steps defined above.

Claim 13

Dependent Claim 139 words

A spectroscopy method of analyzing a sample comprising, ionizing a sample within an analyzer cell during an ionizing period, trapping substantially all ions of a given charge sign formed within the analyzer cell, causing them to move orbitally at an angular frequency by subjecting the ions to the combined action of static electric fields and a magnetic field, after a reaction time delay period following the ionizing period, bringing ions of a given charge-to-mass ratio and an oscillating electric field applied transversely to the lines of force of the magnetic field into resonance for resonance detection of said ions during a detection time period, said oscillating electric field being non-resonant with all trapped ions at all times outside the detection time period, neutralizing the trapped ions after the detection time period, and repeating the cycle of steps defined above.

Claim 14

Dependent Claim 84 words

The spectroscopy method as defined in claim 11, which includes, exciting a group of trapped ions at their resonant frequency by subjecting them to an irradiating pulse comprising a pulsed oscillating electric field applied transversely to the lines of force of the magnetic field during an irradiating pulse pEriod occurring during a portion of the reaction time delay period prior to the detection time period to impart high kinetic energy to said group of trapped ions, which ions remain trapped within the analyzer cell.

Claim 15

Dependent Claim 92 words

The spectroscopy method as defined in claim 9 wherein, ion species of different charge-to-mass ratio are formed by ion-molecule reaction during the irradiating pulse period dependent upon the magnitude and duration of the irradiating pulse and are trapped in the analyzer cell, ions of one said species of different charge-to-mass ratio being detected during the detection time period, the method also including, scanning the reaction time delay period during succeeding cycles of operation for determination of the concentration of detected resonant ions of said one species as a function of reaction time.

Claim 16

Dependent Claim 39 words

The spectroscopy method as defined in claim 12 wherein the group of ions irradiated at their resonant frequency during the irradiating pulse period comprise the ions of a given charge-to-mass ratio which are detected during the detection time period.

Claim 17

Dependent Claim 37 words

The spectroscopy method as defined in claim 12 wherein the group of ion irradiated at their resonant frequency comprise ions having a charge-to-mass ratio different from the charge-to-mass ratio of ions detected during the detection time period.

Claim 18

Dependent Claim 84 words

The spectroscopy method as defined in claim 11 which includes, increasing during the initial portion of the reaction time delay period the kinetic energy of a group of the trapped ions by a known amount by exciting said group of ions at their resonant frequency with an oscillating electric field pulse of known duration and magnitude applied transversely to the lines of force of the magnetic field, which ions of increased kinetic energy remain trapped in the analyzer cell through the detection time period.

Claim 19

Dependent Claim 34 words

The spectroscopy method as defined in claim 11 including, scanning the reaction time delay period during succeeding cycles of operation for determination of the concentration of resonant ions as a function of reaction time.

Claim 20

Dependent Claim 21 words

The spectroscopy method as defined in claim 11 wherein the method is performed within a single region of an analyzer cell.

Claim 21

Dependent Claim 150 words

A spectroscopy method comprising, ionizing a sample within one region of an analyzer cell, trapping substantially all ions of a given charge sign within said one region of the cell, causing them to move orbitally at angular frequencies dependent upon the charge-to-mass ratio of said ions by subjecting them to a unidirectional magnetic field and a plurality of static electric fields, during a reaction time period, subjecting the trapped ionized sample to an oscillating electric field applied transversely to the lines of force of the magnetic field at a frequency removed from the angular frequency of all orbiting ions, by step operation, following the reaction time period, bringing ions having a given charge-to-mass ratio and said oscillating electric field into resonance during a detection time period for determination of the concentration of the resonant ions, and neutralizing all of the ions within the analyzer cell after the detection time period.

Claim 22

Dependent Claim 150 words

A spectroscopy method comprising, ionizing a sample within one region of an analyzer cell, trapping substantially all ions of a given charge sign within said one region of the cell, causing them to move orbitally at angular frequencies dependent upon the charge-to-mass ratio of said ions by subjecting them to a unidirectional magnetic field and a plurality of static electric fields, during a reaction time period, subjecting the trapped ionized sample to an oscillating electric field applied transversely to the lines of force of the magnetic field at a frequency removed from the angular frequency of all orbiting ions, by step operation, following the reaction time period, bringing ions having a given charge-to-mass ratio and said oscillating electric field into resonance during a detection time period for determination of the concentration of the resonant ions, and neutralizing all of the ions within the analyzer cell after the detection time period.

Claim 23

Dependent Claim 185 words

A spectrometer comprising, a closed chamber to which a gas sample may be admitted, an analyzer cell within the chamber, means for ionizing a gas sample admitted to the chamber during an ionizing period, means for producing a magnetic field across the analyzer cell for causing substantially all ions of a given charge sign within the cell to move orbitally at angular frequencies dependent upon their charge-to-mass ratio, trapping potential means applied to the analyzer cell for trapping the orbitally moving ions therewithin, means for producing a first oscillating electric field across the analyzer cell transverse to the magnetic field, which oscillating electric field is non-resonant with any trapped ions, pulsed frequency shift means for bringing certain trapped ions having a given charge-to-mass ratio and said oscillating field into resonance only during a detection pulse period following a reaction time delay period whereby said resonant ions absorb energy from the oscillating field during said detection pulse period, means for sensing such energy absorption only during said detection pulse period, and means for neutralizing all of the ions within the cell after the detection pulse period.

Claim 24

Dependent Claim 185 words

A spectrometer comprising, a closed chamber to which a gas sample may be admitted, an analyzer cell within the chamber, means for ionizing a gas sample admitted to the chamber during an ionizing period, means for producing a magnetic field across the analyzer cell for causing substantially all ions of a given charge sign within the cell to move orbitally at angular frequencies dependent upon their charge-to-mass ratio, trapping potential means applied to the analyzer cell for trapping the orbitally moving ions therewithin, means for producing a first oscillating electric field across the analyzer cell transverse to the magnetic field, which oscillating electric field is non-resonant with any trapped ions, pulsed frequency shift means for bringing certain trapped ions having a given charge-to-mass ratio and said oscillating field into resonance only during a detection pulse period following a reaction time delay period whereby said resonant ions absorb energy from the oscillating field during said detection pulse period, means for sensing such energy absorption only during said detection pulse period, and means for neutralizing all of the ions within the cell after the detection pulse period.

Claim 25

Dependent Claim 57 words

The spectrometer as defined in claim 20 wherein said pulsed frequency shift means for bringing certain of said trapped ions and said oscillating field into resonance comprises means for pulse changing the trapping potential means during the detection pulse period to change the angular frequency of said certain ions to the frequency of the oscillating electric field.

Claim 26

Dependent Claim 76 words

The spectrometer as defined in claim 20 including, means for producing a second oscillating electric field across the analyzer cell transverse to the magnetic field for exciting ion cyclotron resonance of an ion species within the cell during an irradiating period during the initial portion of the reaction time period following the ionizing period and preceding the detection period to produce by ion-molecule reaction another species of ions which also are trapped within the analyzer cell.

Claim 27

Dependent Claim 181 words

An ion trap for use in a spectrometer or the like comprising, an evacuable chamber to which a gas sample can be admitted, an analyzer cell having at least 6 spaced electrodes disposed within said chamber including, (1) first and second electrodes forming first opposite sides, (2) third and fourth electrodes forming second opposite sides, and (3) fifth and sixth electrodes forming third opposite sides, means for ionizing a gas sample admitted to the chamber within the cell, means for producing a magnetic field across the cell for causing the ions within the cell to move orbitally, the magnetic lines of force extending through said first and second electrodes and generally parallel with said third, fourth, fifth, and sixth electrodes, and a d-c potential source of one polarity connected to said first and second electrodes and a d-c potential source of opposite polarity connected to said third, fourth, fifth and sixth electrodes for producing static electric fields between the electrodes whereby orbiting ions having a charge sign of the polarity of said first and second electrodes are trapped within the cell.

Claim 28

Dependent Claim 181 words

An ion trap for use in a spectrometer or the like comprising, an evacuable chamber to which a gas sample can be admitted, an analyzer cell having at least 6 spaced electrodes disposed within said chamber including, (1) first and second electrodes forming first opposite sides, (2) third and fourth electrodes forming second opposite sides, and (3) fifth and sixth electrodes forming third opposite sides, means for ionizing a gas sample admitted to the chamber within the cell, means for producing a magnetic field across the cell for causing the ions within the cell to move orbitally, the magnetic lines of force extending through said first and second electrodes and generally parallel with said third, fourth, fifth, and sixth electrodes, and a d-c potential source of one polarity connected to said first and second electrodes and a d-c potential source of opposite polarity connected to said third, fourth, fifth and sixth electrodes for producing static electric fields between the electrodes whereby orbiting ions having a charge sign of the polarity of said first and second electrodes are trapped within the cell.

Claim 29

Dependent Claim 37 words

The ion trap as defined in claim 23 including, means for applying a radio frequency potential across said third and fourth electrodes for the excitation and detection of cyclotron resonance of trapped ions of a given species.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1976-06-25	1976-12-25	1977-06-26	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1980-06-25	1980-12-25	1981-06-26	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1984-06-25	1984-12-25	1985-06-26	$7700.00	Window Closed / Lapsed

Method and apparatus for pulsed ion cyclotron resonance spectroscopy

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