A plasma source of negative atomic ions
(57) Abstract:Usage: ion technique. The device allows you to get directly at the exit of the plasma source does not contain electrons pulsed beams of negative atomic ions in electronegative gases. The essence of the invention: a source of negative atomic ions comprises a sealed discharge chamber with an inlet and outlet connected to the power supply electrodes: basic, placed in the chamber, and accelerating beyond its outlet. The inner wall of the chamber length L in the discharge zone is made conductive and connected to a power source, the power supply main and the accelerating electrode and the conductive surface of the selected pulse output hole is placed in the conductive wall, and the length L of the conductive surface is found from the condition L 2D L < 1, where D is the width of the electric discharge chamber, I is the length of the zone of discharge. 2 Il. The invention relates to the field of electrical engineering, in particular to electronic discharge devices, and can be used to create devices that simulates the Earth's ionosphere, in the research of the characteristics of elementary tap the x beams.At the present time is a very urgent task of creating technology plasma sources monoenergetic beams of negative ions of low energy (a few eV). Physical modelling of the effects of flows of atomic oxygen on the outer onboard equipment spacecraft operating in low earth orbits, it is especially important to obtain ion beams without accompanying electrons, complicating the modeling field conditions due to ionization and excitation.The authors are not known plasma sources beams of atomic ions that do not contain electronic components.Known plasma sources of negative ions. For example, a plasma source of negative ions of oxygen (Danilin T. I. and other operating rules, 1968, No. 3, S. 158), based on the use of the penning discharge with cold cathodes and ejecting the ions perpendicular to the magnetic field. It contains housed in a sealed enclosure two cathode pole piece of the permanent magnets, flat ferromagnetic circular anode with a hole in the center for the extraction of ions, and accelerating electrode and an electrostatic lens. When the discharge current of 150 mA, the anode voltage of 500 V and yuushin electronic current of 30 mA.Disadvantages source are the electronic components of the output beam current which is 600 times the beam current OF-and also the comparative complexity of the design.Closest to the proposed invention achieved the effect is chosen as a prototype plasma source for atomic hydrogen ions (H-) [Antipov, S. P. Elizarov L. I. Martynov M. I. Chesnokov C. M. PTE, 1984, N 4, S. 42-44] with axially symmetric geometry and radial magnetic field. The main elements of its design are: a sealed enclosure with an opening for entry of the working gas inside the enclosure to be heated hollow cathode, an auxiliary electrode (used for ignition of the discharge), the main anode in the form of a disk, provided with the outlets, which is located near the accelerating electrode, a magnetic system that creates a radial magnetic field and consisting of inner and outer magnetic poles, representing axially spaced hollow steel cylinders with magnetic coil between them (the cathode is located in the inner pole). The discharge burns between the hollow cathode and the main anode. Ions are extracted in the direction perpendicular magnetic p of the ion current to 0.7 And at a current associated electrons 1,2.1,4 A.The main disadvantage of this source is also a relatively large share of electronic components in the beam extracted particles. Another significant disadvantage is the complexity of the design, due to the need of the use of the magnetic coil, the heated cathode and auxiliary anode.The technical effect of the plasma source of negative atomic ions of our proposed design is to provide directly at the exit of the plasma source of stable intense pulsed beams of negative ions in electronegative gases, containing no accompanying electrons. Proposed source is structurally simple and compact, allowing you to use it in laboratory facilities are limited in size, simulating the conditions of the earth's ionosphere.The technical effect is achieved in that the plasma source of negative atomic ions is a sealed discharge chamber with an inlet and outlet connected to the power supply electrodes: basic, placed in the chamber, and accelerating placed at its outlet. New it is, " used the term "zone of discharge" i.e. the area where the ionization of the gas as possible constructive implementation of the present invention, when the conductive wall is the inner surface of one of the main electrodes) are made conductive and connected to a power source, the power source is selected pulse, the output hole is placed in the conductive wall, and the length L of the conductive surface is found from the condition L 2S, L < l, where D is the width of the electric discharge chamber, l is the length of the zone of discharge.Studies of electrokinetic characteristics of gas discharge plasma by us theoretically substantiated and experimentally confirmed the ability to control the diffusion of charged particles in decaying plasma at scales much greater than the Debye radius rdby changing the potential of the conducting boundaries of the plasma. It is possible to obtain in the decaying plasma pulse-periodic discharge in electronegative gases regulated by the duration of the threads on the wall of negative atomic ions, containing no electrons. Theoretical substantiation and experimental data is given in the Appendix.In Fig. 1 shows a diagram of the proposed plasma source, hectrol 6, switching power supplies 7, 8 and 9, a conductive surface (wall surface electrode) 10, the system of the gas inlet 11, the vacuum chamber 12, the length of the conducting surface L, the length of the discharge zone l, the width of the electric discharge chamber D.In Fig. 2 depicts the dependence of the electron concentration Neand the diffusion flux of negative ions in the conductive wall G-in pulse-periodic discharge in dependence on time t, where T is the repetition period of the discharge pulses, T0and T1accordingly, the moments of the formation of ion-ion plasma in the absence and in the presence (dashed line) of the control voltage applied to the conductive wall at time Te.The proposed device operates as follows. The hermetic housing 1, is connected from the outlet 3 to the vacuum chamber 12, a pre-pumped. After using the system I working gas 11 provide the gas flow through the inlet 2; leveling speed is chosen such that the working pressure in the source does not exceed 0,1.of 0.2 Torr (Gabovich, M. D. Physics and technology of plasma ion sources. M Atomizdat, 1972, S. 177). Using the pulse source 7 in the working gas excite yodat of volume, the plasma becomes ion-ion (see Appendix). When applying for accelerating electrode 6 from the power source 9 of the positive voltage U at the time t < T T0at the exit of the plasma source 3 receives the pulsed beam of negative ions with energy U.The transition to the regime of ion-ion plasma in an earlier time T1< T0can be achieved if you apply using a power source 8 at parietal electrode small positive potentials Uesince the time Te< T1< T0. In this case, T1depends on Teand Ue. By varying the last two parameters can be adjusted T1and thereby to provide a pulsed beam of negative ions that do not contain electrons, with the repetition period of pulses T and duration T-T1> T-T0. Thus, due to the fact that part of the wall of the discharge chamber is made conductive in the discharge zone, there is an additional parietal electrode, the control voltage which allow you to adjust the pulse width of the beam of negative ions.Declared plasma source is implemented in the following design 35 mm, with aluminum electrodes and parietal Nickel cylinder length 70 mm tube was pumped oxygen and lit periodic-pulsed discharge with T 320 μs, the voltage between the discharge electrodes 900, the current pulse 50 mA. Stationary pressure in the tube when this was 0.04 Torr. The current of charged particles through the outlet diameter of 1.2 mm was measured using a flat molybdenum collector, the ratio of the electronic and ionic components in the beam was monitored with a probe measurements near the outlet (Kozlov, O. C. electric probe in the plasma. M Atomizdat, 1969). The temporal resolution in the measurements was 10 μs. The results of measurements of ion Iiand e Iecurrents at the collector when U + 8 in moments of t1100 μm, t2180 μs after the discharge presented in the table. As can be seen from the table, the current of the ion beam components by more than an order exceeds the electron current.A plasma ion source was used for laboratory simulation of space flight spacecraft in the ionosphere of the Earth. During operation within 120 hours basic source parameters (pulse current at a specified voltage discharge, the working pressure is ucke electronic component is virtually absent (see table), played.Thus, the plasma source of negative atomic ions provides the possibility of obtaining stable intense ion beams, so you can use it when creating a device that simulates the Earth's ionosphere, in the research of the characteristics of elementary processes in collisions of negative ions with neutral and charged particles, and in the generation of atomic beams. In addition, such devices may be used as sources of negative ions in electronegative gases with a sufficiently large (>0.5 eV) energy of the electron affinity (H, CL, I, and others) in electrostatic accelerators in industrial process plants for various purposes.The application.It is known that when placed in the plasma charged body near its surface polarization of the plasma, leading to shielding of the corresponding electric field. The characteristic spatial scale of such shielding is equal to the Debye radius
rd[cm] 500 (Te[eV]/N[cm-3])1/2< / BR>(where Teand N are the temperature and concentration of charged particles). For typical conditions Gal t) electric potentials, non-occurrence of the independent (or dependent) electric discharge directly does not change the distribution of electric fields in plasma, and therefore, changing the nature of diffusion of charged particles. However, after a time of order
t[c] = 1/p= 1,7910-5/N[cm-3]1/2< / BR>(the time scale charge separation in the plasma after enabling this potential will change the magnitude of the parietal spike potential on the boundary of the plasma. Depending on the magnitude of the steady-state potential Eph at this boundary will change the nature of the recombination of charged particles: particles having the normal component of the kinetic energy En> Eph will recombine at the border, with energy En< Eph reflected by a potential barrier. If the characteristic size of the conductor at the boundary of the plasma L> (diffusion length), in accordance with the changed boundary conditions changes the profile of ambipolar potential in the plasma, controlling the speed of diffusion of charged particles to its borders.The nature of the diffusive motion of charged particles was studied experimentally in the decaying plasma pulse-periodicacademic in a glass tube with a diameter of 35 mm with molybdenum electrodes. Inside the tube was placed made of Nickel foil hollow metal cylinder with a length of 70 mm, adjacent to the walls of the tube. Were made probe to measure the distribution of electric potential and electron concentrations in the decaying plasma inside the Nickel cylinder in conditions when he was served a small positive and negative potentials. It is established that the application of these potentials entails changing the rate of diffusion care of charged particles from the volume. So, in the decaying plasma of helium (helium pressure of 0.7 Torr, a pulse of current of 0.7 a, pulse duration 15 μs, T 440 ISS) through Te20 μs after the end of the discharge wall of the cylinder pulse was applied positive voltage with duration of 200 μs and an amplitude of the 5th Century In the probe measurements has been reported in more rapid decrease of the electron concentration on the axis of the discharge tube (1,110 land only11up to 6,01010cm-3instead 9,01010cm-3within these 200 µs. Thus, the ability to adjust the speed of diffusion processes in the evolution of the gas discharge decaying plasma of low pressure by small changes of the potential of the conductor Eazy electrons, as well as positive and negative ions in the decaying plasma of electronegative gases. The ionic composition of such a plasma is determined mainly molecular ions (A+2formed in the discharge due to ionization of electrons and atomic ions (A-appearing in the discharge in the processes of dissociative sticking. The analysis showed that the diffusive decay of the plasma of electronegative gases occurs in two stages. In the first stage is the ambipolar diffusion of electrons and positive ions, negative ions are locked in volume due to the presence of ambipolar electric field and wall jump potential. At the end of phase with decreasing electron density radial electric field ceases to hold the electrons, and they instantly go from volume to the walls. In the second stage, the plasma consists of positive and negative ions in the almost complete absence of electrons; the collapse of the plasma is determined by the joint diffusion of ions of different sign. In the decaying plasma electron temperature usually does not exceed 0.1 eV, so the processes of ionization and dissociative sticking with large energy is l, not play a prominent role in the balance of concentrations of A-then, as follows from the obtained theoretical relationships, the transition to the second phase occurs through time
after the discharge, where the diffusion length, Dpthe coefficient of diffusion of positive ions; and0the ratio of the concentration of negative ions to the concentration of electrons by the end of the discharge.Performed the experiments on the study of pulse-periodic discharge in oxygen plasma using different discharge devices. The measurement probe volt-ampere characteristics of the discharge in a glass tube with a diameter of 35 mm at a pressure of 0.07 Torr, T 560 µs, pulse duration 32 μs, the current pulse of 10 mA found that through T0200 μs after the discharge occurs an abrupt transition from electron-ion to ion-ion plasma, due to diffusion care of electrons from the volume while maintaining the most part positive and negative ions. A similar effect was observed at T020.50 μs after the discharge in a pulse-periodic discharge T 150.500 ISS, detailspayment density currents of negative ions from an ion-ion plasma in murine probe at a potential of + 5 V was 10 μa/mm2and more.In accordance with the foregoing, when combined effect of formation of the ion-ion plasma and methods of control diffusion of charged particles the evolution of the electron density Neand the diffusion flux of negative ions on the wall G-will fit shown in Fig. 2. Feeding on parietal electrode discharge device adjustable on the magnitude and duration of the potentials Ueat some time Te(the dotted line in Fig. 2), it is possible to provide on the boundary of the plasma stream of negative ions by the duration t of T1> T T0(where T1depends on Teand Ue). Note that this way you can get a pulse stream of negative ions to the wall even when the "natural" way, it will not be realized, i.e., T < T0. A plasma source of negative atomic ions, including hermetic discharge chamber with an inlet and outlet connected to the power supply electrodes: basic, placed in the chamber, and accelerating placed at its outlet, characterized in that the inner wall of the chamber length L in the discharge zone is made conductive and Soea wall, and the length L of the conductive surface is found from the condition L 2D L < l, where D is the width of the electric discharge chamber, l is the length of the zone of discharge.
FIELD: ion-plasma engineering.
SUBSTANCE: proposed closed electron-drift ion source that can be used for designing sources generating ribbon electron beams of inert and chemically active gases has hollow housing that functions as cathode with emission slit and working gas admission ducts made in its butt-end walls, magnetic tips, anode mounted within housing opposite mentioned slit, and magnetomotive force sources; magnetic tips characterized in reduced risk of erosion are provided with removable shielding plates mounted to keep within definite geometry proportions between plate size and emission slit aperture.
EFFECT: enhanced service life, easy disassembly, and reduced maintenance charges of ion source.
4 cl, 2 dwg
FIELD: device for producing ions used for treatment of part surfaces and coating them.
SUBSTANCE: ion beam source has hollow housing; anode designed for connection with positive pole of dc voltage supply and disposed within housing; cathode designed for connection with negative pole of dc voltage supply and provided with slit used for emitting ions and spaced apart from anode; source of magnetomotive force; and at least one channel for conveying working gas into mentioned hollow housing; novelty is that mentioned hollow housing is at least partially formed by trough closed in axial direction and provided with slit and anode disposed along this trough. The latter may be composed of several sections whose ends are butt-joined together and two or more curvilinear trough-forming sections. Such mechanical design makes it possible to build a number of ion beam sources of different size, shape, and ion beam direction from relatively small set of unified components and to treat parts of complex shape and curvilinear surfaces.
EFFECT: facilitated mass production of different-size ion sources; improved operating characteristics and enlarged functional capabilities of proposed ion sources.
16 cl, 7 dwg
FIELD: mass-spectrometry in high-sensitivity component analysis of solids, gases, and liquids.
SUBSTANCE: proposed method for reducing background level of glow-discharge ion source incorporating hollow cathode includes reduction of desorption intensity of pollutants from surfaces of discharge-chamber parts by reducing plasma density in discharge chamber while reducing pressure of plasma-forming gas. Novelty is that hollow cathode used for the purpose is made of getter material and sprayed within discharge chamber just before analyzing the specimen. High-melting materials having minimal number of isotopes, such as Ta, Nb, and Co, can be used as getter material.
EFFECT: enhanced productivity and sensitivity of analysis.
2 cl, 2 dwg
FIELD: charged particle optics; energy and mass analyses.
SUBSTANCE: charged particle beam 1 is passed through dispersing element 2 whereupon it is passed through correcting element 3 which is essentially set of electrodes producing electric field perpendicular to beam motion direction. Diaphragms 5, 6, and 7 are large enough to pass all particles of beam. When all particles are within correcting element near surface 4, electric potential across electrodes is varied so that this potential variation approximately equals ΔΦ(P) ≈ W(P)/q, where W/P is mean value of particle coherent energy at point P; q is particle charge. This condition being satisfied, total mean particle energy equal to sum of kinetic and potential energies but slightly depends on point P coordinate after potential change-over and, hence, spread in total energy of all beam particles becomes lower than original spread in kinetic energy.
EFFECT: reduced energy spread of charged particles in short-length beams at same particle number in beam.
1 cl, 2 dwg
SUBSTANCE: wide-angle gaseous ion source contains base volume discharge formers including array-arranged hollow cathode and anode, and at least one interconnected auxiliary discharge formers. Auxiliary discharge formers is plasma accelerator with closed electron drift of narrow acceleration zone, containing orificed azimuthally closed anode arranged in ring cavity formed by magnetic circuits, and orificed azimuthally closed ionisation channel of working medium and ion acceleration walls of which are formed by poles of magnetic circuits of geometrical forms providing formation of curved electric and magnetic fields. Besides source has second auxiliary discharge former in the form of second plasma accelerator containing second identical orificed azimuthally closed channel of ion output and coaxial to first one.
EFFECT: allows for ion beam of any diameters with uniform distribution of ion density along demanded length from ion source.
9 cl, 5 dwg
SUBSTANCE: method of obtaining metallic nanoclusters in free-state involves depositing a substance on a substrate in nano-dispersed phase and bombarding the obtained target with accelerated heavy ions in elastic deceleration of ions. Electron-microscopic analysis of the substance, ejected from standard nano-dispersion targets of gold with average islet-grain size in the 2-30 nm under bombardment by atomic ions with 38 keV energy in elastic deceleration mode, indicates desorption of nanoclusters with size ranging to 20 nm with output of about 0.1 nkl/ion in the 4-8 nm range.
EFFECT: use of cheap sources.
SUBSTANCE: invention relates to the technology of generating streams of negative ions and can be used in charged particle accelerators, plasma heating systems and other devices. The method of generating negative ions is based on desorption of hydrogen particles in form of negative ions from the surface of a converter, made from material with negative electron affinity, for example diamond. To increase intensity of the beam of pulled negative ions in immediate proximity of the converter, high-current gas discharge plasma is generated, which is a source of intense streams of neutral atoms and electrons, which provide for saturation of the atomic layer adsorbed on the surface of the converter and filling the conduction zone with electrons. Molecular hydrogen is fed to the converter such that, it flows through the dense gas discharge zone so as to increase degree of dissociation. Negative electrons are pulled from the converter, bypassing plasma columns. The converter used is an anode or part of an anode of a gas-discharge cell.
EFFECT: increased intensity of beam of negative ions of hydrogen isotopes without using alkali metals as catalyst.
2 cl, 1 dwg
SUBSTANCE: device comprises gas-dicharge chamber with anode and three groups of cathodes, source of three-phase grid voltage connected to unit of heating supply, made of device for control of heating voltage and step-down heating transformer, unit of discharge supply with three switching diodes, three groups of cathodes are connected as delta and joined to output windings of heating transformer, negative output of discharge supply unit is connected to middle points of output windings of heating transformer through three switching diodes, and positive one - with anode of gas-discharge chamber, unit of heating supply additionally comprises controlled rectifier and inverter, three outputs of which are connected to primary windinfs of three step-down heating transformers, and control inlets of controlled rectifier and inverter are connected to outlets of heating voltage control device, power inputs of controlled rectifier are connected to source of three-phase grid voltage. Method for device operation consists in the fact that in unit of heating supply three-phase grid voltage is transformed into DC voltage with voltage values that varies from minimum to maximum by means of controlled rectifier with device of heating voltage control, and current values of DC voltage are transformed in inverter with device of heating voltage control into three phase-shifted AC voltages by 120° in the form of meander, which are sent to primary windings of three step-down heating transformers.
EFFECT: reduced chances of high-voltage breakthroughs in ion-optical system of ion source, improved focusing of generated ion bundle with preservation of high resource of cathodes operation.
2 cl, 3 dwg
SUBSTANCE: double-beam ion source consists of a housing in which there are two independent ion beam sources which form two independent and non-crossing beams directed in different sides. The housing is divided by a common cathode into two coaxial insulated gas-discharge chambers, and each gas-discharge chamber has its own anode and system for supplying working gas, where the common cathode is electrically connected to the housing.
EFFECT: design of two independent and non-crossing beams, directed in different sides in a single ion source.
2 cl, 1 dwg
SUBSTANCE: invention can be used in electron and ion sources which generate large cross-section beams. The charged particle plasma emitter has a discharge chamber with an axial hole and a gas inflow channel, a shaper in form of a hollow cylinder, an emission electrode, a ring placed inside the shaper, and voltage source for maintaining potential of the ring independent of the potential of the shaper. The ring is in form of several electrically insulated electrodes formed by dissecting a hollow flattened cone, whose smaller end faces the hole of the discharge chamber, and places symmetrically about the axis of the emitter with possibility of changing the angle of inclination and controlling electric potential of the said electrodes.
EFFECT: high energy efficiency of the plasma emitter when generating beams of charged particles with different form of the cross section using the same emitter and high efficiency of the installation owing to possibility of generating beams not only with current density distribution which is symmetrical about the axis, but with asymmetrical distribution of current density as well without changing the structure of the emitter.
4 cl, 4 dwg
FIELD: cathode-luminescent analysis of materials, plasmochemistry, quantum electronics, and the like.
SUBSTANCE: proposed method designed for shaping high-energy (hundreds of keV) subnanosecond (t ≤ 1 ns) charged particle beams whose current density amounts to tens of amperes per cm2 in gas-filled gap at atmospheric and higher pressure involves following procedures. Volumetric pulsed discharge is effected in gas-filled electrode gap and electron beam is shaped during breakdown of discharge gap as soon as parameter U/(p x d) is brought to value sufficient for shaping runaway electron beam between front of plasma propagating from cathode and anode and volumetric discharge plasma moving to anode is shaped by pre-ionization of gap with fast electrons formed across voltage pulse wavefront due to intensifying field on anode and/or on cathode plasma spots, where U is voltage, V; p is gas pressure, torr; d is gas-filled gap, mm.
EFFECT: enhanced energy and current density of generated subnanosecond electron beams.
FIELD: electronic engineering.
SUBSTANCE: proposed method and device make use of triangular-wave generator that produces triangular-waveform current signal conveyed to scanning coil for electron beam displacement in first scanning direction Y and rectangular-wave generator that produces rectangular-waveform current pulse arriving at deflection coil for displacing electron beam in second scanning direction X perpendicular to first scanning direction Y. Triangular-waveform current signal produced by triangular-wave generator is modulated to eliminate hysteresis effect in scanning coil. In addition, leading edge of rectangular-waveform current signal is timed at definite offset relative to peaks of triangular-waveform current signal so as to distribute return points on electron beam route in second scanning direction.
EFFECT: affording uniform scanning and eliminating hysteresis problems and heat concentration on diaphragm.
10 cl, 18 dwg
FIELD: quantum electronics, spectrometry, and plasma chemistry.
SUBSTANCE: proposed method for firing sparkless discharge in solid gases includes ignition of main charge between first and second electrodes by applying high-voltage pulse minus across first electrode and its plus, across second one, gas being pre-ionized with aid of low-energy electron beam, photons, and plasma electrons produced directly within main-discharge space; low-energy electron beam is produced by means of open barrier discharge with high-voltage pulse applied between first electrode made in the form of grid disposed on insulator surface and additional electrode disposed on opposite side of insulator; main charge is fired not earlier than ignition of open barrier discharge; the latter and main discharge are ignited within one gas-filled chamber. Device implementing proposed method has first and second electrodes forming main discharge gap, and high-voltage pulsed power supply; first electrode is made in the form of grid disposed on insulator surface whose opposite side mounts additional electrode; high-voltage pulsed power supply is connected through minus terminal to first grid electrode and through plus one, to second electrode; it functions to ignite main discharge; additional high-voltage pulsed power supply for open barrier discharge is connected through plus terminal to first grid electrode and through minus one, to additional electrode; first grid electrode, second electrode, additional electrode, and insulator are mounted in same gas-filled chamber.
EFFECT: enhanced main-charge stability due to enhanced efficiency of gas pre-ionization in main discharge gap from pre-ionization source disposed within main discharge space.
4 cl, 5 dwg
FIELD: high-voltage electrovacuum engineering; arc-control vacuum chambers, including direct-current ones, for various switches used in power engineering, industry, and transport.
SUBSTANCE: vacuum current switch incorporating proposed vacuum chamber with magnetic field that serves as OFF-operation factor applied to high-voltage gap formed by axisymmetrical electrodes disposed in insulating shell, at least one of electrodes being made movable due to connection to shell through bellows affording high-voltage circuit closing and opening during its reciprocation, has electrode system built of two basic parts: (a) contact part proper with electrodes held in one of two states (open or closed) and (b) permanently open electrode part (arc-control chamber) separated from contact members and made in the form of two electrodes (such as coaxial ones) installed so that as they move away from part (a), discharge current path increases and currents in adjacent electrodes flow in opposite directions, and direction of magnetic field set up due to them affords arc movement from part (a) to arc-control chamber. Such design of arc-control chamber provides for disconnecting currents ranging between 300 and 10 000 A at voltages up to 10 kV.
EFFECT: facilitated manufacture, reduced size and mass of chamber.
3 cl, 1 dwg
FIELD: charged particle beam generation for quantum electronics, cathode-luminescent analyses, plasma chemistry, and other fields.
SUBSTANCE: proposed method for enhancing density of sub-nanosecond electron beam that can be used in studying interaction between charged particle flow and some material includes firing of volumetric high-voltage pulsed discharge in gas-filled gap between electrodes at reduced gas pressures P: Pmin ≤ P < 300 torr, where Pmin is minimal gas pressure at which beam current length is not over -0.25 ns and can be gradually varied within specified range between approximately 0.1 and 0.25 ns. Maximal current density and beam current value are approximately 2.2 kA/cm2 and 1 kA, respectively.
EFFECT: ability of varying gas pressure within specified limits.
1 cl, 1 dwg
SUBSTANCE: proposed method of obtaining an electron beam involves applying supply voltage between a cathode with a cavity and an anode. A high-voltage discharge is initiated in a gas-discharge cell. A plasma forms in the cavity of the cathode, which provides for emission of electrons, accelerated by the strong field of the high-voltage discharge. The formed plasma has low density, for which purpose the surface of the cathode cavity is made from a dielectric. The generated electron beam can also be used as an auxiliary electron beam, which is directed over the surface of the open part of the cathode with a cavity. At the open part of the cathode on the side of the anode, a high-current electron beam is then formed. The device for generating an electron beam comprises an anode and a hollow cathode with an opening on the walls, which is located near the anode, all put into a gas-discharge cell. The wall of the hollow cathode with an opening is made from a dielectric sheet with an opening. The high-voltage power supply is connected to the anode and cathode.
EFFECT: provision for operation of sources under high pressure.
3 cl, 7 dwg
SUBSTANCE: invention relates to electronics and can be used in physical electronics, quantum electronics, plasma chemistry and diagnostic measurements. The method of making an electron beam involves igniting high-voltage discharge in a gas-discharge cell by applying power supply voltage between a cathode and an anode. Additional flow of ions is provided in the space between the cathode and the anode, which provides additional ionisation of gas with an auxiliary electron beam whose electrons are accelerated in the strong field of the high-voltage discharge. The auxiliary electron beam is generated on the perimetre of the cathode surface on the inner wall of an annular electrode. The device for generating an electron beam has a cathode and an anode placed in a gas-discharge cell, and a high-voltage power supply which is connected to the cathode and the anode. On the inner surface of the cathode there is an annular electrode on the inner wall of which an auxiliary electron beam is generated. In order to reduce discharge current, the flat part of the annular electrode on the anode side is covered by a dielectric plate with an opening whose diametre coincides with the inner diametre of the annular electrode.
EFFECT: wider operating pressure range of gas, as well as provision for high discharge stability with respect to sparking.
5 cl, 7 dwg
SUBSTANCE: invention relates to a device and a method of changing properties of a three-dimensional formed component (2) using electrons, having an electron accelerator (3a; 3b) for generating accelerated electrons and two electron outlet windows (5a; 5b). Both electron outlet windows (5a; 5b) are opposite each other. Both electron outlet windows (5a; 5b) and a reflector (7a1; 7a2; 7b1; 7b2) bound the process chamber in which the surface or outer layer of the formed component (2) is bombarded with electrons. Energy density distribution in the process chamber is recorded from spatial measurement using a sensor system.
EFFECT: uniform modification of the entire surface or outer layer of a formed component, increased efficiency of the installation.
25 cl, 3 dwg
SUBSTANCE: discharge is ignited between a flat cathode and an anode, which is made in the form of a thin needle with a small radius of rounding. The proposed invention makes it possible to produce a stable microdischarge with a quite simple and inexpensive method, which does not require vacuum plants and does not require external injection of electrons, since the discharge burns in atmosphere and is independent. The invention may be used to create plasma-chemical reactors and gas analysers, and also in plasma sputtering and alloying of materials in sections of micron size.
EFFECT: increased stabilisation of a smouldering microdischarge under atmospheric pressure.