The Graphite Bomb: An Overview of Its Basic Military Applications

1979

c n c 1 RA0 r.Vj I. Technical epIt. , High Explosive Detonation and Tehnca Pedta Electromagnetic Interaction / C Sep-l 77Lpe.ne July-78 7. AUT .

Nucleation and Atmospheric Aerosols, 2002

Current theories of reaction processes suggest that changes in electronic band structure and radiation producing dipole oscillations occur during shock loading of an energetic crystal prior to detonation. To test these theories, a broadband antenna, capable of measuring polarization, was employed to observe shock-induced electromagnetic radiation from a crystalline explosive, RDX. The frequency spectra from these experiments were analyzed using time/frequency Fourier methods. Changes in conductivity resulting from this shock loading were also measured at the opposite end of the crystal from the shock source. A four-pointprobe arrangement was used to eliminate errors involving lead resistance. This arrangement uses two leads and a fast discharge circuit to pass current through the crystal interface at the time conductivity begins to change in conjunction with the arrival of the shock wave. Also reported are corresponding light (observed with a high-speed electronic camera) and submicrowave emission observed during the passing of the shock wave in the RDX crystal prior to detonation.

2012

HPEM is a catch-all acronym that includes many electromagnetic waveforms such as natural lightning, nuclear electromagnetic pulse (NEMP), high-power microwaves (HPM), moderate band signals and hyperband transients [1]. With the exception of natural lightning which has existed from time immemorial, the scientific discipline of HPEM started in the 1960s, when serious attention was paid to NEMP. Dr. Carl Baum played a key role in the evolution of HPEM [2]. In this paper, we will review some major milestones of this evolution and also attempt to look ahead.

IEEE Access

High-power microwave sources applied to a directed-energy weapon can lead to permanent damage by radiating concentrated energy in a specific direction to disturb or overload electronic equipment. The effect analysis on the target, such as electronics exposed to electromagnetic pulse, should be considered as an important factor in determining the performance of high-power microwave sources and conducting experimental evaluations. In this study, a magnetically insulated transmission line oscillator, one of the representative high-power microwave sources based on vacuum electronics device, was constructed and experimental analysis with respect to electromagnetic pulse effects was performed. The specification of the magnetically insulated transmission line oscillator used in this study corresponded to 3 GW of high-power electromagnetic wave pulses operating at L-band. The power efficiency was approximately 10-15%. For effective targeting, a Vlasov antenna that converts TM01 mode to TE11 mode was designed and fabricated. The radiation pattern was confirmed via fluorescent lamps, and to confirm the effect of the directed-energy weapon on the target, an effect analysis was performed using a portable electronic device as a sample. Furthermore, the electric field was measured with a D-dot probe and quantified and compared. This study presents a future blueprint of the value of the directed-energy weapon by predicting the radiant output power of the weapon in the far-field region after it is mounted on a movable ground vehicle or unmanned aerial vehicle. INDEX TERMS High power microwave (HPM), directed-energy weapon (DEW), electromagnetic pulse (EMP), magnetically insulated transmission line oscillator (MILO)

Reviews of Geophysics, 1974

Models of the processes whereby a nuclear detonation emits a coherent electromagnetic pulse fall into three classes: those involving Compton electron currents produced by interaction of prompt 3' radiation from the detonation with the environment, those involving photoelectron currents produced by the similar interaction of primary X radiation from the detonation, and those involving perturbation of the ambient magnetic field by the expanding plasma surrounding the detonation point. For each model considered the cause of the asymmetry in the current system necessary for the radiation of a signal is discussed. These causes include the earth-atmosphere interface, the atmospheric density gradient, anisotropy of the environment by virtue of the presence of the earth's magnetic field, nonuniform emission of the energetic radiation (3' and X rays) by the detonation, and asymmetries of the delivery vehicle and device case. The available experimental data are then examined in the light of the models. These data suffice to establish the models as probably being correct in their identification of the principal processes whereby the nuclear electromagnetic pulse is generated, but they are inadequate for a quantitative assessment of the accuracy of the models.

Directed energy weapons (DEW) comprise of systems that use one of the following electromagnetic energy devices namely, high power microwave/ radio frequency, lasers that provide a burst of photons, or particle beams. These weapons are very precise, adaptable, and flexible since both power and frequency of transmission can be varied. They however, face limitations due to power generation and heat dissipating capacity. All directed energy weapons operating in RF spectrum; from 100 MHz to 100 GHz, with corresponding wavelengths of 3m to 3mm; and which can generate power of ~100MW or more are classified as High Power Microwave (HPM) weapons. HPM scores over other DEW due to lower atmospheric attenuation and lesser propagation losses. The HPM weapons comprise of two main categories, namely the narrow band and the wide or the ultra wide band (UWB). Narrow band weapons generate a unique frequency centered on the nominal frequency of operation. For such weapons to be effective, the frequency of absorption of the target needs to be ascertained first. Wide band weapons overcome this deficiency by transmitting power across a wider range of frequencies. However, the power transmitted is less than that by narrow band weapons. Apart from the tracking, targeting and control systems, the main components of the HPM weapon system comprise1 of; a main power module which generates a low power electrical long pulse; a pulsed power system to convert low power output of the main power module in to high power short electrical pulses; a microwave source which utilizes the pulses from pulsed power system to convert them to electromagnetic waves; an optimizer system to distribute e.m. energy for transmission and coupling with the antenna; and lastly an antenna to direct the high power e.m. beam to the target. The HPM system depends upon the design of its radiating elements. If the system is not carefully designed its radiated energy can damage own equipment near the weapon. Critical aspects to be considered for effective radiation of the HPM pulse include2:-Directivity-the antenna design should be such that the HPM pulse does not radiate personnel and equipment in vicinity.-Efficiency-matching of radiating element and feed should be such that standing waves are not generated,-Power dissipation-design of HPM antennas are large to ensure that non-radiating energy is dissipated without causing breakdowns,-Dispersion-in applications where received signal processing is required dispersion of antenna must be taken in to consideration. The US Air Force Research Laboratory's (AFRL) Advanced Weapons and Survivability Directorate have categorized four major types of electronic effects3 that are experienced when HPM is directed towards a target. These are, Upset-which is a temporary disability/jamming of the electrical circuit/component, Lockup-temporary disablement which requires reset for restoration of normal functioning, Latch up – involves destruction of the node which is radiated by the HPM weapon, and Burnout-which results in melting of components / short circuiting. There are two ways by which HPM weapon energy can be transmitted inside the electronics of

2014

Generation of a high energy magnetic pulse with a flux compression generator requires first of all a good mathematical approach followed by simulations of the theoretical model in laboratory and in the field. The authors above have been members of a research team that developed an electromagnetic pulse device started by a conventional explosion. This paper describes the main steps in simulating and testing the compression of the magnetic flux needed to achieve the high energy magnetic pulse.

2011 XXXth URSI General Assembly and Scientific Symposium, 2011

In this work, we present a general methodology for modeling the coupling of electromagnetic fields with electroexplosive devices (EEDs). We discuss the assumptions and the necessary conditions to achieve the maximization of electromagnetic response of a canonical EED. The 2 E  product of the EED (E being the electric field and  the duration) is presented as a means for determining the electromagnetic environment that could lead to its activation from an external impinging electromagnetic field.

Scientific Bulletin of Naval Academy

Acta Physica Polonica A

In the study, electromagnetic weapon systems that are developed as an alternative to modern weapon systems are examined and a design for a rail type electromagnetic weapon system is intended. After a literature review on the sub ject, the comparison of electromagnetic and conventional weapons is made and models of electromagnetic weapons are elaborated. In the study, information of various electromagnetic weapons is provided but the focus is determined to be rail type electromagnetic weapons. Rail type electromagnetic weapons are examined in the study and the design of a low-power weapon prototype is made. For the model developed under laboratory conditions, 8 capacitors are used as a source of ignition. With the rail type electromagnetic weapon system designed, 2613.9 Joule energy is reached. The system components projected in theoretical calculations are enhanced throughout the application phase and are optimized for rail type weapon systems. For making theoretical studies and for drawing the graphs MATLAB software program is utilized. As a consequence, theoretical and empirical data is compared and commented, and some recommendations are formed.