Flow compression generator
The flow compression generator , also known as FLUX in colloquial language , is a pyrotechnic pulse generator for the one-time generation of a short and powerful electrical pulse with high instantaneous power . In combination with a vircator , which is fed by the flow compression generator, a powerful electromagnetic pulse (EMP) can be generated within a radius of a few 100 m in order to disrupt electronic devices such as radar systems or radio systems or make them permanently inoperable. The pulse duration is in the range from a few 100 ns to a few microseconds, the short-term peak power that can be achieved is up to a few gigawatts, depending on the type . It is used primarily in the military field and is used on guided missiles in combination with a vircator for electronic warfare in the field of electronic countermeasures (ECM).
The first flow compression generators (MK-1) and essential work on this were carried out in the Soviet Union in Sarov in the then object КБ-1 (today Russian Federal Nuclear Center / All-Russian Scientific Research Institute for Experimental Physics , РФЯЦ-ВНИИЭФ or RFJaZ-WNIIEF) in the early 1950s. developed around Andrei Dmitrievich Sakharov . Similar generators were later implemented at Los Alamos National Laboratory (LANL) in the USA.
Working principle
The functional principle of a pulse generator is based on the fact that a current-carrying conductor, designed as a closed conductor loop, for example in the form of a coil , initially causes a magnetic flux through the area A formed by the closed conductor loop . The magnetic energy stored in this magnetic field of the coil is due to the inductance of the conductor loop, which depends on the geometry and the area, and the electric current . If the conductor loop, and thus the area A , is reduced or compressed by an external force, there is an increase in energy in the coil, since work is carried out against the magnetic force. In a flux compression generator, this force is usually generated with the help of a detonation of conventional chemical explosives , but any other form of drive can also be used, so that a sufficiently rapid sequence of the process is guaranteed. The faster the compression process, the higher the achievable instantaneous performance. Due to the principle of destruction of the conductor arrangement, a flow compression generator can only be used once.
As an initial energy source, several capacitors are usually used , which are combined to form a capacitor battery and which initially ensure a current through the conductor loop when discharged. When the maximum current in the capacitors is reached, which is typically a few kA , the explosive charge is ignited, which leads to the "compression effect". The processes take place in very short periods of time, typically in the range of a few µs.
construction
There are several variants in the practical structure, in principle there are three different variants:
Hollow inner tube
The oldest design of the generator, called MK-1 by its inventor Sakharov, consists of a hollow inner tube. In this structure, in the center there is a hollow copper tube that is not electrically contacted inside and is slit in the longitudinal direction; the electrical coil embedded in explosives and the return line are located on the outside. The magnetic flux primarily spreads inside the pipe; during the detonation, the copper pipe is compressed and forms a rapidly narrowing short-circuit ring in which the compression of the metal pipe briefly results in a high magnetic flux density . With this design, the aim was to achieve high magnetic flux densities; electrical tapping of the instantaneous power is not provided for with this type of generator.
Helical flow compression generator
The Helical Flow Compression Generator or MK-2 is constructed similarly, but the explosives are inside the copper pipe. The coil is located on the outside, the copper pipe on the inside serves as the return conductor. The magnetic field spreads primarily between the surface of the copper pipe and the external coil. The explosive is ignited at one end of the tube, the detonation wave continuously pushes the copper tube outwards into the coil, which leads to a constant shortening of the coil length and thus to an increase in the field energy. At maximum power, a strong impulse can be delivered to an external load such as a pulse shaping network and a vircator . The maximum pulse current is up to 100 MA .
Disc-shaped flow compression generator
In this comparatively complex structure, there are several discs along an axis, which contain cavities in their structure. These cavities are lined with copper and the arrangement is filled with surrounding explosives. The explosives in the individual disks, each disk acting as an individual generator, are triggered one after the other by their own ignition devices. The total energy can be increased through the combination of several panes and the temporal overlap during ignition. The maximum pulse current with this arrangement is up to 250 MA .
Web links
- Electro-magnetic pulse (EMP) systems
- An Introduction to Explosive Magnetic Flux Compression Generators (PDF file; 2.20 MB)
Individual evidence
- ↑ LL Altgilbers, MDJ Brown, I. Grishnaev, BM Novac, IR Smith, Y. Tkach, I. Tkach: Magnetocumulative Generators (= Shock Wave and High Pressure Phenomena ). Springer-Verlag, 2000, ISBN 0-387-98786-X , doi : 10.1007 / 978-1-4612-1232-4 .
- ↑ a b c Lab-to-Lab, Scientific Collaborations Between Los Alamos and Arzamas-16. Retrieved March 18, 2015 .