US3172597A - Ionic pump - Google Patents

Ionic pump Download PDF

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Publication number
US3172597A
US3172597A US122007A US12200761A US3172597A US 3172597 A US3172597 A US 3172597A US 122007 A US122007 A US 122007A US 12200761 A US12200761 A US 12200761A US 3172597 A US3172597 A US 3172597A
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United States
Prior art keywords
ferromagnetic
hollow cylinder
members
pump
magnet
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Expired - Lifetime
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US122007A
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English (en)
Inventor
Guyot Lucien
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.)
Compagnie Francaise Thomson Houston SA
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Compagnie Francaise Thomson Houston SA
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J41/00—Discharge tubes for measuring pressure of introduced gas or for detecting presence of gas; Discharge tubes for evacuation by diffusion of ions
    • H01J41/12—Discharge tubes for evacuating by diffusion of ions, e.g. ion pumps, getter ion pumps
    • H01J41/18—Discharge tubes for evacuating by diffusion of ions, e.g. ion pumps, getter ion pumps with ionisation by means of cold cathodes
    • H01J41/20—Discharge tubes for evacuating by diffusion of ions, e.g. ion pumps, getter ion pumps with ionisation by means of cold cathodes using gettering substances

Definitions

  • the present invention relates to an ionic pump of the getter type with a self-actuated discharge in a magnetic field and having the advantages of negligible outer magnetic field, reduced size and very light weight.
  • the ionization chamber of such a pump contains a positive electrode in the shape of a hollow cylinder and two negative electrodes made of a material, such as titanium or carbon which absorbs gaseous ions. These two electrodes are oppositely arranged at the open ends of the positive electrode.
  • This system is located in a magnetic field parallel to the axis of the cylinder and produced by a magnet arranged outside the enclosed space containing the system.
  • the present invention has for an object to provide an ionic pump of the getter type with a magnetic field which, whilst having a small volume and -a light weight, has hardly any outer magnetic lield.
  • the principle of the invention consists in reducing the outer eld by means of a compensating magnetic structure.
  • the present invention provides an ionic pump of the getter type using an ionization chamber, in which there prevails a magnetic field, having the following arrangements:
  • the ionization chamber is essentially constituted by a hollow cylinder of a non-ferromagnetic material connected on either side to ferromagnetic plates. It is surrounded by a magnet in the shape of a hollow cylinder magnetized in the direction of its axis and magnetically connected to the two ferromagnetic plates. Outside the chamber and coaxial with it, is arranged a second magnet, a so-called compensation magnet, preferably of identical shape to the first, magnetized in the opposite direction to that of the first and magnetically connected by one of its polar faces to one of the two plates of the chamber and by the other to a third ferromagnetic plate.
  • the assembly is surrounded by a magnetic screen in the form of ⁇ a box, two opposite walls of which are magnetically connected respectively to the two end plates of the assembly, each of the plates being capable of constituting one of the walls of the box.
  • magnetically connected indicates, according to common usage, any arrangement for which the reluctance between these elements is very small in relation to the total reluctance of lthe circuit.
  • the magnetically connected elements can therefore be either in immediate contact, or integral with one another, but may also be separated by a fairly narrow gap or connected by means of a third ferromagnetic element.
  • FIGURE 1 illustrates a non-compensated structure
  • FIGURE 2 illustrates the principle according to this invention
  • FIGURE 3 illustrates one construction of ionic pump according to this invention
  • FIGURE 4 illustrates an embodiment comprising two ionic pumps.
  • the pump which is the object of the invention even in its most simple form, i.e. without screening, has a very small leakage eld.
  • its magnetic structure is approximately symmetrical in relation to a plane.
  • the external fields produced by each half thus practically compensate for each other at a certain distance from the structure.
  • lthe screening which is used in the preferred embodiment can have reduced dimensions and its walls can be thin.
  • FIGURES 1 and 2 show that show the induction spectrum for a non-compensated structure and FIGURE 2 shows that found in a structure according to the invention. It may be seen that in the first case the magnetV 1 produces a ux the parasitic component of which, corresponding to the induction lines 2, is comparable to the useful component 3. This latter stems from the large extent of the polar faces, one of which is constituted by one whole side of the plate 4 and the other by the inner surface of the screening box 5 connected to the plate 6.
  • FIG- URE 2 This is no longer the case in the structure according to the invention and diagrammatically shown in FIG- URE 2.
  • a second magnet 7 magnetized in the opposite direction to that of 1 is connected on the one hand to the outer surface of the plate 4 andon the other hand to an inner surface of the screening box 5.
  • the parasitic flux is very reduced because the para- -sitic induction lines can only originate in the half situated towards the magnet 1 of the circumferential zone of the plate 4. In fact no induction line produced by the magnet 1 can pass through the plane of symmetry 9 of the structure.
  • the lessening in the parasitic flux results in an advantageous reinforcement of the useful induction, allowing the volume of the pump to be reduced and thus facilitating its use on fragile electronic tubes.
  • each of the two ferromagnetic plates supports an electrode made of a material which absorbs the ions of the gas to be pumped whilst a third electrode of annular shape taken to a positive potential in relation to the two previous ones is arranged in the space between the latter coaxially in relation to the line connecting them.
  • the invention is not limited to these types of pumps and it may be applied to any system of ionic absorption pumpsythe ionization chamber offwhich is subjected to a magnetic field.
  • the pump in FIGURE 3 is made-up of a discharge structure contained in an ionization chamber-10 vand of an outer structure 11 co-operating with the members of the chamber 16 in order to create a magnetic field limited to the chamber' 10.
  • This chamber- is constituted by a glass cylinder 12 sealed to two-plates 13,v 14 of ferromagnetic material, for example rKovar.
  • the plateV 13 which has a greater diameter than 14, comprises a gas inlet port 15.
  • a glass pipe 16 ⁇ sealed tothe plate 13 connects the pump to the electronic tube to be pumped.
  • These plates 13 and 14 have projections 17, 18' extend-
  • the projections 17, 18 are covered with sheets 19, 20 of a material such as carbon or titanium which can absorb the gases in fthe ionized state.
  • the wall 28 of the box 26 forms the ferromagnetic plate connected, according -to-the invention, to the lend of the compensation magnet 25.
  • the induction fiuxoband the two adjacent ferromagnetic plates at-:itsends can enclose the ionization chamber f a second pump cooperating with'the first.
  • the compensation magnet can be constituted by a solid cylinder arranged on the axis offthe pump.
  • the discharge electrode orelectrodes of the pump can be directlyv fed ⁇ bythe current conductors ⁇ of the velectronic tube to be pumped, the connecting conductor being inside the vacuum enclosure.
  • FIGURE 4- f shows an embodiment comprising two ionic pumps 4and vhaving two ionizationrchambere'as ⁇ described in paragraph (a) above.
  • a second hollow cylinder 32 constituting ⁇ the positive electrode of the second ionization chamber.
  • An electrical conductor 33 connecting the electrode 32 to the electrode 21 through an aperture 34 in the ferromagnetic plate 14.
  • Sheets 35 and 37 of a material absorbing gases in the ionized state just like the sheets 19 and 20. These sheets 36 randy 37 cover the ferromagnetic cylindrical elements and constitute the negative electrodes of the second ionization chamber.
  • An ionic pump of the getter type having an ionization space which is subjected to a magnetic field, comprising a hollow cylinder of non-ferromagnetic material defining the ionization space, a first ferromagnetic member arranged at one end of the hollow cylinder, a second .ferromagnetic member arranged at the other end of said hollow cylinder, at least one of .said ferromagnetic members supporting an electrode of ion absorbing ⁇ material on its surfacefacing the interior of the hollow cylinder, an annular Velectrode within the hollow cylinder arranged between the rfirst and the second ferromagnetic members and having'its open ends directed towards these members and adapted to be carried to a positive potential with respect to these members, an aperture in one of said ferromagnetic members forming an inlet for the gas to be pumped, a supply conductor to said annular electrode extendingthrough said aperture, a first magnet in the form of a hollow cylinder magnetized in the axial direction which surrounds vs
  • a pump as claimed in claim 1, comprising a surrounding magnetic screening structure in the form of a box magnetically connected to the first and third ferromagnetic members.
  • a second ionic pump .structure co-operating with the first ionic pump and arranged between the second .and third ferromagnetic members, said second pump structure also comprising a hollow cylinder of non-ferromagnetic material defining the ionization space and extending between said second and third ferromagnetic members, an electrode of ion absorbing material supported by at least one of said second and third ferromagnetic members and facing the interior ofthe.
  • an annular electrode within the hollow cylinder having its ends directed towards said second and third ferromagnetic members, ,an ⁇ aperture in said second ferromagnetic member forming an inlet for the gas to be pumped and providing communica- ⁇ tion between the ionizationspaces of the two pumps, a
  • a pump as claimed in claim l in which the second magnet is constituted by a hollow cylinder.
  • an ionic pump comprising a member of nonferromagnetic material defining an ionisation chamber containing members of ion absorbing material and surrounded by a magnet structure producing a magnetic field directed axially of the chamber, the improvement which comprises arranging compensating magnet means which are magnetized in the opposite direction to the magnet structure externally of said chamber in order to reduce the magnetic lield produced outside said chamber.
  • an ionic pump comprising a member of nonierromagnetic material defining an ionisation chamber containing two spaced members of ion absorbing material and an annular electrode arranged between said two members which is adapted to be carried to a positive potential and wherein a magnet structure is arranged around said chamber to produce a magnetic lield extending axially of said chamber and said annular electrode, the improvement which comprises arranging compensating magnet means which are magnetised in the opposite direction to said magnet structure externally of said chamber in order to substantially reduce the magnetic field produced outside said chamber.

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  • Electron Tubes For Measurement (AREA)
US122007A 1960-07-08 1961-07-05 Ionic pump Expired - Lifetime US3172597A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR832470A FR1269798A (fr) 1960-07-08 1960-07-08 Pompe ionique à champ magnétique extérieur négligeable

Publications (1)

Publication Number Publication Date
US3172597A true US3172597A (en) 1965-03-09

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US122007A Expired - Lifetime US3172597A (en) 1960-07-08 1961-07-05 Ionic pump

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US (1) US3172597A (enrdf_load_stackoverflow)
CH (1) CH372127A (enrdf_load_stackoverflow)
DE (1) DE1168010B (enrdf_load_stackoverflow)
FR (1) FR1269798A (enrdf_load_stackoverflow)
GB (1) GB938022A (enrdf_load_stackoverflow)
NL (2) NL137796C (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3582710A (en) * 1969-05-22 1971-06-01 Gen Electric Ultrahigh vacuum magnetron ionization gauge with ferromagnetic electrodes
US4167370A (en) * 1976-11-01 1979-09-11 Massachusetts Institute Of Technology Method of an apparatus for self-sustaining high vacuum in a high voltage environment
US5655886A (en) * 1995-06-06 1997-08-12 Color Planar Displays, Inc. Vacuum maintenance device for high vacuum chambers
US5939822A (en) * 1994-12-05 1999-08-17 Semix, Inc. Support structure for flat panel displays

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20180306175A1 (en) * 2017-04-25 2018-10-25 Edwards Vacuum Llc Magnetic focusing in an ion pump using internal ferrous materials

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2146025A (en) * 1935-12-28 1939-02-07 Philips Nv Coating by cathode disintegration
US2755014A (en) * 1953-04-24 1956-07-17 Gen Electric Ionic vacuum pump device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2146025A (en) * 1935-12-28 1939-02-07 Philips Nv Coating by cathode disintegration
US2755014A (en) * 1953-04-24 1956-07-17 Gen Electric Ionic vacuum pump device

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3582710A (en) * 1969-05-22 1971-06-01 Gen Electric Ultrahigh vacuum magnetron ionization gauge with ferromagnetic electrodes
US4167370A (en) * 1976-11-01 1979-09-11 Massachusetts Institute Of Technology Method of an apparatus for self-sustaining high vacuum in a high voltage environment
US5939822A (en) * 1994-12-05 1999-08-17 Semix, Inc. Support structure for flat panel displays
US5655886A (en) * 1995-06-06 1997-08-12 Color Planar Displays, Inc. Vacuum maintenance device for high vacuum chambers

Also Published As

Publication number Publication date
GB938022A (en) 1963-09-25
CH372127A (fr) 1963-09-30
DE1168010B (de) 1964-04-16
FR1269798A (fr) 1961-08-18
NL266745A (enrdf_load_stackoverflow)
NL137796C (enrdf_load_stackoverflow)

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