Method and device for producing sparkless discharge in solid gases (alternatives)

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

 

The invention relates to electronics and can be used in physical electronics, quantum electronics, spectroscopy, plasma diagnostic measurements.

Known methods for producing fire resistant discharges in dense gases, namely, that between the first electrode and the second electrode, which form the main bit period, carry out the pre-ionization gas, then ignite the main discharge between the first electrode and the second electrode, the pre-ionization of the gas is performed by photons, electrons or other particles of high energy.

A method of obtaining fire resistant discharges in dense gases (Crooks A.A., A.M. Razhev ArF Excimer laser with an energy of 0.5 j on the basis of the buffer gas. - Quantum electronics. 1997. 24. No. 8. S-687), namely, that between the first electrode and the second electrode, which form the main bit period, carry out the pre-ionization gas, then ignite the main discharge between the first electrode and the second electrode, while the preionization mode use photons from the auxiliary discharges that form simultaneously in the form of sparks between the rod electrodes by feeding on the rod electrodes of the high voltage pulse. Stick electrodes are placed in one row on each of two separate, elongated along the basis of the aqueous discharge dielectric plates, which are placed on two sides on the side and in the vicinity of the main discharge gap in a single gas-filled chamber with the main discharge gap. The main discharge between the first electrode and the second electrode are lit by filing on the first electrode and the second electrode of the second high-voltage pulse with a certain experimentally optimal time delay relative to the auxiliary bits.

The disadvantages of the method. Not a high stability of the main discharge to the creation of sparks, due to the low efficiency of gas preionization mode from the spark discharges. This limits the energy deposition in the main discharge and impact, such as lasers, on the output parameters of laser radiation. The life of the lasers excited by this method is limited to destruction (burning) of the electrodes of the spark gaps. In addition, the products of burning of the spark electrodes polluting gas that requires changing the gas in the main discharge gap.

A device (Crooks A.A., A.M. Razhev ArF Excimer laser with an energy of 0.5 j on the basis of the buffer gas. - Quantum electronics. 1997. 24. No. 8. S-687)that implements this method for excimer lasers, containing the first electrode and the second electrode, which form a main discharge gap, a source for pre-ionization of the gas in the main discharge gap and pulsed high voltage power supply, the source for pre-ionization of the gas in the main discharge gap are in the form spark gaps. Spark gaps do rod electrodes, which are placed in one row on each of two separate, elongated along the main discharge dielectric plates (this device is 45 pieces on each of the plates). The dielectric plate placed on two sides on the side and in the vicinity of the main discharge gap in a single gas-filled chamber with the main discharge gap. Spark gaps include interconnected in parallel or in series with the main discharge gap side of the first electrode. In parallel with the main bit interval additionally connect the unit aggravating tanks. Pulsed high voltage power supply connect the negative to the rod electrodes not connected to the first electrode of the discharge gap, and a plus to the second electrode of the main discharge gap. An electrical supply provides the ignition of the main discharge regarding discharges to the preionization mode gas in the main discharge gap with the optimal delay (this device is 170 NS).

Such devices are widely used for technological excimer lasers require a high repetition rate of the pulse is Sov which is achieved by high-speed gas flow, to several tens of m/s across the main discharge gap and needs to reduce the width of the main discharge along the gas flow to a value of ˜1 mm

The disadvantages of such devices. Not a high stability of the main discharge to the creation of sparks, due to the low efficiency of gas preionization mode from spark discharges, due to the remoteness of their location relative to the main discharge gap. Because of this, the efficiency of the preionization mode additionally decreases with increasing width of the main discharge, which does not allow to bring the lasers with a large volume. The instability of the main discharge is particularly evident at high pulse repetition rate. The life of the lasers with this device is limited by the destruction (burning) of the electrodes of the spark gaps. In addition, the products of burning of the spark electrodes polluting gas that requires additional speed gas flow.

A device (Andramanov AV, Kabaev S.A., Saginaw BV and other Compact XeF laser with a pulse frequency of 4 kHz and multiple-bit interval. - Quantum electronics. 2005. T.35. No. 4. S-315) for excimer laser spark pre-ionization to obtain fire resistant discharges in dense gases, in which additionally to improve the stability of the main discharge p is ubegayut to the longitudinal (along the optical axis of the laser) pairwise partitioning the first electrode and the second electrode of the main discharge gap (this device - 25 sections in increments of 10 mm) with capacitive-inductive decoupling between the sections, which further complicates the device.

The stability of the main discharge with such a device increases, but remains relatively high due to the low efficiency of gas preionization mode from spark discharges, due to the remoteness of their location relative to the main discharge gap. The life of the lasers with this device is also limited by the destruction (burning) of the electrodes of the spark gaps, and the products of burning of the spark electrodes polluting gas that requires additional speed pumping.

The closest technical solution to the proposed method is the method of obtaining fire resistant discharges in dense gases (Bychkov SCI, Konovalov, I.N., Tarasenko V.F. Laser in a mixture of Ar-Xe-NF3with the discharge stable short-pulse electron beam. - Quantum electronics. 1979. V.6. No. 5. S-1009), namely, that between the first electrode and the second electrode, which form the main bit period, carry out the pre-ionization of the gas and ignite the main discharge between the first electrode and the second electrode by feeding high-voltage pulse minus on the first electrode and a plus on the second electrode, while the gas preionization mode uses a relativistic electron is ucok (hundreds of Kev), which is formed in a separate vacuum chamber using a standard accelerator technology and sent to the main bit interval in the gas-filled chamber through the foil, which serves as the first electrode for the main discharge. Main discharge light by feeding on the first electrode and the second electrode of the high voltage pulse simultaneously with the current of the electron beam.

A device (Bychkov SCI, Konovalov, I.N., Tarasenko V.F. Laser in a mixture of Ar-Xe-NF3with the discharge, stable short-pulse electron beam. - Quantum electronics. 1979. V.6. No. 5. S-1009)that implements this method for excimer lasers, containing the first electrode and the second electrode, which form a main discharge gap, a source for pre-ionization of the gas in the main discharge gap and a high-voltage pulse power source, and the source for pre-ionization of the gas in the main discharge gap is made in the form of a conventional electron accelerator in a separate vacuum chamber. The vacuum chamber is connected through the foil (this device is of a thickness of 25 μm) with gas-filled chamber of the main discharge gap. Foil is used for penetration of the electron beam in the main discharge gap and as the first electrode for the main discharge. Pulse Vysokomol the private power source connect minus to the first electrode and the advantage to the second electrode of the main discharge gap. The electron accelerator is used mnogoseriynyy cathode operating on the field and explosive emission of electrons.

The disadvantages of this method of producing fire resistant discharges in dense gases and devices for its implementation are as follows. Required system pumping gas in the vacuum chamber of the electron accelerator, providing a high vacuum therein. High energy electron beam, which is necessary for the passage of electrons through the foil with low energy losses, requires the involvement of sophisticated machinery generators pulse voltages in the hundreds of kV and protect personnel from associated x-ray radiation. At lower electron energy (<100 Kev) it is absorbed by the foil, which will lead to its destruction. Small utilization of electron energy for ionization of the gas, due to the weak interaction of high-energy electrons with gas, which requires increasing the density of electrons in the beam to provide the required degree of gas preionization mode. The edge of the cathode of the electron accelerator burn, and the lifetime of the accelerator is reduced. In addition, the products of the sputtering cathode of the electron accelerator, break the vacuum, and spray products must be removed from the vacuum chamber of the accelerator during the time between pulses, which limits the repetition rate of the pulses of the s of the accelerator. Accidentally created a spark in the main discharge gap can destroy the foil, which will lead to the exit of the electron accelerator down, due to the occurrence of a high current arc discharge in a depressurized vacuum chamber of the accelerator with great destruction of the electrodes of the accelerator. The device as a whole is very complex, cumbersome and unable to work with a high pulse frequency. Because of these disadvantages of the method and the device for its implementation are not widely used and are used in unique devices lasers with a large amount of excitement.

The technical result of the invention is to improve the stability of the main discharge due to more effective preionization mode gas in the main discharge gap from the source of the preionization mode, located in the main discharge volume, it does not require any system pumping gas (no vacuum chamber), does not require the involvement of sophisticated machinery generators pulse voltages in the hundreds of kV and protect personnel from associated x-ray emission (used low-voltage electron beam), the system low voltage preionization mode used in the invention does not introduce additional contaminants in the gas. The achieved stability of the main discharge ru is La in a much more simple, compared to existing devices, to increase the specific energy delivery and power in the main discharge. The service life is higher than in the known devices, including the most widely used devices with spark pre-ionization, due to the lack of sources of gas preionization mode processes leading to the destruction of the electrodes in them.

The technical result of the proposed method of obtaining fire resistant discharges in dense gases is achieved in that between the first electrode and the second electrode, which form the main bit period, carry out the pre-ionization of the gas and ignite the main discharge between the first electrode and the second electrode, by applying a high voltage pulse minus on the first electrode and a plus on the second electrode, the pre-ionization of the gas is performed with the use of slow-electrons beam of, photons, and electrons of the plasma, which is obtained directly in the main discharge volume, and the slow-electrons beam of photons and electrons of the plasma created with the help of the barrier open discharge, feeding high-voltage pulse between the first electrode is made in the form of a grid, which is placed on a dielectric surface, and an additional electrode, which is disposed on the opposite side of the dielectric, and the main river which would be loaded on the kindle not before ignition barrier open discharge, and outdoor barrier discharge and the main discharge light in a single gas-filled chamber.

The stability of the main discharge increases with the voltage barrier open burning category.

The technical result is achieved in that in the apparatus for producing fire resistant discharges in dense gases containing the first electrode and the second electrode, which form a main discharge gap, a pulsed high voltage power supply, and the first electrode is made in the form of a grid and is located on a dielectric surface, on the opposite side of which is placed an additional electrode, and a pulsed high voltage power supply connected to minus net first electrode and a plus to the second electrode and is used for ignition of the main discharge, additional high-voltage pulse power source for barrier open discharge connected by a net plus to the first electrode and the minus sign to the additional electrode, and net the first electrode, the second electrode, the auxiliary electrode and the dielectric is placed in a gas-filled chamber.

In addition, the technical result is achieved in that in the apparatus for producing fire resistant discharges in dense gases containing the first electrode and the second electrode, which form the main bit is romeralo, high-voltage pulse power source, and the first electrode is made in the form of a grid and is located on a dielectric surface, on the opposite side of which is placed an additional electrode, and a pulsed high voltage power supply is connected less to the additional electrode, and a plus to the second electrode, in addition to connected two serially connected capacitor or a block of series-connected capacitors, evenly distributed along the main discharge gap, the average common point which is connected to the net the first electrode, and netted the first electrode, the second electrode, the auxiliary electrode and the dielectric is placed in a gas-filled chamber.

In addition, the technical result is achieved in that in the apparatus for producing fire resistant discharges in dense gases containing the first electrode and the second electrode, which form a main discharge gap, a pulsed high voltage power supply, and the first electrode is made in the form of a grid and is located on a dielectric surface, on the opposite side of which is placed an additional electrode, and a pulsed high voltage power supply connected to minus net first electrode and a plus to the second electrode and the additional is lectrode, and net the first electrode, the second electrode, the auxiliary electrode and the dielectric is placed in a gas-filled chamber.

The essence of the proposed invention is illustrated in the following description and the accompanying drawings.

Figure 1 shows a diagram of the proposed device with the planar arrangement of the electrodes for barrier open discharge and the main discharge with a separate high-voltage pulse power sources for them. Figure 2 shows a variant of the proposed device with a coaxial arrangement of the electrodes for barrier open discharge and the circuit parameter measurements barrier open discharge and the main discharge with a separate pulsed high voltage power supply barrier open discharge and the main discharge. Figure 3 shows examples of waveforms of voltage and current of the main discharge in a mixture of He:Ar:F2=80:20:0.3 pressure p=2.5 ATM for the device presented in figure 2. Figure 4 shows a variant of the proposed device with a coaxial arrangement of the electrodes barrier for open discharge, powered by a voltage pulse with the changed polarity of the total with the main discharge high-voltage pulse power source, and circuit parameter measurements both places. Figure 3 shows examples of waveforms of voltages and currents is arenoso open discharge and the main discharge in a mixture of He:Ar:F 2=80:20:0.3 pressure p=3 ATM for the device presented in figure 4.

In the drawings, showing: 1 - net the first electrode; 2 - the second electrode; 3 - main discharge gap (the area of the main discharge); 4 - oxide; 5 - additional electrode; 6 - arrow marks the direction of propagation of the electron beam; 7 and 8 - pulse high-voltage power sources. They are used for ignition barrier open discharge and the main discharge; 9 - part device in an enlarged scale; 10 - plus signs shown symbolically positive space charge in the region of cathode fall potential; And - the size of the holes in the mesh first electrode; R1, R2- the resistive voltage divider for measuring the pulse voltage of the main discharge; R3- resistance measurement current pulse main discharge; R4, R5- the resistive voltage divider for measuring pulse voltage barrier open discharge; R6- resistance measurement current pulse barrier open discharge; 11, 12 - waveforms of voltage pulses and current for the main discharge; τ - the time (the relevant portion of the waveform of the current pulse for the main discharge shaded) effective energy input in the main discharge; UMD, IMD- voltage and current for the main discharge is; 13 is pulsed high voltage power supply. It is used for ignition barrier open discharge and the main discharge; R7, R8- the resistive voltage divider for measuring a single voltage impulse barrier open discharge and the main discharge; UMD,BD- single voltage barrier for open discharge and the main discharge; IBDthe current barrier for open discharge; 14 - the single waveform of the pulse voltage for the barrier open discharge and the main discharge; 15 - the waveform of the current pulse for the barrier open discharge.

Consider qualitatively, through assessments, physics of the processes relating to the proposed invention.

The essence of the proposed method of producing fire resistant discharges in dense gases consider the example of operation of the proposed device for carrying out the method and is depicted in figure 1, paying attention to possible applications of the discharge, primarily for excimer lasers with high pulse repetition rate.

The basis of the method is more effective pre-ionization of the gas in the main discharge gap, which is provided by the slow-electrons beam of, photons and electrons of the plasma, obtained directly in the volume of the main discharge at the cathode. The source of this preionization mode is the outdoor barrier discharge, which is used in the proposed device implementing this method.

To tens of Torr in the usual open discharge with metal electrodes and bit interval d<1 mm effectively formed electron beams extracted through the mesh anode. The electron energy wecorresponds applied to the bit period of the voltage U:

we≈eU, (1)

where e is the electron charge, if d<l, or d˜l - length region of the cathode potential drop. If the mesh electrode used as the cathode of the main discharge, the electron beam that have been released over the net, picked up the main discharge, providing an overlap formed in the main discharge electron avalanches and thereby stabilizing the main discharge. From the open discharge, in addition, is illuminated by photons of the main discharge gap. However, the pressure excimer lasers p=1-3 ATM, which requires to increase the working pressure open discharge 2 orders. Discuss what problems arise for open discharge during the transition to high pressures, for example helium, and in conditions of abnormal glow discharge, which is rapidly formed in the discharge for the considered conditions of high pressure.

The length of the region of cathode fall of potential - l from the formula for the parameter of similarity:

PHel=0.48 Torr·cm (2)

where pHe- pressure helium, for pNot=3 ATM will be only 2 microns. To organize a bit interval d˜l to the energy of the electrons of the beam corresponded to (1) is applied to the bit period of the voltage U, is difficult. If you d≫l, then the energy of the electrons in the beam will be determined by the value applied to the bit period of the voltage U (1), and the cathode potential drop Ucfthat is, for example, at a supply voltage of 20 kV can be only 200 due to the "smearing" U along the entire length of d, mostly in the area of the cathode drop potential: we≈eUcf≪U.

For our purpose high energy electron beam optional, but the penetration depth L in a gas of electrons with energy of 200 eV, is formed in the region of cathode fall of potential at pNot=3 ATM, according to the formula, valid for Ucf=100-104In:

pHeL=6.5·10-4(eUcf)1.54Torr·cm (3)

where eUcftaken in eV, small - L=10 μm. For electrons for mesh electrode length d must be also too small d<L=10 ám.

In addition, for Ucf=200, pNot=3 ATM field at the cathode surface:

Ec=2Ucf/l, (4)

(relies typical, close to linear, the decay of the field in the region of cathode fall of potential in the direction from the cathode) will be Ec=2·10 V/cm and the discharge without cathode spots will remain less than 10 NS. Normal discharge can be sustained and with cathode spots, but for small d the spot just block the gap d and there will be a spark.

Thus, conventional outdoor discharge unsuitable for our purpose.

Let's see how the above problems are solved with the barrier open category.

Conventional barrier discharge with one or two electrodes covered with a dielectric, has a high resistance to sparks. But, in the traditional version of the device for barrier open discharge, which is formed in the gap d between the surface of the dielectric covering the metal cathode barrier open discharge, and a mesh anode barrier open discharge, these problems remain the same.

To solve the above problems managed in the barrier open discharge figure 1, where the mesh first electrode 1 (anode barrier for open discharge) is located directly on the surface of the dielectric - 4.

Here, the surface discharge on the insulator within the holes And difficult, due to the indemnification of the tangential component of the electric field due to the proximity of the jumpers mesh of the first electrode 1.

Next. Net first electrode - 1 escapes the strong penetration of the field into C the net first electrode 1. Positive charge - 10 in the region of cathode fall of potential additional screens field. In the lines of force of the electric field perpendicular to the surface of the dielectric - 4, a short way back on jumpers mesh of the first electrode 1, which reduces bleeding" U and increases the cathode fall of potential in the area which are always performed "runaway" electrons in the beam.

Finally here, the current random heterogeneity quickly reduces the local electric field, charging the surface of the dielectric - 4 size in the same hole and thereby prevents the development of weak inhomogeneity in spark (an effect similar to the partitioning bit).

With such a barrier open discharge device in which the first mesh electrode - 1 had holes And=0.17 mm, the obtained electron beams with energies up to 10 Kev at atmospheric pressure helium. To increase the duration of the current pulse, which is determined by the charging time of the dielectric - 4 discharge current, used dielectric with a high dielectric constant ε≈1000 (ceramic capacitor). For our purpose the long duration of barrier open discharge optional and can be used, for example, glass (ε≈10), which was used in the experiments with the proposed device, is whether conventional ceramics.

The size of the holes in the mesh first electrode 1 defines the course of force lines of the electric field with jumpers mesh of the first electrode 1 to the surface of the dielectric - 4. Their average length, we can take effective length of the discharge gap dBDroughly - dBD˜A/2. The smaller A, the shorter the lines of force, less "smearing" U, higher cathode fall potential and the electron energy of the beam.

Rate if "spreading" U, on the basis of measurements in experiments with normal discharge between the metal electrodes in the conditions: pNot=100 Torr, d=7.4 mm, U=3.3 kV, - when, according to (2) l is 1/157 part d. "Spreading" U turned out to be not so great: Ucf≈0.5U=1.65 kV. For pNot=3 ATM, when l=2·10-3mm, Ucf≈0.5U if dBD=l·157≈0.3 mm or A=0.6 mm

Net first electrode 1 can be obtained on the surface of the dielectric - 4, for example, sputtering metal thickness of several microns. But for our purpose, when the net first electrode 1 serves as a cathode for the main discharge, a thin layer of metal mesh of the first electrode gradually be dissolved in the process of cathode sputtering. Therefore, acceptable for the net thickness of the first electrode 1 can be taken δ=0.1-0.2 mm For the above case with the energy of the electrons eUcf=1.65 Kev, the depth of yproniknovenie in the gas according to the formula (3) for p Not=3 ATM will be L=0.26 mm, i.e. the beam will go beyond the net thickness of the first electrode 1 if δ<0.26 mm, which is quite acceptable.

For the actual conditions of discharge boundaries given estimates can be refined by experience. Additional sources of electron preionization mode for the main area of the discharge - 3 are produced by photoionization of the gas and the electrons of the plasma barrier open discharge, which are extracted field main discharge as equipotential bonding surface of the dielectric 4 and the mesh of the first electrode 1 in the process of charging the surface of the insulator 4 in the area of the holes in the mesh first electrode 1. Provides the greatest stability of the main discharge optimal delayed ignition pulse from the high voltage power source - 8 connected to the net the first electrode 1 and second electrode 2 main discharge, a relatively ignition barrier open discharge from the high-voltage pulse power source 7, and the plug connects to net the first electrode 1 and the negative to the additional electrode 5, is chosen empirically and depends on the composition of the gas being used.

The proposed method of producing fire resistant discharges in dense gases suggests another mode barrier open discharge changed with the second polarity of the power supply, when the net first electrode 1 serves as a cathode barrier open discharge, and the additional electrode 5 to the anode barrier open discharge. In this case, the electron beam injected into the main discharge region - 3, is formed in the region of the cathode potential drop part of the surface mesh of the first electrode 1 facing the main discharge. Additionally, the electron preionization mode for the main discharge are electrons from fotomodelli of the field barrier open discharge from the plasma formed in the cavities of the holes in the mesh first electrode 1 as a result of interaction in them colliding electron beams from the inner surfaces of lintels grid gas (as in a hollow cathode). The stability of the barrier open discharge against sparks here also saved by reducing the local strength of the electric field in the charging current of weak inhomogeneity of the surface of the dielectric - 4, limited nearby the place of occurrence of the heterogeneity of the mesh holes of the first electrode 1. Here also provides the greatest stability of the main discharge optimal delayed ignition pulse from the high voltage power source - 8 connected to the net the first electrode 1 and the second electron is kind - 2 main discharge, a relatively ignition barrier open discharge from the other high-voltage pulse power source 7, and connected by a net minus to the first electrode 1 and a plus to the additional electrode 5, is chosen empirically and depends on the composition of the gas being used.

Figure 1 shows the schematic of the proposed device that implements the proposed method of producing fire resistant discharges in dense gases, with planar, as in figure 2 version of the proposed device with a coaxial arrangement of the electrodes barrier for open discharge, both devices with a single pulse high voltage power supply for barrier open discharge and the main discharge.

The device comprises: a mesh of the first electrode 1 and second electrode 2, which form a main discharge gap (the area of the main discharge) - 3. Net first electrode 1 is located on the surface of the dielectric - 4, on the opposite side of which is the additional electrode 5. All these elements are placed in a single chamber. In addition, the device contains a high-voltage pulse power supply 7 for barrier open discharge, which is connected by a net plus to the first electrode 1 and the minus sign to the additional electrode 5 and a separate high-voltage pulse source p is Tania - 8 for the main discharge, which is connected to minus mesh to the first electrode 1 and positive for the second electrode 2.

The device operates as follows. The camera fills the working gas. By submitting a voltage pulse from a pulsed high voltage power supply - 7 plus on the net the first electrode 1 and the negative auxiliary electrode is 5 light outdoor barrier discharge, electron beam, photons and electrons of the plasma barrier open discharge carries out the pre-ionization of the gas in the main discharge gap - 3. Then through providing the greatest resistance main discharge optimal delay ignite the main discharge by the pulse voltage from the high-voltage pulse power source - 8 connected by a net minus to the first electrode 1 and positive for the second electrode 2 main discharge.

The device of figure 2, with a coaxial arrangement of the electrodes for barrier open discharge and a separate high-voltage pulse power supplies for barrier open discharge and the main discharge was tested in experiments with a standard mixture of ArF-laser: No:Ar:F2=80:20:0.3 pressure p=2.5 ATM. The volume occupied by the main discharge was V=dMD×a×b≈8×1×30=240 mm3where dMD- the distance between the mesh the first electrode 1 and second electrode 2, and the width of the main discharge was estimated visually on the main glow discharge), b is the length of the main discharge. Net first electrode 1 (flat stainless steel mesh: geometric transparency - 0.5, holes And=1 mm, thickness δ=0.2 mm) tightly wrap around a glass tube with a diameter of 5 mm In a tube with a hole diameter of 3 mm was inserted tightly to the wall of the tube an additional electrode 5 of metal foil. For measurements of voltage pulses barrier open discharge and the main discharge used resistive voltage dividers R1, R2and R4, R5. For measurement of current pulses barrier open discharge and the main discharge used resistance R6and R3.

The voltage pulse for the main discharge was filed with adjustable delay tdrelative to the beginning of the pulse voltage for the barrier open discharge. In terms of experience: a mixture of He:Ar:F2=80:20:0.3 pressure p=2.5 ATM, received waveforms of voltage pulses UMD- 11 and the current IMD- 12 main discharge are presented in figure 3. The optimal delay tdcorresponded to the end of the first half of the current barrier open discharge and amounted to 60 NS. Barrier outdoor discharge was so weak that in the absence of primary rasra is not caused glow gas visible. The amplitude values of voltage and current on the electrode barrier open discharge amounted to: UBD=11 kV (duration front - 35 NS), IBD=12 A. the Actual values of voltage and current of the barrier open discharge less registered UBD, IBD. During the course of the barrier open discharge in the charging of the dielectric surface - 4 not occupied by the jumpers grid is in the process of equalization of the potential of this part of the surface of the insulator 4 and the mesh of the first electrode 1, which reduces the real value of the voltage at the barrier open discharge. Registered current barrier open discharge additionally includes a current charging the surface of the dielectric - 4, occupied jumpers net first electron - 1. To improve the efficiency of the preionization mode should be used more steep front ubd.

The deposition of energy in a stable main discharge defined by the waveform UMD, IMD, figure 3, for the period of time the most effective deposition τ=12 NS (the relevant portion of the waveform of the current pulse for the main discharge shaded) amounted to 2.5 j/cm3when the average power P=210 MW/cm3that is one order higher than in known devices.

With the device, in which, in contrast to the presented in figure 2, used tiny pulsed high voltage power supply, which was connected less to the additional electrode 5 and a plus to the second electrode 2 and, additionally, to two series-connected capacitors, the average common point which is connected to the grid of the first electrode 1 (capacitive voltage divider for high voltage power barrier open discharge and the main discharge)were obtained waveforms of voltage and current for the main discharge in a mixture of He:Ar:F2=80:20:0.3 pressure p=3 ATM, almost coincident with the waveform of the voltage pulses - 14 and DC - 12 main discharge are presented in figure 5. The deposition of energy in a stable main discharge defined by this received waveform, for a period of time the most effective deposition τ=18 NS was 2 j/cm3when the average power P=110 MW/cm3. The capacitance of the capacitor connected to the net the first electrode 1 and the additional electrode 5 (CBD≈4.7 nF) on the order exceeded the capacity of the condenser connected to the grid of the first electrode 1 and second electrode 2 (CBD≈0.4 nF). The energy consumption for outdoor barrier discharge was ˜10%, because the capacitor CBD≈4.7 nF was charged to a voltage substantially lower, supplied from the high-voltage pulse power source, and the energy stored in the capacitor increases the AC square voltage of the charge.

Figure 4 shows a variant of the proposed device with a coaxial arrangement of the electrodes barrier for open discharge, zaspivaymo pulse voltage with the changed polarity of the total with the main discharge high-voltage pulse power source, and circuit parameter measurements both places.

The device comprises: a mesh of the first electrode 1 and second electrode 2, which form a main discharge gap (the area of the main discharge) - 3. Net first electrode 1 is located on the surface of the dielectric - 4, on the opposite side of which is the additional electrode 5. All these elements are placed in a single chamber. In addition, the device contains a high-voltage pulse power supply - 13 barrier for open discharge and the main discharge, which is connected plus to the additional electrode 5 and second electrode 2, and a net minus to the first electrode 1.

The device operates as follows. The camera fills the working gas. With the filing of the voltage pulse from the pulsed high voltage power supply - 13 plus additional electrode 5 and second electrode 2, and a net minus to the first electrode 1 first ignited outdoor barrier discharge, then beginning with the effective gas preionization mode in the main bit prom is gutke - 3 electron beam, photons and electrons of the plasma barrier open discharge, ignited the discharge in the main discharge gap - 3.

The device, figure 4, with a coaxial arrangement of the electrodes for barrier open discharge and with the changed polarity of the power barrier open discharge from a single high-voltage pulse power source for barrier open discharge and the main discharge was tested in experiments with a standard mixture of ArF-laser: He:Ar:F2=80:20:0.3 pressure p=3 ATM. Used the same as in the previous experiments the discharge chamber and the items in it. The volume occupied by the main discharge was V=dMD×a×b≈8×1×30=240 mm3. Net first electrode 1 (flat stainless steel mesh: geometric transparency - 0.5, holes And=1 mm, thickness δ=0.2 mm) tightly wrapped around a glass tube with a diameter of 5 mm In a tube with a hole diameter of 3 mm is inserted tightly to the wall of the tube an additional electrode 5 of metal foil. For measurements of a single voltage pulse barrier open discharge and the main discharge used a resistive voltage divider R7, R8. For measurement of current pulses barrier open discharge and the main discharge used resistance R6and R3.

In terms of experience: a mixture of He:ArF 2=80:20:0.3 pressure p=3 ATM, is obtained, figure 5, waveform single pulse voltage barrier open discharge and the main discharge UMD,BD14, the current IMD- 12 main discharge current and the barrier open discharge IBD- 15. As in the previous experiments, the actual values of voltage and current of the barrier open discharge less registered UMD, BD, IBD. During the course of the barrier open discharge in the charging of the dielectric surface not occupied by the jumpers grid is in the process of equalization of the potential of this part of the surface of the insulator 4 and the mesh of the first electrode 1, which reduces the real value of the voltage at the barrier open discharge. Registered current barrier open discharge additionally includes a current charging the surface of the dielectric - 4 busy intersections mesh of the first electrode 1.

Automatic ignition barrier open discharge before the main discharge is explained by the following circumstance. In the normal discharge gap d with metal electrodes under the application of a constant voltage discharge ignition (electric breakdown of the discharge gap) occurs when the voltage Ubdepending on the value of the parameter pd - Paschen curve. The curve has a minimum, for example, for helium U b)min=220 V at pHed≈4 Torr·see, and then linearly increases with pd. For the average and conditional length of the discharge gap dBD˜A/2=0.5 mm barrier open discharge and the gap length dMD=8 mm, main discharge voltage ignition barrier open discharge will be in the dMD/dBD=16 times lower than the ignition voltage of the main discharge. Actually, this ratio will be even higher, because between jumpers mesh of the first electrode 1 and the surface of the dielectric - 4, limited by the mesh holes of the first electrode 1, there is a far smaller development path barrier open discharge and he started there will initiate a discharge in the adjacent parts of the surface of the dielectric - 4. Pulse ignition barrier open discharge will occur at a higher Ubthan when applying a DC voltage, and with a time delay relative to the beginning of the voltage pulse. The higher the slew rate of the applied voltage (steeper leading edge of the applied voltage), the more pressure will occur ignition barrier open discharge. It follows that to increase the efficiency of the preionization mode in the main category should be used more steep front impulse voltage barrier open discharge. When the canopy of the front ignition barrier on the indoor discharge will occur at a smaller value of U band after ignition in the charging of the dielectric surface - 4 current barrier open discharge it will remain low voltage burning, which will reduce the effectiveness of the preionization mode.

Thanks 2 times more steep front impulse UMD, BD, figure 5 than in the experiments with the device presented in figure 2 (where the duration of the leading edge for UBDwas 35 NS), the pre-ionization was so high that the main discharge was ignited almost simultaneously with the filing of the voltage pulse (compare with waveforms figure 3). A similar pattern was observed in the experiments with the capacitive voltage divider barrier for open discharge and the main discharge. In other words, in these cases, the pre-ionization provides the ignition of the main discharge in the form of sustained discharge.

With this device, the deposition of energy in a stable main discharge defined by the waveform UMD, BD, IMD, figure 3, for the period of time the most effective deposition τ=18 NS (the relevant portion of the waveform of the current pulse for the main discharge shaded) was 2 j/cm3when the average power P=110 MW/cm3.

The device, which was used the same polarity power supply to the barrier open discharge and the main discharge, and the device performance is allenna figure 4, but with a separate pulsed high voltage power supply for barrier open discharge and the main discharge was obtained by the same stability of the main discharge.

1. The method of obtaining fire resistant discharges in dense gases, namely, that between the first electrode and the second electrode, which form the main bit period, carry out the pre-ionization of the gas and ignite the main discharge between the first electrode and the second electrode, by applying a high voltage pulse minus on the first electrode and a plus on the second electrode, characterized in that the pre-ionization of the gas is performed by the slow-electrons beam of, photons and electrons of the plasma, which is obtained directly in the main discharge volume, and the slow-electrons beam of photons and electrons of the plasma created with the help of the barrier open discharge, applying a high voltage pulse between the first electrode made in the form of a grid, which is placed on a dielectric surface, and an additional electrode, which is disposed on the opposite side of the dielectric, and the main discharge is lit until the ignition barrier open discharge, and outdoor barrier discharge and the main discharge light in a single gas-filled chamber.

2. The device for producing the fire resistant rasra is in dense gases containing the first electrode and the second electrode, which form a main discharge gap, a pulsed high voltage power supply, wherein the first electrode is made in the form of a grid and is located on a dielectric surface, on the opposite side of which is placed an additional electrode, and a pulsed high voltage power supply connected to minus net first electrode and a plus to the second electrode and is used for ignition of the main discharge, additional high-voltage pulse power source for barrier open discharge connected by a net plus to the first electrode and the minus sign to the additional electrode, and netted the first electrode, the second electrode, the auxiliary electrode and the dielectric posted in a single gas-filled chamber.

3. Apparatus for producing fire resistant discharges in dense gases containing the first electrode and the second electrode, which form a main discharge gap, a pulsed high voltage power supply, wherein the first electrode is made in the form of a grid and is located on a dielectric surface, on the opposite side of which is placed an additional electrode, and a pulsed high voltage power supply is connected less to the additional electrode, and a plus to the second electrode is, additionally connected to two serially connected capacitor or a block of series-connected capacitors, evenly distributed along the main discharge gap, the average total point which is connected to the net the first electrode, and netted the first electrode, the second electrode, the auxiliary electrode and the dielectric is placed in a gas-filled chamber.

4. Apparatus for producing fire resistant discharges in dense gases containing the first electrode and the second electrode, which form a main discharge gap, a pulsed high voltage power supply, wherein the first electrode is made in the form of a grid and is located on a dielectric surface, on the opposite side of which is placed an additional electrode, and a pulsed high voltage power supply connected to minus net first electrode and a plus to the second electrode and the additional electrode, and netted the first electrode, the second electrode, the auxiliary electrode and the dielectric is placed in a gas-filled chamber.



 

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