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Publication numberUS2836750 A
Publication typeGrant
Publication dateMay 27, 1958
Filing dateJan 6, 1956
Priority dateJan 7, 1955
Publication numberUS 2836750 A, US 2836750A, US-A-2836750, US2836750 A, US2836750A
InventorsKarl Weimer
Original AssigneeLicentia Gmbh
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Ion source
US 2836750 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

K. WEIMER May 27, 1958 ION SOURCE Filed Jan. 6, 1956 7 5 7 2 6 I m 2 a I 2 l h A I 80 3 I 2 w Z 3 a 8 m iii; llll ll Tr. m m r lg 2 Inventor? KARL WE/MER 7 O v m :5 mm 2 .64 I n. w 2 :1. I I2 "a I I xr/xu/ 6 I w 9 z a k x v l all I 0 F I1- be 5 w W E I Affameys United States Patent 2,836,750 ION SOURCE Karl Weimer, Gottingen, Germany, assignor to Licentia- Patent-Verwaltungs G. m. b. 1%., Hamburg, Germany Application January 6, 1956, Serial No. 557,773 Claims priority, application Germany January 7, 1955 12 Claims. (Cl. 313-63) This invention relates to an ion source. It relates more particularly to a novel type of an ion source for ionizing gaseous particles.

It is already known in the art to ionize gaseous particles by means of electrons, for instance, those generated by the high frequency field of a high frequency coil or emitted from a cathode.

In order to achieve a pressure difference between the ionization chamber of the ion source and a space provided for accelerating the ions, the hitherto known sources require a narrow channel between the ionization chamber and the above mentioned space, which channel reduces the yield of the ionic source by restricting the beam of the ionic particles.

it is an object of my invention to provide a new ion source with a high yield.

This object is achieved in the ion source according to my invention which source is characterized by the ionization of a stream of gaseous particles travelling in an evacuated chamber with a high and preferably supersonic velocity.

According to a further feature of my invention 1 provide, in an ion source, a Laval nozzle capable of producing a jet of gaseous particles of supersonic speed.

According to yet another feature of the invention I provide for an adjustment of a gaseous stream in an ion source in such a manner as to cause the development of standing shock waves in said gaseous beam. Thereby I attain the formation of wave nodes in the gaseous beam which fact permits an effective ionization of the gaseous particles in the nodes of the standing shock waves.

The high density of gaseous particles in the supersonic jet and, in particular, due to the formation of a standing shock wave, in the nodes of the latter, facilitates ionization of the particles, and consequently leads to a higher yield of ionized particles than can be attained with the known devices.

in a preferred embodiment of the invention as hereinafter more fully described, the ion source comprises an evacuated chamber to which pumping means are connected. A stream of gaseous particles is introduced into this evacuated chamber as a supersonic jet. In the chamber, the gaseous particles are ionized preferably in a node of a standing shock wave formed by the supersonic jet and separated from the remaining unionized gaseous stream.

The ionized particles are guided to outlet means, which may, for instance, be connected to known means for the separation of isotopes.

It is preferred to provide magnetic fields to separate the ionized particles from the gaseous beam.

in a further preferred embodiment, electric fields are provided for separating the ionized particles from the gaseous beam.

In a particularly advantageous embodiment of the invention, the stream of gaseous particles is introduced with supersonic velocity into the chamber of the ion source and directed on to an opening for pumping means, so that a high vacuum is maintained in the chamber and the gaseous beam is concentrated to occupy only a small part of the chamber.

The injection of gaseous particles at supersonic speed into a chamber, for instance through a Laval nozzle,

limits the width of the gaseous particle jet, since the velocity component of the particles in the direction of the jet is greater than the component transverse to said jet, which latter component depends on the diffusion velocity of the gaseous particles over the entire volume of the chamber.

In the known devices, in which gas is caused to flow into an ionization chamber by means of a smaller pressure difference corresponding to a particle velocity below the speed of sound, the pressure prevailing in the chamber is practically uniform.

The supersonic injection of gaseous particles according to the invention offers the important advantage that the conventionally required special means for the restriction of particle flow in the ionization chamber and/ or a subsequent acceleration of the ionized particles in the isotope separator can be dispensed with.

The ion source according to my invention permits to attain a much higher yield of ionized particles than the known ion sources, and, nevertheless, practically eliminates the undesirable penetration of unionized particles into that part of the device through which the ionized particles are emitted from the source.

The aforesaid objects and advantages will be better understood at the hand of the detailed description following hereinafter in connection with Figures 1 and 2 of the accompanying drawings wherein Figure l is a schematic sectional view of an ion source according to the invention provided with a supersonic jet nozzle and a high frequency coil and other accessories according to the invention.

Figure 2 is another schematic sectional view provided with an electron gun for ionizing the gaseous particles which are introduced into the evacuated chamber with supersonic velocity.

Referring now to the drawings it will be seen that the ion source comprises an evacuated chamber 1 having a supersonic jet nozzle, preferably a Laval nozzle, 2. A stream 3 of gaseous particles enters the evacuated chamber 1 with supersonic velocity through the supersonic jet nozzle 2. The stream 3 of gaseous particles is provided from a stock bottle (not shown), which is connected with supersonic jet nozzle 2 by means of a pipe and a throttle (not shown). According to its high velocity the beam 3 of gaseous particles remains concentrated over a relatively long distance. An opening 4 is provided in the evacuated chamber 1 which opening is located opposite the opening 4 which latter is connected via a pipe 7 to a pump 5. Hollow vessels 18 combined with the wall parts 6 of the chamber 1 and the part 7:: of the pipe 7 between the opening 4 and the pump 5 are preferably provided for containing cooling media so that a high vacuum in the chamber it is maintained. Between the wall parts 6 and the adjacent wall parts so of the chamber 1, on the one hand, between pipe parts 7a and the remaining part of pipe 7 leading to the pump 5, intermediate pieces 12 are arranged for therrnic insulation.

As an example in the Figures 1 and 2 an adjustment of the gaseous beam is shown which leads to the formation of shock waves resembling a standing wave.

In order to obtain a high rate of ionization the ionizing means are arranged in the neighborhood of a node 8 of particle stream 3. For instance in Figure 1 a high frequency coil 9, and in Figure 2 an electron beam 15, are provided for ionization. The electron beam 15' is generated by an electron source 16 and directed through a node 8 on to a target 17 which latter is at a desired potential.

The beam 13 of ionized particles is separated from the beam 3 of gaseous particles by means of a magnetic field and preferably guided by the same field through 'too narrow'an opening 10. This advantage can preferably be achieved by ionizing gaseous particles in a concentrated gaseousbeam in such a manner that already in those parts of the chamber 1 adiacent to the opening 10, a relatively high vacuum is maintained.

It will be understood that this invention is susceptible to modification in order to adapt itto different usages and conditions, and, accordingly, it is desired to comprehend such modifications within this invention as may fall Withinthe scope'of the appended claims.

I claim: 3 1

l. Inan ion source comprising an evacuated chamber, pumping means connected with said evacuated chamber, means for introducing a stream of gaseousparticles in said evacuated chamber at supersonic speed, means for ionizing a portion of said gaseous particles, means for separating the ionized portion of said particles from said stream of gaseous particles, and outlet means for said ionized particles.

2. In an ion source comprising an evacuated chamber, pumping means connected with said evacuated chamber, jet producing means for introducing a stream of gaseous particles in said evacuated chamber, which stream leaves said jet producing means with supersonic velocity and develops a standing shock wave in said chamber, means for ionizing a portion of said particles, means for sepa rating the ionized particles from" said stream of gaseous particles, and outlet means for said ionized particles.

7 3. In an ion source comprising an evacuated chamber, jet producing means for introducing a stream of gaseous particles in said evacuated chamber, which stream leaves jet'with supersonic velocity, means for ionizing a portion of said particles, means for separating the ionized particles from said stream of gaseous particles, pumping means for removing said gaseous particles from said evacuated chamber, said evacuated chamber havingan opening opposite said jet producing means, to which opening said pumping means are connected, whereby said stream of gaseous particles is directed toward said'opening, and

outlet means for said ionized particles.

4. In an ion' source comprising anevacuated chamber,

.jet producing means for introducing a stream of gaseous particles in said evacuated chamber, said stream leaving said jet producing means with supersonic velocity, means for ionizing a portion of said particles, means for separating the ionized particles from said stream of gaseous particlesppumping means for removing the remaining gaseous particles fromsaid evacuated chamber, the open- 7 ing for said'pumping means being arranged opposite to said jet producing means, cooling means arranged adiacent to said opening for. said pumping means, and outlet means for said ionized particles, disposed at an angle to said stream ofgaseous particles. g V

5. In an ion source comprising an evacuated chamber, pumping means connected withisaid evacuated chamber,

' means for introducing a stream of gaseous particles with supersonic velocity into said evacuated chamber so as to form a standing shock wave therein, means for ionizing a portion of said particles, said ionizing means being arranged so that the ionization of said gaseous particles takes place inat least one nodeof said standing shock Wave of gaseous particles, means for separating the ionized particles from said stream of gaseous particles, and outlet means for said ionized. particles.

, 6. In an ion sourcccomprising an evacuated chamber.

pumping means connected with said evacuated chamber,

means for introducing a stream of gaseous particles with pumping means connected with said evacuated chamber, means for introducing a stream of gaseous particlesvvith supersonic velocity in said evacuated chamber, high fro-- quen'cy coil means, said gaseous particles traversing said high frequency coil means and a portion of said particles being ionized by the high frequency field of said high frequency coil means, means for separating the ionized particles from said stream of gaseous particles, and outlet means for said'ionized particles. I I

V 8. In an ion source comprising an evacuated'chamber, pumping means'connected with said evacuated chamber, means for introducing a stream of gaseous particles with supersonic velocity in said evacuated chamber, means for generating and accelerating electrons, said electrons being directed onto said stream of gaseous particles for ionizing a portion of said gaseous particles, means for separating the ionized particles from said stream of gaseous particles, and outlet means for said ionized particles.

9. In an ion source comprising an evacuated chamber, pumping means connected With said evacuated chamber, means for introducing a stream of gaseous particles with supersonic velocity in said evacuated chamber, means for ionizing a portion. of said particles, electric means" for separating the ionized particles from said stream of gaseous particles, and outlet means for said ionized particles. p I a 10, In an ion source comprising an evacuated chamber,

pumping means connected with said evacuated chamber,

means for introducing a stream of gaseous particles with supersonic velocity in said evacuated chamber, means for ionizing aportion of said particles, magnetic means for separating the ionized particles from said stream of gase- 1 ous particles, and outlet means for said ionized particles; 11. In an ion source comprising an evacuated chamber, pumping means connected With'said evacuated chamber,

means for introducinga stream of gaseous particles with supersonic velocity in said evacuated chamber, meansfor ionizing a portion of said particles, means for separating the ionized particles from said stream of gaseous particles, and outlet meansfor said ionized particles, said outlet means being connected with means for separation of isotopes. g V

12. In an ion sourcecomprising-an evacuated chamber .a Laval nozzle for introducing a stream of gaseous particles with supersonic velocity into said evacuated'cham- .ber'in order, to develop a standing shock wave having at least one node therein, said chamber having an opening opposite said Laval jet, pumping means connected with said opening, said stream of gaseous particles being concentrated to. occupy only a small part of said chamber and being directed toward said opening, means for ioniz- 7 ing a portion of said particles and comprising a high frequency coil disposed in the region of a nodeof said shock Wave, said coil being adapted to generate a high frequency field which ionizes said gaseous particles in said node, magnetic means for separating the ionized particles from said stream of gaseous particles, and outlet means for said ionized particles, saidoutlet means being disposed substantially at a right angle to the direction of said stream of gaseous particles from said Laval nozzle to said opening, and permitting an unobstructed flow of said ionized particles from said chamber to the outside References Cited in the file of this patent UNITED STATES PATENTS 2,400,557 Lawlor Ma 21, 1946 2,582,215 Koppius Jan; 15,1952 2,633,539

Altar Mar. 31, -4=

Patent Citations
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US2582216 *Oct 16, 1946Jan 15, 1952Philips Lab IncMass spectrometer
US2633539 *Jan 14, 1948Mar 31, 1953Altar WilliamDevice for separating particles of different masses
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2919370 *Oct 28, 1958Dec 29, 1959Plasmadyne CorpElectrodeless plasma torch and method
US2969480 *Apr 29, 1959Jan 24, 1961Commissariat Energie AtomiqueIon sources
US2977495 *Jun 3, 1959Mar 28, 1961Commissariat Energie AtomiqueIon source
US3015745 *Sep 16, 1959Jan 2, 1962Commissariat Energie AtomiqueApparatus for ionising a gas to obtain high intensity pulsed ions or electrons
US3084281 *Nov 30, 1956Apr 2, 1963Mills Carroll BIon source
US3116433 *Jun 15, 1959Dec 31, 1963Giannini Controls CorpProduction of neutral molecular beams
US3230693 *Jun 22, 1962Jan 25, 1966Siemens AgApparatus for mass separation of reactive gases
US3271556 *Oct 31, 1963Sep 6, 1966Lockheed Aircraft CorpAtmospheric charged particle beam welding
US3272983 *Jan 10, 1964Sep 13, 1966Veach Allen MIon-producing mechanism for calutrons
US3277631 *Nov 5, 1963Oct 11, 1966Soudure Electr AutogeneProcess and apparatus for separation of a gas mixture
US3331978 *May 28, 1962Jul 18, 1967Varian AssociatesElectron beam x-ray generator with movable, fluid-cooled target
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US3496701 *Dec 13, 1967Feb 24, 1970Berg T G OweMethod and apparatus for removing particulates from flowing gases
US3502863 *Aug 2, 1967Mar 24, 1970Hitachi LtdElectron bombardment type ion source with permanent magnet focusing means therein
US3505518 *Dec 27, 1966Apr 7, 1970Hitachi LtdIon sources for mass spectrometers
US3558877 *Dec 19, 1966Jan 26, 1971Gca CorpMethod and apparatus for mass separation by selective light absorption
US3974380 *Jan 17, 1975Aug 10, 1976Balzers Patent-Und Beteiligungs AgMass spectrometer
US4024217 *May 23, 1975May 17, 1977The United States Of America As Represented By The United States Energy Research And Development AdministrationMethod of isotope separation by chemi-ionization
US4071334 *Aug 7, 1975Jan 31, 1978Maxwell Laboratories, Inc.Electrostatic precipitators
US4081674 *Dec 20, 1976Mar 28, 1978Hitachi, Ltd.Ion microprobe analyzer
US4115078 *May 21, 1975Sep 19, 1978Kraftwerk Union AktiengesellschaftLaser or maser beams
US4213043 *Jul 20, 1977Jul 15, 1980Trw Inc.Method for flowing a large volume of plasma through an excitation region
US8680460 *Dec 30, 2008Mar 25, 2014Agilent Technologies, Inc.Converging-diverging supersonic shock disruptor for fluid nebulization and drop fragmentation
Classifications
U.S. Classification96/1, 250/288, 250/427, 313/163, 313/362.1
International ClassificationH01J49/10
Cooperative ClassificationH01J49/10
European ClassificationH01J49/10