US3086110A - Mass spectrometer - Google Patents

Mass spectrometer Download PDF

Info

Publication number
US3086110A
US3086110A US796626A US79662659A US3086110A US 3086110 A US3086110 A US 3086110A US 796626 A US796626 A US 796626A US 79662659 A US79662659 A US 79662659A US 3086110 A US3086110 A US 3086110A
Authority
US
United States
Prior art keywords
plates
frequency
field
ions
electrode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US796626A
Other languages
English (en)
Inventor
Klopfer Anton Martin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
US Philips Corp
North American Philips Co Inc
Original Assignee
US Philips Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US3086110A publication Critical patent/US3086110A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J49/00—Particle spectrometers or separator tubes
    • H01J49/26—Mass spectrometers or separator tubes
    • H01J49/34—Dynamic spectrometers
    • H01J49/36—Radio frequency spectrometers, e.g. Bennett-type spectrometers, Redhead-type spectrometers
    • H01J49/38—Omegatrons ; using ion cyclotron resonance

Definitions

  • This invention relates to mass spectrometers for gases at low pressures in which a beam of electrons is shot in the direction of a static homogeneous magnetic field between two relatively parallel and electrically connected plates, an electric high-frequency iield being produced in the space between said plates, at right angles to the magnetic field, between two likewise parallel plates, annular intermediate electrodes being provided for homogenising the high-frequency field and adjacent one high-frequency electrode a collector being arranged for such ions as describe paths of increasing radius by the action of the various fields.
  • the high-frequency plates are collectors. Between these plates there ⁇ also exists a weak static field which serves to deflect non-resonant ions at right angles to the direction of the magnetic field and of the electric high-frequency field. If desired the two high-frequency plates may be connected separately to negative voltages with respect to the field-distribution rings.
  • one of the field distribution electrodes serves also as a collector for the resonant ions.
  • a construction which has no -tield distribution rings, but in which the two plates between which the beam of electrons is accelerated, together with two plates at right angles thereto, embrace the high-frequency space. In certain cases, these four plates have applied to them a common negative voltage less than 1 volt with respect to the high-frequency plates (on account of sensitivity variations of the omegatron).
  • the collector is constituted by a strip parallel to the high-frequency plates, the strip being either situated between the field distribution rings, or introduced into a slot in a side plate. rIhe electrodes ernbracing the high-frequency space are at a weakly positive potential with respect to the high-frequency plates.
  • An object of the invention is to provide an improvement which allows of reproducible measurements.
  • ln a mass spectrometer for gases of low pressure, in which a beam of electrons is shot in the direction of a statical homogeneous magnetic eld between two relatively parallel and electrically connected plates, in which an electric high-frequency field is produced in the space between these plates, at right angles to the magnetic field, between two likewise parallel plates, in which annular intermediate electrodes are provided for homogenising the high-frequency field and in which adjacent one high-frequency electrode a collector is arranged for such ions as describe paths of increasing radius by the action of the various fields, and in which the electrodes embracing the high-frequency space have applied -to them a weakly positive potential wtih respect to the 4high-fre- 3,086,l l0 Patented Apr.
  • ICC quency plates according to the invention two relatively parallel plates are arranged parallel -to the direction of the magnetic field and at right angles to the field-distribution rings adjacent the ends of these rings, said plates having applied to them a negative voltage of several -tens of volts with respect to the high-frequency plates so that the tiow of ions towards the collector isa maximum for both light and heavy ions.
  • the present invention builds further upon the recognition that a positive electrostatic field between the high-frequency plates and the field-distribution rings, possibly the plates through which the beam of electrons enters and emerges, facilitates a movement of ions towards the collector in planes parallel to the direction of the magnetic field, whereas this field causes ions to move towards the other electrodes in planes at right angles to the magnetic field.
  • the last-mentioned unfavorable iield is not only lavoided due to the two side-plates being at negative potential, but also the ions are assisted in their movement towards the collector, so that interfering effects, such as gas layers and electric charges of the electrodes, cannot substantially influence the paths of the ions.
  • FIGS. l 4to 3 show three mutually perpendicular crosssections of a mass spectrometer according to the invention
  • FIGS. 4 and 5 show its circuit diagrams and FIG. i6 shows the relative liow of ions towards the collector ⁇ as a function of a negative voltage on the side plates, that is to say for ions of two different masses.
  • the bulb of the -mass spectrometer is indicated by 1.
  • a plurality of current-supply wires are ⁇ arranged in the base of bulb 1.
  • the electrode system is built up on these lead-through wires with the aid of wire supports.
  • the base has a tubular extension 2 in which the current-supply wire for the collector extends.
  • the cathode filament, indicated by 3 is arranged inside a screen electrode 4 having an aperture for the beam of electrons.
  • An accelerating and focusing electrode 5 is arranged in front of the aperture in screen 4.
  • the two plates 6 ⁇ provided with apertures for passage of the electron beam are connected to one high-frequency plate 7, the other high-frequency plate bearing the number 8i.
  • the plate 7 has a narrow aperture 9 through which a collector 10 is passed.
  • the current-supply wire 11 for collector 10 is surrounded by a screen structure 13.
  • the field-distribution rings which are in total four in the figure, but may alternatively be six or eight in number, are indicated by 12.
  • a collector 14 for the electrons is .arranged behind one of the plates 6.
  • the side plates according to the invention bear the number 15.
  • a tube leads from the bulb to the apparatus from the contents of which the composition of the gas is to be determined.
  • Plate S has dimensions of 25 by l5 mms.
  • the electrodes consist of gold sheet of 0.3 mm. thick. lf desired, it is possible to use gold-plated constantan or platinum or a platinum alloy. If the mass spectrometer can be sufficiently protected against oxidation, constantan is also permissible as the electrode material.
  • reference numeral 21 indicates the heatingcurrent battery for -the cathode and 21 indicates the battery for the accelerating voltage.
  • the battery 23 applies to the electrode 5 a positive voltage of about 10 volts with respect to the electrode 6.
  • the electrodes 4 and 5, when suitably connected, may be used for stabilising the flow of electrons.
  • the battery 22 has a voltage of about )y volts.
  • the collector-electrode 14 receives, with the aid of ⁇ a battery 24 and a potentiometer 25, a positive voltage of at most about 40 volts with respect to the electrode 6.
  • the high-frequency voltage is applied to a terminal 26.
  • the maximum effective high-frequency voltage is 1 volt and the frequency lies between 8 mc./Sec. and 30 kc./sec. for the masses of from 1 to 260.
  • the magnetic eld has a strength of 5,000 gauss.
  • the tield-distribution rings 12 are coupled by means of resistors 27 each of 200 ⁇ ohms and capacitors 23 each of 1 nf. in a high-frequency manner to the plates i and 8.
  • resistors 27 each of 200 ⁇ ohms and capacitors 23 each of 1 nf. in a high-frequency manner to the plates i and 8.
  • the rings 12 receive a positive voltage of at most 1 volt with respect to the plates 7 and 8.
  • a battery 31 and a potentiometer 32 impose on the plates 1S a negative voltage of at most 200 volts with respect to the electrodes 7 and 8.
  • FIG. 6 shows the relative flow of ions z'+/i+max towards the collector for the gases nitrogen and hydrogen as a function of the negative voltage V15 on the electrode 15 at a pressure of 4.1041 mm. of Hg with otherwise optimum conditions for a mass spectrometer having 6 field-distribution rings. It will readily be evident that a rather high negative voltage on the electrodes 15 is required for both the light and the heavy ions. The value of the voltage is, of course, dependent upon the distance between these electrodes and the field-distribution rings, upon the dimensions and the number of these rings.
  • a beam of electrons is drawn from cathode 3 through holes in shield 4, electrode 5 and rst electrode 6 in the space between high-frequency electrodes 8, 9 and eld rings 12. The electron beam ionizes the gas present in enclosure 1. The beam of electrons is collected through a hole in second electrode 6 on a collector electrode 14.
  • the ions formed come under the influence of the highfrequency eld between electrodes 8 and 9.
  • the ions Due to the presence of the magnetic field H, the ions obtain movements perpendicular to the magnetic eld H. For certain ions for which the motion in the field corresponds to the frequency of the high-frequency field the movement is in spirals of increasing radius such as is known in the arrangements of the known art. Ultimately these ions are collected on collector electrode v110. By varying the ⁇ frequency of the high-frequency eld, ions of different mass can be collected.
  • a mass spectrometer for a gas at low pressures comprising means including a source of electrons and an accelerating electrode to project a beam of electrons into a gas in a given direction between a pair of spaced, rcla tively parallel, electrically connected plates; means to produce a static, homogeneous magnetic ⁇ lield between the plates in the same direction as said given direction; means to produce a high-frequency electric field between a second pair of plates in a direction perpendicular to the direction of the magnetic iicld; a plurality of annular electrodes disposed between the latter plates for homogenizing the high-frequency electric field; a co1- lector electrode disposed adjacent to one of said plates for the high-frequency electric eld to collect ions whose .paths have an increasing radius when subject to said field; means to apply a positive potential to the accelerating electrode relative to the electrodes enclosing the space; a pair of relatively parallel plates disposed parallel to the direction of the magnetic field adjacent to the ends of and at right

Landscapes

  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
  • Electron Tubes For Measurement (AREA)
US796626A 1958-03-15 1959-03-02 Mass spectrometer Expired - Lifetime US3086110A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEN14808A DE1136510B (de) 1958-03-15 1958-03-15 Massenspektrometer, in welchem die Ionen Spiralbahnen beschreiben

Publications (1)

Publication Number Publication Date
US3086110A true US3086110A (en) 1963-04-16

Family

ID=7339937

Family Applications (1)

Application Number Title Priority Date Filing Date
US796626A Expired - Lifetime US3086110A (en) 1958-03-15 1959-03-02 Mass spectrometer

Country Status (6)

Country Link
US (1) US3086110A (de)
CH (1) CH369298A (de)
DE (1) DE1136510B (de)
FR (1) FR1228330A (de)
GB (1) GB918693A (de)
NL (1) NL109528C (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3842267A (en) * 1972-02-09 1974-10-15 Battelle Development Corp Method and apparatus for measuring, by ionization, the flux of vapour emitted during vacuum vaporization
US4208582A (en) * 1977-12-05 1980-06-17 Trw Inc. Isotope separation apparatus

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2629055A (en) * 1950-06-22 1953-02-17 Cons Eng Corp Mass spectrometry
US2698389A (en) * 1953-07-20 1954-12-28 Gen Electric Radio frequency mass spectrometer
US2798956A (en) * 1954-06-09 1957-07-09 Exxon Research Engineering Co Ion resonance mass spectrometer
US2806955A (en) * 1946-05-11 1957-09-17 Gen Electric Mass spectrometer
US2868986A (en) * 1954-06-08 1959-01-13 Exxon Research Engineering Co Ion resonance mass spectrometer

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2632111A (en) * 1950-08-03 1953-03-17 Cons Eng Corp Mass spectrometry

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2806955A (en) * 1946-05-11 1957-09-17 Gen Electric Mass spectrometer
US2629055A (en) * 1950-06-22 1953-02-17 Cons Eng Corp Mass spectrometry
US2698389A (en) * 1953-07-20 1954-12-28 Gen Electric Radio frequency mass spectrometer
US2868986A (en) * 1954-06-08 1959-01-13 Exxon Research Engineering Co Ion resonance mass spectrometer
US2798956A (en) * 1954-06-09 1957-07-09 Exxon Research Engineering Co Ion resonance mass spectrometer

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3842267A (en) * 1972-02-09 1974-10-15 Battelle Development Corp Method and apparatus for measuring, by ionization, the flux of vapour emitted during vacuum vaporization
US4208582A (en) * 1977-12-05 1980-06-17 Trw Inc. Isotope separation apparatus

Also Published As

Publication number Publication date
GB918693A (en) 1963-02-13
DE1136510B (de) 1962-09-13
NL109528C (de)
CH369298A (de) 1963-05-15
FR1228330A (fr) 1960-08-29

Similar Documents

Publication Publication Date Title
US3410997A (en) Multipole mass filter
US2975277A (en) Ion source
GB698850A (en) Improvements in and relating to apparatus for separating charged particles of different mass-to-charge ratios
GB1326279A (en) Mass spectrometers
US3939344A (en) Prefilter-ionizer apparatus for use with quadrupole type secondary-ion mass spectrometers
US3280326A (en) Mass filter with sheet electrodes on each side of the analyzer rod that intersect on the ion beam axis
US3461285A (en) Mass spectrometer ion source with a two region ionization chamber to minimize energy spreading of the ions
US3122631A (en) Apparatus for focusing a line type ion beam on a mass spectrometer analyzer
US3725700A (en) Multipole mass filter with artifact-reducing electrode structure
US3075076A (en) Gas-analyzing method and apparatus
US3197633A (en) Method and apparatus for separating ions of respectively different specific electric charges
US3086110A (en) Mass spectrometer
US3560734A (en) Quadrupole mass filter with fringing-field penetrating structure
US3678267A (en) Ion source comprising a concave-shaped repeller
US2845571A (en) Electrostatically focused traveling wave tube
US3371205A (en) Multipole mass filter with a pulsed ionizing electron beam
US3783279A (en) Hyperbolic field mass filter
US3501630A (en) Mass filter with removable auxiliary electrode
US2698389A (en) Radio frequency mass spectrometer
US3221164A (en) Ion source for mass filter wherein the electron and ion beam axes are the same
US3287589A (en) Electron-collision ion source, particularly for electric mass spectrometers
US3217161A (en) Electrode means to electrostatically focus ions separated by a mass spectrometer on a detector
GB898919A (en) Improvements in or relating to apparatus for determining the quantity of charged particles of predetermined mass present in a space
US2354122A (en) Vacuum tube
US3086111A (en) Mass spectrometer for gases at low pressures