DD147442A1 - TRIGGER ARRANGEMENT FOR SPREADING SPARKS - Google Patents

Abstract

The invention is applicable to the synchronous release of pulsed lasers or to the exact synchronization of Vorgerengen which are triggered by spark gaps, for example, for controlling electro-optical shutters. The aim of the invention is to have a triggerable spark gap available, in which the scattering time between application of the trigger pulse and breakthrough of the spark gap is less than 1 ns. The arrangement should be technologically easy to produce. The object is to form a trigger arrangement such that the initial charge carriers required for the initiation of the spark gap passage, generated by field emission from a suitably designed emitter, are introduced in the direction of the development of breakdown into the electrode gap on the cathode side. According to the invention, one of the electrodes has an axial bore, at the bottom of which there is a flat metal mesh. Below the metal mesh, an auxiliary electrode is arranged, which is flat in the middle and rounded at their edges. The distance of the auxiliary electrode to the metal mesh is adjustable. The auxiliary electrode consists for example of aluminum under N & ind2! -Atmosphaere.

Description

Dr, Werner Schramm Berlin, October 25, 1979

Zustellungsbevollmächtigt:

Academy of Sciences of the GDR Central Institute of Optics and Spectroscopy - Patent Office

1199 Berlin-Adlershof, Rudower Chaussee 5

Trigger arrangement for the ignition of spark gaps

Field of application of the invention

The invention relates to a trigger arrangement for the ignition of spark gaps with a time jitter below 1 ns. Such arrangements are preferably used for the synchronous triggering of pulsed lasers or for the exact synchronization of processes which are triggered by spark gaps, for example for actuating electro-optical shutters (Pockels cell, Kerr cell).

Characteristic of the known technical solutions

For more than 30 years known as trigatrons. These are spark gaps in which one of the opposing two main electrodes has a bore in which a firing pin is arranged in isolation. These trigatrons have spread times on the order of microseconds

(Lampe, W., Triggering of Generators with Wide Working Range, ETZA 83 (1962) 18, p. 591-596) · In high-pressure spark gaps, by reducing the electrode gap, scattering times can be reduced down to 20 ns (Goldenbaum, G., Hintz, E , "Pressurized trigatrons with a 1 o kV - 50 kV low jitter operating range", Proc. Of the 5th international conference on ionization phenomena in gases, Munbh 1962).

There are also a number of trigger arrangements have become known in which a sliding discharge over a semiconductor surface

(Prie, W., On the Switching Capacity and the Ignition Mechanism of a Externally Triggered Uiederdruckfunkenstrecke with Hllfsfunken in the cathode, Z. Naturforschg., 22 a (1967), pp. 1963-1974),

a ceramic surface with a high dielectric constant

(Lytkin, LK et al., Fast Impulse Spark Line for High Performance, 7ГТЭ (1978) 5, p. 123), or thin insulating layers of polyethylene, titania or alumina

(BRD-OS 2 146 427, Int.Cl. H 01 T, 3/00) triggers the spark gap.

All these solutions have in principle the same disadvantage as the ignition with a trigger pin, since first an auxiliary discharge must be ignited before the actual

breakthrough spark gap. The scattering time of such spark gaps is composed accordingly of the scattering time for the formation of the auxiliary discharge and the scattering time for the formation of the main discharge and is on the order of a few nanoseconds at best.

Object of the invention

The aim of the invention is to have available a triggerable spark gap, in which the scatter time between application of the trigger pulse and breakthrough of the spark gap is less than 1 ns. This arrangement should be easy to produce and technologically simple.

Explanation of the essence of the invention

The invention has for its object to form a trigger arrangement for igniting spark gaps such that the required for the initiation of the spark gap passage initial charge, generated by field emission from a suitably trained emitter, are introduced in the direction of the breakdown development in the electrode gap on the cathode side.

According to the invention the object is achieved by an arrangement which is formed in the manner described below. One of the main electrodes has an axial bore at the bottom of which is a flat metal mesh. Below the metal mesh, an auxiliary electrode is arranged, which is flat in the middle and rounded at their edges. The distance of the auxiliary electrode to the metal mesh is adjustable.

Preferably, the auxiliary electrode is made of a material which promotes the field emission, for example of aluminum under Np atmosphere. It can have a rough surface.

Conveniently, the high voltage trigger pulse is supplied via a coaxial cable.

embodiment

The invention will be explained in more detail below using an exemplary embodiment. The accompanying drawing shows the axial section of an inventively designed trigger assembly.

In a in the present embodiment to the outside gas-tight sealed discharge space 1, which is formed of a cylindrical Isolierstoffwand 2 and consisting of insulating end walls 3a, 3b, the two main electrodes 4, 5 are in a known V / eise by the gas pressure and the Operating voltage conditional distance compared. The main electrode 5 is formed as a hollow body and includes an axial bore 6, at the bottom of a flat metal mesh 7 is attached, for example by soldering. In the hollow electrode body, an insert 8 is introduced, for. B., wherein a sealing ring 9 ensures the gas tightness. The insert 8 receives the required for the supply of the trigger voltage coaxial cable 10 against contact and carries the auxiliary electrode 11. This consists of an emission-friendly material, eg. As aluminum, and has a roughened surface. The inner conductor 12 of the coaxial cable 10 and the auxiliary electrode 11 are connected to each other via a metallic intermediate piece 13.

This intermediate piece 13 is cast in a cast resin body 14 which is glued to the connecting flange 15 of the insert 8. When cast resin body 14 precautions are taken, for. B. in the form of annular grooves 16, 17, to ensure the dielectric strength between the metal parts electrically connected to the auxiliary electrode 11 and the metal parts connected to the main electrode 5.

The metallic outer jacket 18 of the coaxial cable 10 is electrically conductively connected to the main electrode 5 via the metallic connecting flange 15. Means are provided here, for example, a pitch thread 19 in order to set the distance between the metal mesh 7 and the auxiliary electrode 11 required for the field emission from the auxiliary electrode 11.

With the help of the trigger arrangement according to the invention, a precise triggering of switching operations with scattering times below 1 ns can be realized. For example, Fig. 3 enables the accurate synchronization of multiple nitrogen lasers and pulse gas lasers with detection means. The invention provides new technical aids for research. Advantageously, the trigger arrangement can be used for the investigation of the time resolution in dye lasers and the separation of individual pulses.

Claims (3)

invention claim 1. Trigger arrangement for ignition of spark gaps, characterized in that one of the main electrodes has an axial bore at the bottom of which is a flat metal mesh, and below the metal mesh an auxiliary electrode is arranged, which is rounded in the middle and at their edges and whose distance to the metal mesh can be adjusted. 2. Trigger arrangement according to item 1, characterized in that the auxiliary electrode consists of a material, aa $ favors the field emission, for example, aluminum under ITp atmosphere, and / or has a rough surface _β 3. Trigger arrangement according to item 1 and 2, characterized in that the high-voltage trigger pulse is supplied via a coaxial cable. Hiorzu 1 page drawings