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Deep-hole blasting and chamber blasting technology are widely used in mining and large-scale earth-rock excavation or landfill projects, due to their advantages of high efficiency and low cost. However, their use is often accompanied by misfire accidents, and generally misfire is relatively hidden, as well as difficult to quickly detect and identify, making misfire the greatest potential safety hazard in blasting construction. This paper presents a method and system of frequency division multiple access (FDMA) detection and recognition for blasting misfire, based on electromagnetic wave propagation theory and radio frequency identification technology. Next, the feasibility of frequency division multiple access (FDMA) misfire detection method is analyzed by means of theoretical deduction. Combining field and laboratory tests, it is concluded that the existence of underground misfire with a linear distance of 225 m can be detected. In addition, the detection frequency range is 975-5025 Hz, and the recognition accuracy of multi-frequency signal can reach 2 Hz. The stability of the electric detonator in an electromagnetic environment is discussed, and the danger criterion of the electric detonator in the electromagnetic environment is obtained. When the power of the signal transmitter is less than 120 W and the induction area of the electric detonation network is less than 0.5 m2, then the electric detonator is safe. The misfire detection and recognition system has been successfully applied in a deep-hole blasting of an open-pit quarry. It is observed that when the distance between millisecond blasting holes is equal to greater than 5 m, the detection signals between holes will not interfere with each other. This paper provides a reliable, systematic and complete research method for remote wireless detection and identification of misfire, and also provides a basis for the safety of blasting construction and misfire detection in related projects.

Pyro-breaker is a fast-responding and high-reliable explosive-driven circuit breaker, which has been applied in several quench protection systems, such as ITER and Experimental Advanced Superconducting Tokamak (EAST). The choice of the detonator and the dosage of the explosive is a significant part of the development of a new pyro-breaker. The presented pyro-breaker has two units, both driven by explosives, but the specific driving structures are different from each other. The numerical modeling of these two units includes the coupling of multiple materials, and the model is complex due to the cooperative action of each other. The numerical models of the explosion on the conductors are built respectively for the two units, and the simulation is carried out in ANSYS / LS-DYNA. The conductor structure, explosive dosage, and driving mechanism are checked and calculated. Based on the results of numerical simulation, several explosion tests were conducted to verify the accuracy of the model. The breaking processes of the conductors under different dosages and shaped explosives were analyzed. The mechanical structure of the conductor was optimized and the forming problem after the explosion was solved. The model will be the theoretical basis for the designing of the pyro-breaker in the quench protection system of China Fusion Engineering Experimental Reactor (CFETR).

The MEMS detonated device is the new generation of pyrotechnics, the safety of which influence the whole munition system, so the device is only controlled by single electro signal is unreliable. In order to solve the difficulties, a MEMS detonated device with built-in safety and arming device is proposed in this paper. The device is composed of the detonator, the safety and arming device (SAD), the cover plate and the PCB. The detonator is a NiCr alloy bridge foil with Al/CuO energetic composite film. The SAD is set on the top of the detonator to add a mechanical insurance. With 11V driven voltages of electro-thermal actuators, the SAD can realize the bidirectional large-displacement movement of the barrier, which can reciprocally switch the device condition between safety condition and arming condition. The SAD has a Silicon/Ni enhanced barrier. In safety condition, it can block the flame which the detonator under 64V voltage stimulating generate. And the flame can go through barrier in arming condition.

The most effective resonant mode of industrial explosives ignition by high frequency current was examined. Specifications of electric firing circuit at resonance occurrence in general and special cases were analyzed and defined. Conditions of self-compensation of electric firing circuit reactive parameters were defined. T-circuit equivalent of real electrical firing circuit was developed. Current impulse at resonance was defined. Grapho-analytical method to define refusals or electric detonator operation in the circuit depending on received current impulse was developed. By theory and by experiment were defined reactive elements values, brought into the electric firing circuit in order to achieve resonant mode, also electrical firing circuit general operation mode and in case of resonance and reliability conditions were analyzed. Recommendations for increasing of blasting devices efficiency at electric circuit ignition was provided.

In this paper, we propose a new trend to function a responsive radio jamming device that discovering the signals of one or a group of the terroristic radio-controlled improvised explosive radio devices, processing and relaying them so that the remote-controlled detonator of the explosive installed at the object cannot be triggered. The distinctive feature of our approach is related to the processing of received radio signals, when instead of the operation of introducing noise interference into each radio channel exclusively used in existing multi-channel jammers, a common single-channel optoelectronic processor is exploited, which generates many replicas of received radio signal that critically degrade its quality.

In order to study mechanical overload characteristics semiconductor bridge detonators under the penetration environment of the multi-layer steel target, the simulation model of the penetration process of the multi-layer steel target in different states was established by use of LSDYNA. The relationship between the length of the shell, the diameter of the shell, the length of the column and the target plate arrangement order, the target plate spacing, the penetration angle were investigated. The results show that When the thick target is in the middle of two thin targets, the axial load of the detonator is small; when the target spacing is 0∼1 times projectile body, with the target spacing increases the axial load of detonator increases; When the penetration angle is between 0° and 20°, as the angle of penetration increasing the detonator is less overloaded.

In this paper we present our work on the use of LoRa as a network technology for detonation of low explosives in underground mining. Using explosives underground is a potentially hazardous activity that mining companies are keen to make safer by removing personnel from near the site of the detonation. Currently detonation is commonly carried out using lengths of copper cable or infrared transmission, both of which limit the distance between the initiator and the explosives. The wireless technology LoRa, is an attractive alternative. LoRa has a much longer transmission range than infrared transmission and other wireless technologies such as WiFi and ZigBee. We have developed and trialed in a working underground mine a prototype system for carrying out such detonations. The system makes use of LoRa as a multi-hop message passing system from an Initiator to a Detonator via a number of Relays. We describe the messages that are passed through the network. We also describe how we deal with contention, broadcast storms and duplicate messages. Our approach is robust, easy to deploy and gives deterministic delay. We also present measurements of signal strength taken underground. Our results indicate that underground LoRa wireless transmission suffers severe fading without line of sight but where this is a line of sight underground, we show that LoRa propagates considerable distances.

The article discusses a system for testing fiberoptic lines for pyroautomatic systems. An optical fiber is proposed to use to deliver the control signal to the optical detonator or to the automaton in such systems. The integrity of the optical line is checked by measuring back reflections. The basis of the developed device is an optical fiber, working as a dielectric, that eliminates the possibility of electrical interference or static. The prototype of the system was assembled from the following components: multimode fiber splitters, a delivery optical fiber and an input unit with a dielectric mirror sprayed at the end. The recipe and the model of a reflective dielectric coating are given. The power laser diode was tested in critical temperature conditions. The results of checking the integrity of the fiber-optic circuit are presented. Such a system can be used in the mining industry for initiating explosives by laser radiation.

The exploration and mining of minerals on extraterrestrial bodies in the solar system: planets, moons, planetoids, asteroids and comets requires the development of fundamentally new primary explosives that are not subject to spontaneous detonation during vibration and static discharges when launched from the ground. Available detonators do not fully meet these requirements and pose a danger to future space missions, therefore, are considered undesirable as payload on board. Therefore, the synthesis, research and testing of new energetic materials sensitive exclusively to the selected wavelength, duration and energy of the exciting laser pulses is of particular relevance.

In the process of initiating detonation of explosive materials, the environmental parameters have serious nonlinear effects. Aiming at the problem of the variation, uncertainty and nonlinearity of component parameters which can not be solved by linear function, The Volterra series model is combined with the gene expression programming, The algorithm uses the Volterra series to accurately reflect the characteristics of the nonlinear system to describe the initiation process of the detonator, so that no matter how the environmental parameters change, The intrinsic characteristics of initiating explosive are not changed, and the GEP algorithm overcomes the shortcomings of traditional identification methods and identifies the correct model. The simulation results show that this method can accurately and quickly identify the initiation process.

In this paper we analyze the universal mathematical model of the electric firing circuit representing its constituent parts in the form of quadrupoles connected to each other. By means of this model we analyze the state of the electric firing circuit effected by the four most frequently encountered factors: direct current, alternating current, exponential effect, generalized effect. We have calculated the transmission coefficients for current and voltage for this circuit based on which we have determined the dependence for current distribution between the electric detonators in the circuit and the probabilities of their activation. The maximum possible number of simultaneously initiated electric detonators is determined. A numerical example of calculation is given. Practical recommendations on the design of blasting devices, on the optimal electromagnetic compatibility of the electric firing circuit, as well as on increasing the safety and reliability of blasting operations are given.

To solve the problem of detecting for Missile Initiating Devices (MID) before launching, an intelligent equivalent equipment based on Field Programmable Gate Array (FPGA) is designed and realized. The system adopts microchip EP3C16F256C8 and its peripheral circuit to equal to the electric detonator resistor while passage-testing. It also can be used to detect the sequence of electric information while signal testing. Through passage-testing, experiment of current timing and voltage timing shows that the electric detonator resistor value and the sequence width can meet the design requirement. The testing is investigated on the experimental platform. Also, the system has the advantages of high reliability, good maintenance and strong practicality. It can be widely promoted and applied.

In this work we analyze the electric processes in the electric firing circuit. A model of electric firing circuit is developed and analyzed with due regard to the impact of various internal and external energy sources. A mathematical model of the electric firing circuit in the form of a matrix equation reflectIIITII its electric state under the simultaneous operation of both standard and external sources of energy is developed; a semigraphical method for calculation of electrical detonators reliability is proposed. The complex analysis electroexplosive chain algorithm takes into account the possible impact of stray currents and their influence on the security (the possibility of a premature explosion) and reliability (possible occurrence of failures at initiation) of electroexplosion work. Application of the proposed method and algorithm is illustrated in the equivalent circuit representing the most typical electroexplosive chain option. The article describes application of the proposed mathematical model of the electroexplosive matrix circuit, the developed algorithm and method illustrated in the equivalent circuit analysis which represents the electroexplosive chain most typical option.

This paper presents a measurement system for testing of electric detonator’s firing pulse. The measurement system consists of a developed current source that is controlled by a virtual instrument (VI) and the second VI measures true delivered pulse to the detonator. The system was tested using dummy detonator resistances to determine the system properties and limitations and it was concluded that this solution complies with the requirements of the standard, it is cost effective and has good repeatability.

Detonator plays a critical role in ignition chain of aerospace vehicle. As it is a single shot device initiating ignition chain, it has to cater two contrary requirements i.e it should be Safe against unintended initiation and reliably function upon receipt of intended command. Detonators being single shot devices, the full functional testing is not feasible as it calls for consumption of device itself by test firing. Thus in addition to measurement of few electrical parameters & non-destructive tests (NDT), reliability of the lot is mainly assessed from performance of few randomly selected detonators test firing from that batch. This paper deals with the category of detonator that is initiated with electrical current pulse and thermal response testing of such detonators using the developed thermal response tester. Tester helps in revealing poor thermal contact of electrical bridge wire with initiating explosive and imperfections in bridge wire and soldering. Tester isolates the defective detonators and gives insight in to type of defects which can be used for taking corrective measures in future.

In recent times, landmines have created unaccounted fatalities across the world. The detection of mines buried beneath the surface is paramount to avert inhuman risks associated with mine deployment and explosion. In this paper, a substantive design of an intelligible landmine detective system is proposed based on precise control over aerial motion planning and metal detection. The proposed mine detector is capable of providing virtual mapping of the traversed area and a concatenated map of the points of metal signatures, no matter whether it is a rough terrain or inclined surface. Since the aerial route is considered for surface exploration, the avoidance of assimilating the mine paths is reliably possible. The dynamism of path generation correlates to GPS coordinates of detected mines. A modified metal detection technique is developed based on electromagnetic radiation estimates to discriminate metals, mines and bare explosives like RDX. The proposed system can identify the explosion type of the detonator and recognize electrically controlled explosives. This paper appends several test studies of the system under different consequences, such as different location of metals, variation of metals in size and type, varied experimental arena and the evaluated results affirm the reliability and cost-effectiveness of the reported framework.

Los Alamos “Ranchero” Magnetic Flux Compression Generators (FCGs) have been used to power imploding liner loads. The fundamental FCG design is based on a cylindrical detonation system that expands the armature simultaneously into a coaxial generator volume and has been shown to generate currents as high as 76 MA. Analysis of the 76 MA test results revealed a weakness in the design at the output glide plane. To prevent premature shorting at the output current slot of the generator, the armature/glide plane interface was originally designed to lag the leading edge of the armature. However, 2D-MHD calculations reveal that at very high currents a magnetically driven aneurism develops in this lagging section which reduces the performance of the generator. A new model Ranchero is being developed to correct this weakness and provide enhanced performance. In the new model, the output glide plane is eliminated and the armature is extended along the FCG axis, with its radius increasing along a curve until it reaches the current output slot. A cylindrical detonation system of the type required for earlier designs continues to be used, and the high explosive (HE) in the extended section is detonated by the last point of the cylindrical detonator. The stator of the FCG is contoured, allowing the contact point of the armature to zipper from the input to the output end in the last few μs of flux compression. In addition, the new model Ranchero is intended to use PBX 9501 (9501) for the HE and also remove the smoothing layer, which has been part of all Ranchero HE systems to date. Both of these factors lead to increased performance. 9501 is more energetic than the PBXN 110 used in Ranchero generators to date, and both calculations and experiments have shown that the smoothing layer is not needed when the detonator point spacing is 18 mm. Tests of original model Rancheros using PBXN 110 castable HE, with an imbedded smoothing layer, demonstrated an armature expansion velocity of 3.1 mm/μs. Further tests show that removal of the smoothing layer increases the speed to 3.3 mm/μs, and replacement of the cast PBXN 110 with 9501 without a smoother gives a velocity of 3.8 mm/μs. Designs, concerns, and experimental results facilitating the new model Ranchero are presented. In addition, performance estimates are given for the initial imploding liner tests to be conducted, and further computational details are presented in a companion paper given by C. L. Rousculp and others at this conference.

The following paper researches into application of digital technology for explosives performance test, especially ballistic mortar test. The proposed approach provides a direct measurement of maximum throw angle of pendulum in ballistic mortar test. The measurement equipment for ballistic mortar (MEBM) is designed, produced, and applied in the defense industries in Vietnam. MEBM is developed and produced based on angle encoder, CPU S7 200, TD 200. With the new proposed approach, the measurement process, signal transfer, digital signal processing, data computing, and display are fully automatic. It overcomes the disadvantages of old approach, such as indirect measurement of throw angle, where measurement error depending on marker record, rule, and subjectivity of measurer. The testing and triggering detonator is integrated in MEBM.

Ferroelectric Generators (FEGs) are compact explosive driven high voltage generators. They consist of a small explosive charge, ferroelectric ceramic, and output circuit. There has been and continues to be very active Small Business Innovative Research (SBIR) programs to develop FEGs as very compact power supplies for a variety of loads including antennas, neutron generators, and detonator arrays. In this paper, we will report on some of our recent efforts to improve the performance of FEGs and their components.

Ferroelectric Generators (FEGs) are compact explosive driven high voltage generators. They consist of a small explosive charge, ferroelectric ceramic, and output circuit. There has been and continues to be very active Small Business Innovative Research (SBIR) programs to develop FEGs as very compact power supplies for a variety of loads including antennas, neutron generators, and detonator arrays. In this paper, we will report on some of our recent efforts to improve the performance of FEGs and their components. In addition, we will look at what impact the load (resistive, capacitive, and inductive) has on FEG operation. We will also examine several specific loads that have been powered by FEGs.

Improvised explosive devices (IEDs) pose a significant hazard to allied forces. Effective countermeasures should exploit components that are commonly found in IEDs. This paper presents the computer modeling and measurement of the monostatic radar cross section (RCS) of one of these components, the electric hot-wire detonator. Results indicate that the common mode associated with the detonator's casing and lead wires provides the largest RCS contribution, ranging between -22 and -16 dBsm in the 3-10 GHz frequency range. Although a differential mode can be excited between the lead wires, its contribution to the monostatic RCS is negligible. The effectiveness of twisting the lead wires to reduce the RCS is also investigated.

This paper describes the successful experience of the directional control blasting demolition of 210m reinforced concrete chimney, and elucidates the determination of the project scheme, parameter design, electronic digital detonator detonating network and blasting safety technology. Based on the characteristics of the large-size chimney, dense reinforced bars and high strength concrete structure, pre-cut the large-size oriented window to reduce the blasting area and destroy the chimney's ring beam structure. Especially, based on the characteristics of the over-high chimney with heavy deadweight, this paper provides the comprehensive protection method for anti-fly rock splash, vibration reduction and dust fall. By observation from the multiple points of view, the comprehensive vibration reduction protection method can effectively control the secondary disaster resulted from blasting.

A high-power, high-energy pulsed-power generator, based on a 415 kJ / 22 kV capacitor bank, has recently been developed and tested indoor at Loughborough University. The generator can drive a high-impedance system, generating a total electrical power of many GW while depositing Joule energy of many tens of kJ. The arrangement is based on inductive storage technique that includes a 600 kV high voltage transformer, two closing switches and an opening switch. The high-Coulomb closing switch in the primary circuit is activated using detonators while the closing switch, mounted in the secondary circuit to condition the load output, uses a high-pressure gas self-breakdown closing switch. The opening switch in the primary circuit is an exploding wire array made from thick copper wires fired in quartz sand. Recently the entire system, including its command and control unit, was mounted into two ISO containers powered by diesel generators. The paper will describe the resulting mobile system and provide details of its performance capabilities.

Commercially available Electro-Explosive Devices (EEDs), such as blasting caps, use electrical current to initiate a primary charge. Various detonators including bridge wire, match-type, exploding bridge wire, and slapper. The basic operating principle of the match-type device is to heat the ignition element to the ignition temperature of the primary explosive. The normal operation current profiles, both constant current and pulsed excitation, are well known, as is the ignition temperature. However, as safety and reliability are of great concern, both in the operation and storage of EEDs, the susceptibility of these devices to transient or spurious fields is of interest. The susceptibility of match-type EEDs to high pulsed electric fields is examined. A Finite Element Method (FEM) simulation is performed using COMSOL to determine the induced current in the bridgewire due to applied electric fields and the resulting Joule heating of the wire. Several situations are investigated including the EED in conductive and non-conductive media and leads open or terminated representing operational and storage conditions.

Electric hotwire detonators are commonly used in the construction of improvised explosive devices. This paper explores the electromagnetic susceptibility of a commercial detonator when it is exposed to continuous wave, linearly-polarized plane wave radiation. The aim is to assess the feasibility of inducing sufficient current in the detonator to cause its explosion. For selected lead wire configurations, analytical formulae are used to predict the resonant frequencies of the detonators. Computer modeling is then used to simulate the induced current on the detonator's bridge wire during electromagnetic illumination. The predictions are compared with experimental measurements of induced current on commercial detonators.

Choosing reasonable wind speed is the key to the design of dust removal system. Aiming at the problem about the gunpowder held up in the dust pipeline of dust removal process in the detonator auto-assembly line, on the basis of the theory of gas-solid two-phase flows, this article analyses and studies this problem and points out the leading influence factor, thus offers the theoretical foundation of choosing reasonable wind speed in the dust pipe network.

Consistency of ignition sensitivity of electric-detonator is the key to series simultaneous blasting in engineering. To tackle the problem of inaccurate measurement of sensitivity, basd on the electro–thermal response principle, a work of analyzing the characteristic parameters obtained by the nondestructive testing technique was carried on, a mathod was found to set up the fuzzy pattern of product’s sensitivity. The electric-detonator can be classified in terms of sensitivity through this fuzzy pattern identification method. Experiments had shown that the reliability of series simultaneous blasting of electric-detonator of the same sensitivity was raised significantly.

Several previous studies have shown that threat detection performance of X-ray operators can be increased substantially if computer-based training (CBT) is used. This applies particularly to objects that are never or rarely encountered at a security checkpoint as for example Improvised Explosive Devices (IEDs). However, little is known so far about the importance of using different types of IEDs in CBT such as conventional, unconventional and inert IEDs. Conventional IEDs are made with real explosive and conventional detonators with a primary and secondary charge. Unconventional IEDs are made with real explosive and unconventional detonators that do not contain a primary charge. Inert IEDs are made with explosive stimulants and fake detonators.

An effort is underway to determine the electromagnetic (EM) characteristics of hot-wire detonators to quantify the possible effects of EM radiation. The analyses include a comprehensive investigation of physical detonator characteristics, which is then used to model detonators using EM theory and numerical simulations. The theoretical analysis treats the detonator as a cascaded transmission line incorporating several different dielectric regions, and examines both differential and common mode excitation. In addition, the detonator is modeled and simulated using ICEPIC (Improved Concurrent electromagnetic particle in cell), a finite-difference-time-domain (FDTD) EM solver. The cascaded transmission line model is then augmented with additional circuit elements whose values are found using ICEPIC. This combination produces a refined transmission line model that is implemented in MATLAB and can be run quickly for a wide range of detonators to determine possible deviations in radio frequency (RF) response due to manufacturing variations. A detailed RF response is not a given specification for detonators and, therefore, it is not a characteristic that is controlled during manufacturing. The results of both the analytic and computational methods, including detonator input impedance and resonant frequencies, are compared.

The received power level in the bridgewire of the military ammunition in the close proximity of a mobile RFID reader is analyzed. The electric detonator is modelled as a receiving antenna and its gain, directivity and input impedance are evaluated using a commercial electromagnetic simulation software. The near-field coupling between a half-wave dipole antenna and the 105/120-mm tank ammunition detonator is measured and compared with the theoretical prediction at 900 MHz. Based on the measurement and theory, the safety of the 900 MHz passive RFID system for defense ammunition management is discussed.

Experiments were conducted to investigate the use of thin radially spoked metallic foils as fast-acting opening switches operating on nanosecond timescales. Such devices could be useful in special applications requiring a tailored output from a pulsed power source. The advantage of this concept is that the device is inexpensive, simple, rugged, and reliable for single shot applications. Experimental results are presented and discussed. The effects of varying several fuse parameters are summarized and some limitations of the design are discussed.

In this work, we present the development of a handheld analyzer for actuation and sensing control of a disposable biochip for point-of-care monitoring of clinically relevant parameters. The disposable biochip has integrated on-chip air bursting detonators for fluid driving linked to a smart passive microfluidic system and an array of biosensors capable of simultaneously monitoring oxygen, glucose and lactate concentrations in human blood. The handheld analyzer houses the SMT (surface mount technology) based electronics system for providing the driving signals to the air bursting detonators and to monitor the analyte signals from the biosensors. We have designed, tested and characterized the analyzer using the disposable biochips to test analytes from human blood. The analyzer developed in this work is /spl sim/ 5.25" /spl times/ 3.5" times; 1.5" and is currently the smallest unit capable of multi-parameter detection from human blood samples.

Due to changes in production requirements the current facility was no longer adequate. A simulation study was conducted to help quantify the impacts of additional capacity, when that capacity should be brought online, and how to manage production in the interim before the new facility is available.

A new concept of a disposable air-bursting detonator as an alternative on-chip power source has been proposed, designed, and successfully demonstrated for disposable lab-on-a-chips or biochips. In this new detonator, a microheater is positioned on the thermoplastic membrane attached over a pressurized chamber. By applying an electrical pulse into the microheater, the thermoplastic membrane can be broken and then the pressurized air will be detonated to drive liquid samples through microchannels. Both air pressure and detonating temperature are adjustable to obtain the desired driving pressure response. Dynamic pressure response of the fabricated air-bursting detonator has been simulated and experimentally characterized. Due to its compact structure and fast response, this detonator will be a promising alternative power source to drive fluid samples in disposable lab-on-a-chips or portable clinical diagnostic kits.

Safety units in cars such as airbags or seat belt pretensioners protecting passengers of cars against risks of injury in the case of an accident are equipped with detonators. They are typically activated by electro-explosive devices where resistive wire elements are generally considered as well established initiator systems. Crash sensors in cars induce, in the case of an accident, a current pulse in this resistive initiator element. As the device is heated up to a critical temperature the explosive detonates and consequently the airbag or the retention system will be released. Thick film technology has been evaluated for the realisation of appropriate resistive ignition elements as an alternative to the conventional wire elements, which are considered to be capable of meeting future requirements of the automotive industry. The performance of thick film initiator elements is evaluated on the base of numerical simulation utilizing finite element method.

Two slapper detonators constructed of silicon with conventional microelectronic fabrication techniques were demonstrated. In both devices, a barrel was formed by preferentially etching a cavity in the substrate. The conductive bow-tie of the slapper was fabricated by two different techniques. The first technique involved selectively depositing metal at the base of the cavity (i.e., metal bow-tie structure). The second approach involved the selective diffusion of impurities into the base of the cavity to greatly increase the conductivity of the silicon (i.e., diffused bow-tie structure). It is demonstrated that both devices operated as intended. The diffused bow-tie device exhibited an interesting effect due to the negative thermal coefficient of the resistivity of the silicon. The effect may be exploited to improve the EMI (electromagnetic interference) and ESD (electrostatic discharge) insensitivity of the device. >

This paper describes a water shock tube for dynamic calibration of high pressure transducers up to 1000 MPa. The apparatus has an inner diameter of 30 mm and a length of 550 mm. The lead azide detonator is used as an explosive source. The pressure waves is monitored by a dispersive pressure bar gauge made by PVF2 piezoelectric film. Two different kinds of high pressure transducers have been tested by this apparatus, and their dynamic responses characteristics are obtained. >

A mathematical model of detonators which describes the resistance of the exploding bridgewire or exploding foil initiator as a function of energy deposition will be described. This model includes many parameters that can be adjusted to obtain a close fit to experimental data. This has been demonstrated using recent experimental data taken within Sandia National Laboratories.

During the development of a high-efficiency single-turn electromagnetic launcher, it became apparent that the main limiting feature was the closing switch used to connect the launcher coil to the charged capacitor forming the initial energy source. Both experimental and theoretical considerations established that, even by the time the projectile attained the terminal velocity, more than 30% of the initial capacitor energy had been absorbed in the simple and low cost nail switch that was being used. In an attempt to maximise the launcher efficiency, the characteristics of five different switch technologies were investigated. The initial capacitor voltage could be up to 30 kV and the launcher coil current peaked at up to 900 kA in about 1 /spl mu/s, and in addition to the nail switch, those considered were triggered spark gaps, nail switches, surface switches, metal-to-metal detonator switches and solid dielectric switches.

Summary form only given. Phillips Laboratory has developed a fast closing shutter designed to protect diagnostics or other devices from damage due to plasma and solid debris subsequent to exposure to high energy transient events such as PL's solid liner working fluid compression geometry. The device uses a cartridge brass (alloy C26000) tube with a 0.8 cm diameter biconic orifice which is crimped shut in 15 /spl mu/s after a 60 /spl mu/s delay. The crimping is accomplished by the simultaneous impact of two opposing 3 g Titanium slugs each propelled by a Reynolds, Inc. RPI Electronic Bridge Wire detonator. The crimp forms a high vacuum seal with a leak rate with an established upper bound of 10/sup -9/ l/s STP air. The assembly is contained by a reusable 14 cm by 14 cm by 5 cm heat treated chrome molybdenum steel casing. The only expendables are the tube, the RP1's, and two 2 g steel disks which buffer the Ti slugs from the RP1's with a total cost of about $400.

The goal of the Los Alamos Foil Implosion project (Trail-master) is the development of an intense source of soft x-rays for materials and fusion studies. The x-ray source in the Trailmaster project is a foil initiated z-pinch. The next system in the Trailmaster project is designed to deliver 15 MA of current to the imploding linear creating approximately 1 MJ of soft x-ray radiation in a submicrosecond pulse. This system, designated Procyon, will consist of a Mark 9 helical explosive generator, an explosively formed fuse (EFF) opening switch, detonator closing switches, a vacuum powerflow channel, a plasma flow switch (PFS), and the imploding foil load. In the present paper we will focus on the computational modeling of the overall Procyon system. This effort includes circuit and zero-dimensional point mass (slug) modeling, 1-D and 2-D radiation MHD calculations and 3-D radiation transport and view factor modeling of the vacuum powerflow channel. 7 refs., 10 figs.

The Los Alamos National Laboratory has applied the explosive magnetic flux compression generator (FCG) technology to the high-energy foil-implosion project, Trailmaster, to reach energy levels unattainable by other methods under current budget constraints. A required component for FCG systems is a power-conditioning stage that matches the slow risetime of the energy source with the fast-risetime requirements of the foil-implosion load. Currently, the Trailmaster concept is based on a two-step process of combining an intermediate power compression stage with a plasma flow switch (PFS) that will deliver energy to an imploding foil on the order of 100 ns. The intermediate power compression stage, which is the main emphasis of this report, consists of an energy storage inductor loaded by the FCG (the energy sauce) and an associated opening and closing switch. In our Procyon testing series, a subtask of the Trailmaster project, we have explored two approaches for opening and closing switches. One uses an explosive opening switch (EFF) and a detonator-initiated closing switch, the topic of another paper at this conference, and the other a resistive fuse opening switch a surface tracking closing switch (STS), the subject of this presentation. This latter concept was successfully tested last summer with amore » complete plasma flow switch assembly except the dynamic implosion foil was replaced by a rigid passive inductive load. We present data on the performance of the fuse opening switch, the surface tracking closing switch, and the plasma flow switch. 7 refs., 9 figs.« less