US2111757A - Vacuum discharge vessel - Google Patents

Vacuum discharge vessel Download PDF

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Publication number
US2111757A
US2111757A US739678A US73967834A US2111757A US 2111757 A US2111757 A US 2111757A US 739678 A US739678 A US 739678A US 73967834 A US73967834 A US 73967834A US 2111757 A US2111757 A US 2111757A
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United States
Prior art keywords
anode
current
cathode
discharge
diaphragm
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Expired - Lifetime
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US739678A
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English (en)
Inventor
Dallenbach Walter
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.)
MEAF Machinerieen en Apparaten Fabrieken NV
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MEAF Machinerieen en Apparaten Fabrieken NV
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/02—Details
    • H01J17/04—Electrodes; Screens
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/02—Cathode ray tubes; Electron beam tubes having one or more output electrodes which may be impacted selectively by the ray or beam, and onto, from, or over which the ray or beam may be deflected or de-focused
    • H01J31/04—Cathode ray tubes; Electron beam tubes having one or more output electrodes which may be impacted selectively by the ray or beam, and onto, from, or over which the ray or beam may be deflected or de-focused with only one or two output electrodes with only two electrically independant groups or electrodes

Definitions

  • a partition dividing the inner space of the discharge vessel into a smaller space adjoining the anode surface and a larger one.
  • the partition possesses one or several small apertures equal in size to the mean free length of path of the particles of the gas or vapor content, and means are further provided for operating the tube at a current intensity which, owing to the constriction of the discharge by the diaphragm in the space adjoining the active anode surface, involves a decrease in the number of positive ions, so that a drop in voltage increasing with the current intensity will take place in that space.
  • a further object is to limit the distance from the partition to the anode to a maximum equal to a few lengths of path of electrons in the gas or vapor.
  • Another object is to construct the apertures in the form of elongated channels.
  • Another object is to produce the partition from metallic material and to connect it to the anode by means. of aresistance.
  • a further object is to employ control electrodes for influencing the current passing through the opening of the partition.
  • Still anotherv object is to connect in series with the discharge tube a resistance or choker dimensioned so that the tube will carry out slow automatic oscillations similar to those of a flash lamp.
  • FIG. 1 is a diagram of a characteristic of a discharge tube according to the invention
  • Fig. 2 shows the construction of such a tube by means of a mercury cathode and an auxiliary ignition electrode
  • Fig.3 shows a cathode ray tube with deflecting electrodes
  • Fig. 4 shows a tube provided with two anodes which alternately may receive the cathode ray by means of control electrodes
  • Fig. 5 shows a tube, in which the partition made of metallic material is connected to the anode by a resistance
  • Fig. 6 shows an anode with a partition, in which a number of apertures having the form of small channels are provided;
  • Fig. 7 shows a diagram of connections for ob-- taining slow fiashlike oscillations.
  • Fig. 1 shows the current-voltage diagram of such a gas discharge tube. A more accurate examination shows. that in following the voltage characteristic up to the point where it begins to ascend a branch will be reached which rises in vertical direction. This means that the current J reaches saturation, the saturating current intensity dependingupon the gas pressure within the tube.
  • a tube of this kind is shown.
  • A is the anode;
  • B the diaphragm surrounding the anode; and
  • K a cathode. of the mercury or hot type.
  • an exciter anode E is, as a rule, required to maintain the exciter arc towards the cathode K, though the exciter anode becomes superfluous if enough current is takenfrom the cathode.
  • the saturating current intensity for the cur, rent passing from the cathode to the anode is brought about as follows:
  • a so-called striction cathode is formed which all electrons coming from the cathode have to pass.
  • a fixed relation exists between the electron current passing from the cathode to the anode and the positive stream of ions passing in reversed direction from the anode to the cathode.
  • the ratio of the electron current to the ionic current must be Jr m m being the mass of positive ions and me the mass of electrons.
  • the value for mercury vapor will therefore be 605, i. e., the electron current passing from the cathode to the anode is 605 times greater than the oppositely directed ionic current.
  • the positive ions projected by the positive ionic current Jp through the diaphragm opening from the chamber into the discharge space C must necessarily be supplied later on in some way, which is effected by the diffusion of neutral mercury atoms from the discharge tube through the diaphragm opening into the inside of the chamber. This diifusion is due to the temperature motion of the mercury atoms.
  • the number of neutral gas particles which diffuse at low gas pressure through a diaphragm opening is known to be dependent solely on the number of particles per unit of Volume and the temperature, i. e., the intensity of motion of these particles.
  • the electron current passing through the stric tion cathode formed in the diaphragm opening runs through the space towards the anode as a regular ray.
  • the striction cathode acts there fore in the hollow space E as a novel type of cathode (plasma cathode), as it is fed by the irregularly moving electrons, the so-called plasma, in the space C.
  • plasma cathode a novel type of cathode
  • current densities can be attained by means of this plasma cathode, which considerably exceed the densities of the usual hot cathodes. It thus becomes possible to produce with this plasma cathode in the chamber B a cathode ray of much higher density than could be attained with, say, a hot cathode.
  • this novel cathode may be used as cathode ray oscillograph by employing a fluorescent screen or a window of metal foil with a fluorescent screen arranged behind it instead of the anode A.
  • a fluorescent screen or a window of metal foil with a fluorescent screen arranged behind it instead of the anode A.
  • O is the window; D represents the deflecting electrodes and L the fluorescent screen.
  • the electronic ray electrodes D may be provided inside the chamber B to produce a transverse field, as indicated in Fig. 4.
  • the anode is preferably divided into the two parts A1 and A2 (Fig. i) which, according to the voltage applied, take up at the auxiliary electrodes D the electron current in whole or in part, or not at all.
  • Fig. 4 also shows how such a discharge vessel may be used as counter-contact amplifier in the manner usual in electron tubes. If the auxiliary electrodes D are supplied with control voltages by the line S, they can be taken oii amplified at the outlet A.
  • the discharge vessel will function as counter-contact generator whose oscillation frequency may be varied within wide limits.
  • the discharge vessel described may further be used for limiting current.
  • the current intensity cannot increase beyond the value at point P as long as the gas pressure maintains a certain value, and the tube can thus be employed as steadying resistance in front of apparatus which, for example, are always to be operated at a certain current intensity regardless of the feeding voltage.
  • hot cathode tubes are known, but in contrast with the latter considerable current intensities can be kept constant in this manner, according to the invention, by simple means and at low power input.
  • cathode K for the discharge and the formation of the plasma cathode proper in the opening F of the diaphragm B a hot or a mercury cathode with or without the exciter anode E may be employed in the usual way. If a mercury cathode is chosen, it is desirable to keep the mercury vapor pressure constant near the diaphragm opening, which can be done for instance by disposing the tube in a thermostat.
  • Another possibility consists in filling the tube with a rare gas of such high pressure that, in comparison, the mercury vapor pressure is of no importance.
  • the invention is thus of special importance for all electric discharge vessels serving as receivers, particularly independent receivers, of electric energy.
  • the back diffusion of neutral gas or vapor particles may further be impeded by causing the discharge-from the diaphragm or the like to the anode surface to take place in a channel whose diameter is comparable with that of the diaphragm and which terminates near the anode surface.
  • the back difiusing particles are compelled by this arrangement to move for several lengths of path inside a channel whose diameter is also comparable with the length of path. From the laws of the kinetic gas theory it is known that such a channel will increasinglyinterfere with the free motion of the particles in proportion to its length.
  • the diaphragm opening lengthened by the channel extending to the anode surface has, moreover, a particularly good effect according to the invention, as the soft electronic radiation from. the diaphragm opening in the directionof the anode finds only a relatively narrow space for. collisions with neutral gas particles for forming new pairs of ions.
  • the bottom of the body B maybe formed by a porous member G in which channels are provided.
  • a porous member G in which channels are provided.
  • the resistance It may therefore be relatively high, so that after the anode A has taken over the current conduction, only a relatively small current or induction current flows through the diaphragm carrier B, the conductor H and the resistance R.
  • the resistance B may of course be entirely disposed inside the discharge vessel to dispense with the conductor H. This is shown in Fig.
  • the diaphragm body B provided with a plurality of openings F is positioned directly on the anode A by means of an interposed member L of poorly conducting material, and the openings F are elongated by the channels M and extend up toward the active anode surface to prevent back difiusion of neutral gas or vapor particles.
  • the intermediate member L serves also for supporting the metallic diaphragm body B. It is possible to construct the body B entirely from poorly conducting material and to position it on the anode or its current-carrying conductor.
  • a drop in voltage will take place, at least near the peak value of the current in the space adjoining the active anode surface. After the drop in voltage required for initiating greater current intensities has been exceeded, the current intensity will instantly increase to an amount correspondingto the positive branch of the current-voltage characteristic and, if this branch rises relatively steeply, only an immaterial increase of the operating current intensity will take place, so that the line diagram of the current intensity will have approximately rectangular shape.
  • the main feature of the invention is to successfully influence the drop in voltage of the tube by relatively simplein-built means near the. anode in such a way that it will increase in wholeor at least in part with the current intensity so as to avoid series impedances which complicate and increase the cost of the plant and involve additional losses or a poor power factor.
  • the electric discharge vessel serves for producing light
  • the diaphragm arranged near the anode surface may simultaneously be used for producing the brightness of the discharge or an approximately point- 7713 and m represent the mass of the electron and positive ion.
  • Ne refers to the number of positive charges which pass through the screen opening of the cross section F
  • J refers to the strength of the discharging current.
  • each current intensity and difference in pressure desired will correspond to a certain size of the cross-sectional opening, the exact ascertainment of which is leftto experiments.
  • the saturation current intensity amounted to about 1 amp. at a temperature of the mercury cathode of about 17 C., a mercury vapor pressure of about 10- mm. mercury column and a diaphragm diameter of 5 mm.
  • a gas discharge vessel according to the invention is operated with current intensities near the point P (Fig. 1) where the characteristic changes from an approximately horizontal to an approximately vertical course and if a series resistance to be found by testing or a correspondingly dimensioned series choke DR (Fig. 7) are inserted in the circuit, the tube will carry out slow oscillations, which is probably due to the following causes:
  • a certain current intensity prevails at first under the influence of which gradual evacuation of the chamber B is effected.
  • this discharge will break, as inside the chamber the current and the voltage will rise, owing to the decrease in the number of ions.
  • the chamber will fill up with gas from the space E and the current intensity can rise again. This process is repeated periodically.
  • the frequency of the oscillations ranges from many seconds to fractions of a second and can be regulated within these limits by the size of the chamber, the opening thereof, the gas pressure or the value of the saturation current intensity depending on the gas pressure. In this way it becomes possible to operate lamps working without outer elements, such as condensers, devices for an auxiliary discharge current, etc., at a predetermined interrupting frequency. Lamps of this kind may suitably be used for advertising purposes, signal plants, etc.
  • An electric discharge vessel containing an ionizable medium under sufficiently high pressure to support a current discharge comprising at least one anode, a cathode, a partition between the anode and the cathode dividing the discharge vessel into a smaller space directly adjoining the active anode surface and a larger space, said partition having an opening therein for passage of said discharge, the diameter of said opening being of the magnitude of the mean free path of the particles of the ionizable medium, whereby the discharge is constricted at this point to a fraction of its cross section in the remainder of the space and the current density is increased, the latter causing a paucity of ions and a potential drop corresponding to a current increase, and an auxiliary electrode adjacent the path of discharge provided with a suitable potential for controlling said discharge.
  • An electric discharge vessel containing an ionizable medium under sufliciently high pressure to support a current discharge comprising at least one anode, a cathode, a partition between the anode and the cathode dividing the discharge vessel into a smaller space directly adjoining the active anode surface and a larger space, said partition having an opening therein for passage of said discharge, the diameter of said opening being of the magnitude of the mean free path of the particles of the ionizable medium, whereby the discharge is constricted at this point to a fraction of its cross section, in the remainder of the space and the current density is increased, the latter causing a paucity of ions and a potential drop corresponding to a current increase, and two electrodes between said anode and said partition on opposite sides of the path of discharge for controlling its direction.
  • An electric discharge vessel containing an ionizable medium under suiiiciently high pressure to support a current discharge comprising at least one anode, a cathode, a partition between the anode and the cathode dividing the discharge vessel into a smaller space directly adjoining the active anode surface and a larger space, said partition having a plurality of openings therein for passage of the discharge, the diameter of said openings being of the magnitude of the mean free path of the particles of the ionizable medium, whereby the discharge is constricted at this point to a fraction of its cross section in the remainder of the space and the current density is increased, the latter causing a paucity of ions and a potential drop corresponding to a current increase, and an auxiliary electrode-system provided with a suitable potential adjacent the path of discharge for controlling said discharge.
  • An electric discharge vessel containing an ionizable medium comprising an anode, a cathode, a partition of conducting material between the anode and a cathode dividing the vessel into a smaller space directly adjoining the active surface and a larger space, said partition being connected with the anode by a resistance outside the vessel, said partition having an opening therein, the diameter of the opening being of the magnitude of the mean free path of the particles of the ionizable content, said structure causing a paucity of ions and a potential drop corresponding to a current increase, and an auxiliary electrode-system provided with a suitable potential adjacent the path of discharge for controlling said discharge.

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  • Physical Or Chemical Processes And Apparatus (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Gas-Filled Discharge Tubes (AREA)
  • Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
US739678A 1934-06-22 1934-08-13 Vacuum discharge vessel Expired - Lifetime US2111757A (en)

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Application Number Priority Date Filing Date Title
DE2111757X 1934-06-22

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US (1) US2111757A (fr)
FR (1) FR775293A (fr)
GB (2) GB440566A (fr)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB8602292D0 (en) * 1986-01-30 1986-03-05 English Electric Valve Co Ltd Thyratrons

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Publication number Publication date
GB440636A (en) 1935-12-30
GB440566A (en) 1935-12-30
FR775293A (fr) 1934-12-21

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