EBW DETONATOR PDF
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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The Fat Man Model EBW detonators used an unusual, high reliability detonator system with two EBW “horns” attached to a single booster charge, which then fired each of the 32 explosive lens units. 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.
This is achieved via conventional explosives placed uniformly around the pit. Two EBW arms circled in light green. The slapper detonator is a more recent development along similar lines. 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.
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. Views Read Edit View history.
The larger round objects with two wires coming out parallel to the surface are diagnostic equipment.
When detnoator, it creates a strong electromagnetic pulsewhich is inductively coupled into one or more secondary coils connected to the bridge wires or slapper foils. This page was last edited on 31 Octoberat Conference SeriesVolumePart The resulting shock and heat initiate the high explosive.
Sign up for new issue notifications. The implosion must be highly symmetrical or the plutonium would simply be ejected at the low-pressure points.
EBWs were developed as a means of detonating multiple explosive charges simultaneously, mainly for use in plutonium-based nuclear weapons in which a plutonium core called a pit is compressed very rapidly. Closeup of a detonator set. Any further distribution of this work must maintain attribution to the author s and the title of the work, journal citation and DOI. An EBW has two main parts: The heating process typically takes milliseconds to tens of milliseconds to complete and initiate detonation in the primary explosive.
However, there is still not a universally accepted mechanism. Consequently, the detonators must have very precise timing. A low energy density capacitor equivalent to a compression generator would be roughly the size of a soda can. Conventional blasting caps use electricity to heat a bridge wire rather than vaporize it, and that heating then causes the primary explosive to detonate. EBWs use a different physical mechanism than blasting caps, using more electricity delivered much more rapidly, and explode in a much more precise timing after the electric current is applied, by the process of exploding wire method.
A very rough approximation for the capacitor is a rating of 5 kilovolts and 1 microfarad, and the peak current ranges between and amperes.
Exploding Bridgewire EBW Detonators are in widespread use and have proven reliability and performance characteristics. The extremely short rise times are usually achieved by discharging a low- inductancehigh-capacitance, detonatorr capacitor e.
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.
The heating rate is high enough that the liquid metal has no time to flow away, and heats further until it vaporizes. Their use ebbw limited by the thermal stability range of PETN. If the current rise rate is lower, the bridge may burn, perhaps causing deflagration of the PETN pellet, but it will not cause detonation. Modern exploding-bridgewire detonators arranged in a tray.
A view on the functioning mechanism of EBW detonators -part 1: electrical characterisation
This in turn has led to the calculation of the energy efficiency of the fireset bridgewire system and an estimate of the energy delivered post bridgewire burst. To find out more, see our Privacy and Cookies policy.
Detonators without such booster are called initial pressing detonators IP detonators. 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. However, they require a bulky power source for the current surges required.
This paper is the first of three characterising the initiation of PETN in an exploding bridgewire detonator to understand the underlying mechanism. Since explosives detonate at typically 7—8 kilometers per second, or 7—8 meters per millisecond, a 1 millisecond delay in detonation from one detonxtor of detonqtor nuclear weapon to the other would be longer than the time the detonation would take to cross the weapon. During initiation, the wire heats with the passing dbw until melting point is reached.
The flux compression generator is one alternative to capacitors. Buy this article in print. Detonator wires highlighted in yellow.
RP EBW Detonator
Booster charge circled in green. This is roughly 1, detomator 10, times longer and less precise than the EBW electrical vaporization. The EBW and the slapper detonator are the safest known types of detonators, as only a very high-current fast-rise pulse can successfully trigger them.
The results of the experimental work will be presented, together with the implications for the initiation mechanism of PETN in an exploding bridgewire detonator.