US2930917A - Ion sources - Google Patents
Ion sources Download PDFInfo
- Publication number
- US2930917A US2930917A US716386A US71638658A US2930917A US 2930917 A US2930917 A US 2930917A US 716386 A US716386 A US 716386A US 71638658 A US71638658 A US 71638658A US 2930917 A US2930917 A US 2930917A
- Authority
- US
- United States
- Prior art keywords
- plate
- filament
- grid
- ions
- electrons
- 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
Links
- 239000000126 substance Substances 0.000 claims description 8
- 150000002500 ions Chemical class 0.000 description 43
- 239000001257 hydrogen Substances 0.000 description 5
- 229910052739 hydrogen Inorganic materials 0.000 description 5
- 230000000155 isotopic effect Effects 0.000 description 5
- 239000006185 dispersion Substances 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- 238000010884 ion-beam technique Methods 0.000 description 3
- 125000004429 atom Chemical group 0.000 description 2
- 238000005421 electrostatic potential Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- 150000002431 hydrogen Chemical class 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000009897 systematic effect Effects 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 1
- YZCKVEUIGOORGS-OUBTZVSYSA-N Deuterium Chemical compound [2H] YZCKVEUIGOORGS-OUBTZVSYSA-N 0.000 description 1
- -1 H2+ ions Chemical class 0.000 description 1
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052805 deuterium Inorganic materials 0.000 description 1
- 230000005686 electrostatic field Effects 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 238000005381 potential energy Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J49/00—Particle spectrometers or separator tubes
- H01J49/02—Details
- H01J49/10—Ion sources; Ion guns
- H01J49/14—Ion sources; Ion guns using particle bombardment, e.g. ionisation chambers
- H01J49/147—Ion sources; Ion guns using particle bombardment, e.g. ionisation chambers with electrons, e.g. electron impact ionisation, electron attachment
Definitions
- the present invention relates to ion sources, and in particular to those intended to feed ions to a mass spectrometer in order to permit isotopic analysis of the element from which said ions have been obtained.
- the chief object of this invention is to simplify the structure of such sources and to make their output more abundant and more representative of the true isotopic nature of the element that is ionized, in particular when the atomic number of this element is low (hydrogen, helium).
- the ion source comprises means forming a chamber spaced apart from any magnetic tield and containing, under low pressure, a gaseous substance to be ionized and three electrodes 1ocated in said chamber, said electrodes being, respectively, a iilament'ffor the emission of electrons, a plate and an accelerating grid' interposed between said filament andV said plate.
- said filament is at a potential intermediate between that of said grid and that ⁇ of said plate, whereby the electrons issuing from said filament pass through said grid and then oscillate in the space between said grid and said plate where they form a kind of electron fog suitable for ionization of the particles of said substance by impact of the electrons thereon, means forming an electrostatic potential being provided to extract'the ions thus formed from said chamber.
- ⁇ the ions of the element to be studied are generally produced by the action of a beam of electrons directed onto a sarnple of ,said element.
- the impact of the electrons against the particles (atoms or molecules) of this element gives rise to the desired ions.
- the beam of ions thus produced is intended to feed a mass spectrometer in order to elect -the isotopic analysis of the ionized element, it is preferable not to use a magnetic field in order to fpcus the beam of'electrons because the presence of such a iield is a cause of complications.
- the substance to be ionized is introduced in the gaseous state in a space where the pressure is low, said space containing a filament capable of emitting electrons, a grid at a potential which is positive with respect to ,thatl of the filament in order'to accelerate these electrons and to cause them to ionize by impact the particles Y of said substance, and a plate provided with a hole orY any suitable perforation, said plate being at a potential which is both positive with respect to that of the filament and slightly negative with respect to that of the grid, whereby the electrons are collected by this plate and someof the ions that have been formed, which drop in aV rain-like fashion on said plate, pass through said holes ⁇ or perforations to form the desired beam'ofions.
- the outputV of such a source is limited by the fact that a great number of electrons are caught by the plate beforev giving rise to anion of the substance. Furthermore, among the ions that are formed, only those located opposite the holes or perforations of the perforations. i
- the values of the potentials of the re# pective electrodes are such .that the potential of the,Y v
- filament is negative with respect to the grid but positive with respect to the plate.
- the electrons emitted by the tilament are pulled toward the ,grid through which they iirst pass ,to be subsequently Apushed back by the plate, the energy they have acquired between the filament fand the grid being not sutiicient to enable them to lreach the plate.
- These Velectrons therefore oscillate between the plate and the grid, forming an electron fog in the region close to the grid. It is in this region that ionization of the gaseous molecules takes place.
- a fourth electrode In order to extract the Vions. formed in said fog, use is made of a fourth electrode provided with suitable perforations and highly biased.
- the source of ions thusr obtained is particularly well adapted to the case of analysis by means of a mass spectrometer of elements having a low atomic number.
- the only figure is a perspective diagrammatic view of an ion source according to this invention'.
- 1 designates the filament
- 2 the grid in the form of a conductor wound helically about ⁇ ilament
- 3 is the plate constituted by a semi-cylinder of revolution having its axis in coincidence with filament 1.
- Grid 2 being at the highest potential V2
- filament 1 is at a potential V1 intermediate between the potential V2 of grid 2 and the potential V3 of plate 3.
- Two flat elements S and 6 are at a potential (V5, V6) adjustable and close to that of plate 3.
- the gas-tight chamber which contains the gas to be ionized under low pressure is designated by the numeral 8.
- An interesting application of this ion source consists in isotopic analysis in a mass spectrometer of hydrogen containing a small amount of deuterium.
- filament 1 is a tungsten wire of a diameter equal to 0.2 mm. and of a length equal to 30 mm., located at a distance of 2S mm. from plate 4.
- Grid 2 is a helix of a pitch equal to 2 mm., constituted by a nickel wire of a diameter of 0.15 mm. wound on a cylinder of 5 mm. diameter and extending over a length of 28 mm.
- Plate 3 is made of stainless steel and has a diameter of l5 mm., a length of 25 mm. and a thickness of 0.6 mm.
- Slit 7 is a rectangle one millimeter wide and ten millimeters long.
- the focussing side elements 5 and 6 are constituted by two rectangular plates of 20 x 25 mm., at a distance of 17 mm. from each other.
- the potentials of the different electrodes are as follows:
- V1 2.500 volts
- V2 2.550 volts
- V3 2.490 volts
- the stream of electrons from filament 1 to grid 2 is ten milliamperes.
- This source also gives good results on a mass spectrometer for detecting helium leakages.
- An ion source which comprises means forming a chamber spaced apart from any magnetic field and containing, under low pressure, a gaseous substance to be ionized, at least three electrodes located in said chamber, said electrodes being, respectively, a ilament for the emission of electrons, a plate, and an accelerating grid interposed between said filament and said plate, said plate being at a potential lower than that of said filament and said filament being at a potential intermediate between that of said grid and that of said plate, whereby the electrons issuing from said filament pass through said grid and then oscillate in the space between said grid and said plate where they form a kind of electron fog suitable for ionization of the particles of said substance by impact of the electrons thereon, and means forming an electrostatic potential to extract the ions thus formed from said chamber.
- An ion source in which said means to extract the ions from said chamber include a fourth electrode at a potential highly negative with respect to that of said plate, said fourth electrode being provided with a slit for the passage of the ions extracted -from said chamber, said ion source further including side plates disposed symmetrically on opposed sides of said slit ⁇ for focussing an ion beam toward said slit.
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Electron Tubes For Measurement (AREA)
- Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
- Electron Sources, Ion Sources (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR346621X | 1957-02-23 |
Publications (1)
Publication Number | Publication Date |
---|---|
US2930917A true US2930917A (en) | 1960-03-29 |
Family
ID=8892471
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US716386A Expired - Lifetime US2930917A (en) | 1957-02-23 | 1958-02-20 | Ion sources |
Country Status (6)
Country | Link |
---|---|
US (1) | US2930917A (ja) |
BE (1) | BE564648A (ja) |
CH (1) | CH346621A (ja) |
DE (1) | DE1071853B (ja) |
GB (1) | GB877112A (ja) |
LU (1) | LU35771A1 (ja) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3313934A (en) * | 1963-02-19 | 1967-04-11 | Atlas Meb & Analysentechnik G | Field ion source for mass spectrometry with elongated emitter |
US3346735A (en) * | 1964-12-07 | 1967-10-10 | Dow Chemical Co | Electron source for mass spectrometers having an elongated filament and a concave focusing electrode with a resistive coating |
US3356843A (en) * | 1965-02-01 | 1967-12-05 | Gen Electric | Mass spectrometer electron beam ion source having means for focusing the electron beam |
US5523646A (en) * | 1994-08-17 | 1996-06-04 | Tucciarone; John F. | An arc chamber assembly for use in an ionization source |
US10217623B2 (en) | 2014-06-12 | 2019-02-26 | Micromass Uk Limited | Secondary electrospray ionization at reduced pressure |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2596580A1 (fr) * | 1986-03-26 | 1987-10-02 | Centre Nat Rech Scient | Generateur de plasma |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2495908A (en) * | 1948-07-16 | 1950-01-31 | Sylvania Electric Prod | Thermionic discharge device |
US2499320A (en) * | 1947-06-23 | 1950-02-28 | Loevinger Robert | Ion generator |
US2772364A (en) * | 1955-05-06 | 1956-11-27 | Cons Electrodynamics Corp | Mass spectrometry |
-
0
- DE DENDAT1071853D patent/DE1071853B/de active Pending
- BE BE564648D patent/BE564648A/xx unknown
- LU LU35771D patent/LU35771A1/xx unknown
-
1958
- 1958-02-10 CH CH346621D patent/CH346621A/fr unknown
- 1958-02-14 GB GB4944/58A patent/GB877112A/en not_active Expired
- 1958-02-20 US US716386A patent/US2930917A/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2499320A (en) * | 1947-06-23 | 1950-02-28 | Loevinger Robert | Ion generator |
US2495908A (en) * | 1948-07-16 | 1950-01-31 | Sylvania Electric Prod | Thermionic discharge device |
US2772364A (en) * | 1955-05-06 | 1956-11-27 | Cons Electrodynamics Corp | Mass spectrometry |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3313934A (en) * | 1963-02-19 | 1967-04-11 | Atlas Meb & Analysentechnik G | Field ion source for mass spectrometry with elongated emitter |
US3346735A (en) * | 1964-12-07 | 1967-10-10 | Dow Chemical Co | Electron source for mass spectrometers having an elongated filament and a concave focusing electrode with a resistive coating |
US3356843A (en) * | 1965-02-01 | 1967-12-05 | Gen Electric | Mass spectrometer electron beam ion source having means for focusing the electron beam |
US5523646A (en) * | 1994-08-17 | 1996-06-04 | Tucciarone; John F. | An arc chamber assembly for use in an ionization source |
US10217623B2 (en) | 2014-06-12 | 2019-02-26 | Micromass Uk Limited | Secondary electrospray ionization at reduced pressure |
Also Published As
Publication number | Publication date |
---|---|
LU35771A1 (ja) | |
GB877112A (en) | 1961-09-13 |
DE1071853B (ja) | |
BE564648A (ja) | |
CH346621A (fr) | 1960-05-31 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Inghram et al. | Surface ionization source using multiple filaments | |
Liebl | Ion microprobe analysers | |
Tate et al. | The dissociation of nitrogen and carbon monoxide by electron impact | |
Litherland | Fundamentals of accelerator mass spectrometry | |
US3576992A (en) | Time-of-flight mass spectrometer having both linear and curved drift regions whose energy dispersions with time are mutually compensatory | |
US2930917A (en) | Ion sources | |
JPH0378742B2 (ja) | ||
Moran et al. | Charge neutralization of He+ ion beams | |
US4943718A (en) | Mass spectrometer | |
US3769513A (en) | Ion kinetic energy spectrometer | |
US3122631A (en) | Apparatus for focusing a line type ion beam on a mass spectrometer analyzer | |
US2945951A (en) | Ion source and mass spectrometer utilizing same | |
Nier | Some reflections on the early days of mass spectrometry at the university of minnesota | |
Traeger | The development of electron ionization | |
US2563626A (en) | Ion source | |
Brunnée | New instrumentation in mass spectrometry | |
US2772363A (en) | Method and apparatus for ionization of solids | |
Melton | Ionization and Excitation Processes in Argon, Krypton, and the C2 Hydrocarbons Produced by Various Means | |
US2700107A (en) | Ion source | |
US3392280A (en) | Mass spectrometer utilizing an ion beam for ionizing the gas to be analyzed | |
Shiokawa et al. | Specific Features of Tohoku Charge Spectrometer | |
US3356843A (en) | Mass spectrometer electron beam ion source having means for focusing the electron beam | |
US3908123A (en) | Extraction electrode geometry for a calutron | |
GB1086959A (en) | Mass spectrometer gas analyzer instrument | |
US2894136A (en) | Ion source |