RU17101U1 - ELECTRODYNAMIC PLASMA VOLTAGE PULSE FORMER - Google Patents

Description

Electrodynamic Plasma Shaper

voltage pulses

The utility model relates to powerful pulsed electrophysics and can be used to create pulse-forming devices for terawatt power sources, to power Z-pinch loads, high-current accelerators of charged particles, etc.

Known plasma shaper of voltage pulses I {Pavlovsky A.I. et al., Explosive breaker of pulsed current, and.with. No. 490381, H 01 H 39/00, publ. BI No. 39, 1976). The device is based on the destruction of the plasma channel on a ribbed barrier by explosive energy (EX). The plasma-forming element is made in the form of a dielectric film with a sprayed layer of metal connecting the current leads. The plasma forming element is separated from the ribbed barrier by a small gap. Under the action of the explosion products, the channel plasma is displaced into the grooves of the ribbed barrier, and the conducting channel is repeatedly broken. Due to the high resistance of the explosion products through which current flows after a channel breaks, the current decreases rapidly. The development of secondary breakdown with increasing voltage arising at the time of channel rupture is hindered by the high density of explosion products.

The disadvantage of this plasma voltage driver is the limitation in power and voltage of the pulse transmitted to the load, associated with the use of explosives and limitation

 H 77/10

acceleration of plasma.

Closest to the claimed device is an electrodynamic plasma shaper of voltage pulses 2 {Silin V.P., Bystroe M.N., High-current high-speed switch, a.s. No. 497652, H 01 H 77/06, publ. BI No. 48, 1975). The electrodynamic plasma voltage pulse generator comprises a current pulse source, a pair of current leads, a destructible element and a ribbed barrier with ribs facing the destructible element. The destructible element is made in the form of a low-resistance foil, the mass and cross section of which are selected from the heating conditions during switching to the melting point. The foil moves to the ribbed barrier in an electrodynamic way under the influence of magnetic pressure. The foil is separated from the ribbed barrier by a small gap.

The disadvantage of this shaper is the limitation in power and voltage of the generated pulse transmitted to the load, associated with the parameters of the foil destructible element.

When creating this utility model, the task of substantiating the creation of a sufficiently reliable pulse shaper for sources of terawatt power was solved.

The technical result of the proposed solution is to increase the power and voltage transmitted to the load of the generated pulse.

The indicated technical result is achieved in that, in comparison with the known electrodynamic plasma voltage pulse shaper containing a current pulse source, current leads, a destructible element and ribbed obstruction with ribs facing the destructible element, the new one is that the shaper additionally contains an accelerating chamber crushable

 3

iC / l-f

the element is made plasma-forming, the edges of the barrier are made of the same or different height with the formation of the profile of the outer surface, repeating the profile of the plasma shell when it approaches the ribbed barrier.

The operating principle of the proposed shaper is based on the accumulation of current energy in an inductive energy storage device (Pffl3), whose role is played by a closed loop: a current pulse source — one of the current leads — a plasma sheath formed in the interelectrode gap by one or more plasma sources — another current lead — a current pulse source , acceleration of the plasma shell by the Ampere force increasing in time, decomposition of the plasma shell upon impact on a ribbed barrier, which leads to a sharp increase in resistance and transmitting at the same time the stored energy from the load RSHE.

The amplitude of the voltage pulse in the load is higher, the shorter the duration of the opening process. To reduce the duration of the opening process, it is necessary to achieve the highest speed of the plasma shell when it approaches a ribbed barrier, as well as the simultaneous destruction of various parts of the plasma shell.

Since the Ampere force is proportional to the square of the current in the circuit, the larger the accumulated current in the INE, the greater the final speed of the plasma jumper. Thus, the proposed driver is the more efficient the more current it opens.

It is known that in the process of plasma electrodynamic acceleration, its profile is a curvilinear surface convex in the direction of its movement, and the part of the plasma shell adjacent to the internal current guide usually moves faster than the adjacent

to the external lead, part of the sheath 3 (Bernard A., Cloth R., Conrads H. et al, The dense plasma focus - a high intensity neuton source, Nuclear Instrum. and Meth., 1977, v. 145, p. 191). This circumstance allows us to assert that by performing the edges of the barrier of the same or different height with the formation of the profile of the outer surface, repeating the profile of the plasma shell when it approaches the ribbed barrier, it is possible to achieve simultaneous destruction of all parts of the plasma shell. This will reduce the duration of the opening process to a minimum and generate a voltage pulse in the load of maximum amplitude.

We point out that at the stage of acceleration of the plasma shell and the accumulation of current in the REM, the proposed device is similar in principle to the operation of such a known device as the plasma focus 3. Therefore, the magnitude of the accumulated current in the INE, the final velocity of the plasma shell, and the plasma concentration in it can reach the values realized in plasma tricks.

In this regard, by analogy with the plasma focus, it is advisable, but not necessary, to achieve the technical result in the proposed shaper to perform the following:

combine the functions of a high-voltage insulator and a plasma-forming insulator in the same structural element;

arrange extended INE electrodes so that one of them covers the plasma-forming insulator so that a sliding type of surface discharge is used to create the plasma, which has spatial uniformity and low breakdown voltage;

provide the gas pressure in the booster chamber, i.e. in the region of acceleration of the plasma shell equal to the gas pressure, which is usually

Jue / l- {e i

used in plasma foci (p 0.1-10 Torr), while if the gas pressure in the load is different (for example, the load is a high-current vacuum diode, p W Torr), then the ribbed dielectric barrier can hermetically separate two regions with different gas pressures ( plasma acceleration regions and load regions).

The proposed shaper eliminates the need to perform complex topology of the RFE contour in order to prevent plasma from entering the load

In FIG. 1-3 shows three examples of the structural implementation of the proposed device. These examples represent three embodiments of a pulse shaper. In FIG. 1 shows the inventive electrodynamic plasma shaper of current pulses of a plane-parallel configuration. In FIG. 2 shows the inventive device coaxial configuration with the axial movement of the plasma shell. In FIG. 3 shows the inventive device disk configuration with radially converging motion of the plasma shell.

The electrodynamic plasma voltage pulse shaper includes current leads 1 and 2, a plasma forming element 3, a ribbed barrier 4 with ribs facing the breaking element and an accelerating chamber 5. The plasma forming element is made in the form of an insulator 3, on the surface of which a plasma shell is formed. The edges of the barrier 4 are made of the same (Fig. 1) or different (Fig. 2 and Fig. 3) heights with the formation of the profile of the outer surface that repeats the profile of the plasma shell when it approaches the ribbed barrier 4. In addition, the device contains a current pulse source 6, a commutator 7 and load 8. In the figures, the arrow indicates the direction of acceleration of the plasma shell 9.

current 6 uses a capacitor bank, an explosive magnetic or explosive magnetohydrodynamic generator, which is connected through a switch 7 to the conps of two current leads 1 and 2. Between the electrodes is a high-voltage plasma-forming insulator 3 and a ribbed barrier 4 made of insulating material, which restricts the movement of the plasma shell 9. K to the opposite ends of current leads 1 and 2, load 8 is configured, which is, for example, a vacuum explosion-emission diode or a device for realizing a Z-pin cha. The acceleration chamber 5 is bounded by current leads 1 and 2, the plasma-forming insulator 3 and the dielectric ribbed barrier 4 are filled with gas, for example, neon at a pressure of 1 Torr. The area limited by current leads 1 and 2, load 8 is under pressure 10 Torr, if the load is a vacuum explosion-emission diode.

The shaper works as follows. First, the current pulse source 6 is started using the switch 7. Upon receipt of a high-voltage pulse, breakdown occurs on the surface of the plasma-forming insulator 3, which leads to the formation of a continuous plasma shell 9, then the magnetic field begins to increase and causes the plasma shell 9 to detach from the insulator 3 and its further acceleration. With the accelerated movement of the plasma shell 9, gas ionization and raking of the ionized part of the gas by the plasma shell (the so-called plasma plow mechanism) occurs, which leads to an increase in plasma concentration, an increase in its conductivity and an increase in current. When the speed of the plasma shell 9 reaches the required value, it flies on the edges of the barrier 4 and is destroyed by these edges. The plasma resistance increases in this case, the voltage between current leads 1 and 2 increases sharply and is transmitted to

f -7 /

load 8.

Here are some numerical values of physical quantities that characterize the operation of the inventive shaper:

the capacitance of the capacitor bank, in the form of which a current pulse source can be made, is 9 mF;

charging voltage of a capacitor bank - 15 kV;

power reserve of a capacitor bank - 1 MJ;

plasma concentration near the plasma-forming insulator - 10 cm;

plasma concentration when approaching the shell to the ribbed prefad 10 cm; the accumulated current in the INE is 3.5 MA;

the speed of flight of the plasma shell to the ribbed insulator - 2-10 cm / s;

plasma shell thickness -1 cm;

current opening time - 50 not;

the coefficient of exacerbation of power in the load is 10-15.

The proposed physical parameters correspond to the achieved level of technological development and are implemented in addition to the last output parameters, for example, in 4 (Filippov NV, Filippova T.I., Khytoretskaia IV et al, Megajode scale plasma focus as efficient X-ray source, Phys. Lett. A 1996, V. 211, No. 3, p. 168). Application of the proposed solution will allow you to create a device with output parameters that are not feasible in the known electrodynamic plasma voltage pulse shapers.

Claims (1)

An electrodynamic plasma voltage pulse shaper containing a current pulse source, current leads, a destructible element and a ribbed barrier with ribs facing the destructible element, characterized in that it further comprises an accelerating chamber, the destructible element is made plasma-forming, and the barrier ribs are made of the same or different height with the formation of the profile of the outer surface, repeating the profile of the plasma shell when it approaches a ribbed barrier.