RP EBW Detonator. P/N . The RP explosive is contained in a ” thick stainless steel case which is crimped onto the plastic head. OPEN ACCESS. A view on the functioning mechanism of EBW detonators -part 1: electrical characterisation. To cite this article: E A Lee et al J. Phys.: Conf. Exploding Bridgewire (EBW) Detonators are in widespread use and have proven reliability and performance characteristics. Since their invention there have.
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Given a sufficiently high and well known amount of electric current and voltage, the timing of the bridgewire vaporization is both extremely short a few microseconds and extremely precise and predictable standard deviation of time to detonate as low as a few tens of nanoseconds.
Detonators Nuclear weapon design. Exploding Bridgewire EBW Detonators are in widespread use and have proven reliability and performance characteristics.
The most common commercial wire size is 0. Then an electric arc forms in the metal vapor, leading to drop of electrical resistance and sharp growth of the current, quick further heating of the ionized metal vapor, and formation of a shock wave.
RP EBW Detonator
The measurement of current, time to bridgewire burst and the transient voltage across the bridgewire at burst have enabled the determination of the energy used in bursting the bridgewire. An EBW has two main parts: Imprecise contact between the bridgewire and the primary explosive changes how quickly the explosive is heated up, and minor electrical variations in the wire or leads will change how quickly it heats up as well.
This page was last edited on 31 Octoberat The implosion must be highly symmetrical or the plutonium bew simply be ejected at the low-pressure points. This is sufficiently precise for very low tolerance applications sbw as nuclear weapon explosive lenses.
A view on the functioning mechanism of EBW detonators -part 1: electrical characterisation
Modern exploding-bridgewire detonators arranged in a tray. When fired, it creates a strong electromagnetic pulsewhich is inductively coupled into one or more secondary coils connected to the bridge wires or slapper foils. In the US, due to their common use in nuclear weapons, these devices are subject to the nuclear control authorities in every state, according to the Guidelines for the Export of Nuclear Material, Equipment and Technology.
A low energy density capacitor equivalent to a compression generator would be roughly the size of a soda can. E A Lee et al J. Since explosives detonate at typically 7—8 kilometers per second, or 7—8 meters per millisecond, a 1 millisecond delay in detonation from one side of a nuclear weapon to the other would be longer than the time the detonation would take to bew the weapon.
Closeup of a detonator set. This in turn has led to the calculation of detlnator energy efficiency of the fireset bridgewire system and an estimate of the energy delivered post bridgewire burst. During initiation, the wire heats with the passing current until melting point is reached.
From the available explosives, only PETN at low densities can be initiated by sufficiently low shock to make its use practical in commercial systems as a part of the EBW initiator. The EBW and the slapper detonator are the safest known types of detonators, as only a very high-current fast-rise pulse can successfully detoonator them.
Low- impedance capacitors and low-impedance coaxial cables are required to vetonator the necessary current rise rate. The precise timing of EBWs is achieved by the detonator using direct physical effects of the vaporized bridgewire to initiate detonation in the detonator’s booster charge.
Content from this work may be used under the detonafor of the Creative Commons Attribution 3. This is achieved via conventional explosives placed uniformly around the pit.
Conference SeriesVolumePart This has led to their common use in nuclear weapons. Consequently, the detonators must have very precise timing. However, they require a bulky power source for the current surges required.
The degonator detonator EBWalso known as exploding wire detonator is a type of detonator used to initiate the detonation reaction in explosive materialssimilar to a blasting cap because it is fired using an electric current. The larger round objects with setonator wires coming out parallel to the surface are detonaor equipment. The results of the experimental work will be presented, together with the implications for the initiation mechanism of PETN in an exploding bridgewire detonator.
The resulting shock and heat initiate the high explosive. To find out more, see our Privacy and Cookies policy. However, there is still not a universally accepted mechanism. The flux compression generator is one alternative to capacitors. A very rough approximation for the capacitor is a rating of 5 kilovolts and 1 microfarad, and the peak current ranges between and amperes.
EBWs have found uses outside nuclear weapons, such as the Titan IV safety conscious applications where stray electrical currents might detonate normal blasting caps, and applications requiring very precise timing for multiple point commercial blasting in mines or quarries. The EBW is the Y-shaped device with two wires coming in at angles along the surface.
Since their invention there have been numerous studies to identify the mechanism by which the exploding bridgewire initiates the explosive. Detonator wires highlighted in yellow.
This accounts for the heavy cables seen in photos of the Trinity ” Gadget “; high voltage cable requires good insulation and they had to detonatorr a large current with little voltage drop, lest the EBW not achieve the phase transition quickly enough. This is roughly 1, to 10, times longer and less precise than the EBW electrical vaporization. Booster charge circled in green. Their use is limited by the thermal stability range of PETN. In a fission bomb, the same or similar circuit is used for powering the neutron triggerthe initial source of fission neutrons.
The slapper detonator is a more recent development along similar lines.