Posts in category EMP-Tech

On the Validity of Certain Approximat...

On the Validity of Certain Approximations Used in the Modeling of Nuclear EMP

In legacy codes developed for the modeling of EMP, multiple scattering of Compton electrons has typically been modeled by the obliquity factor. A recent publication has examined this approximation in the context of the generated Compton current [W. A. Farmer and A. Friedman, IEEE Trans. Nucl. Sc. 62, 1695 (2015)]. Here, this previous analysis is […]

Empirical Formula of Effective Coupli...

Empirical Formula of Effective Coupling Length for Transmission Lines Illuminated by E1 HEMP

This paper presents empirical formulas of the effective coupling length (ECL) for the transmission lines illuminated by the horizontally or vertically polarized E1 HEMP, which is defined by the IEC standard. Based on the analysis and the numerical data of the ECL, the empirical formulas are developed through fitting first. Then, the empirical formulas are […]

Theoretical and Experimental Study of...

Theoretical and Experimental Study of Effective Coupling Length for Transmission Lines Illuminated by HEMP

This paper presents theoretical and experimental study of effective coupling length (ECL) for transmission lines illuminated by a high-altitude electromagnetic pulse (HEMP). Based on the transmission line theory, the ECL of transmission lines is analyzed theoretically and numerically first, then the ECL is applied to simply the analysis of nonuniform fields coupling with a power […]

Effect of Multiple Scattering on the ...

Effect of Multiple Scattering on the Compton Recoil Current Generated in an EMP, Revisited

Multiple scattering has historically been treated in EMP modeling through the obliquity factor. The validity of this approach is examined here. A simplified model problem, which correctly captures cyclotron motion, Doppler shifting due to the electron motion, and multiple scattering is first considered. The simplified problem is solved three ways: the obliquity factor, Monte-Carlo, and […]

Parametric Study of HEMP-Thruster Dow...

Parametric Study of HEMP-Thruster Downscaling to {mu } N Thrust Levels

Many on-going European Space Agency (ESA) science and earth observation missions are based on precision attitude control and formation flying. All these missions impose strong requirements on propulsion system which should provide low thrust, low noise, and high-precision thrust vectors in up to 16 directions. Also as most of these missions have a platform with […]

Analysis of Shielding Effectiveness o...

Analysis of Shielding Effectiveness of Reinforced Concrete Against High-Altitude Electromagnetic Pulse

This paper is focused on the analysis of the shielding properties of reinforced concrete under impinging high-altitude electromagnetic pulse. The reinforced concrete provides frequency-dependent shielding effectiveness mainly due to the embedded metallic grid rebars. For characterization of the concrete, three different configurations, i.e., concrete, rebar, and combined reinforced concrete, are analyzed in detail. In addition, […]

Back to Results Shape Properties of P...

Back to Results Shape Properties of Pulses Described by Double Exponential Function and Its Modified Forms

Double exponential function and its modified forms are widely used in high-power electromagnetics such as high-altitude electromagnetic pulse and ultrawide-band pulse study. Physical parameters of the pulse, typically the rise time tr, full width at half maximum tw, and/or fall time tf , usually need to be transformed into mathematical characteristic parameters of the functions, […]

Early-time high-altitude electromagne...

Early-time high-altitude electromagnetic pulse environment (E1) simulation with a bicone-cage antenna

The simulation of the early-time High-altitude Electromagnetic Pulse (HEMP) environment (E1) with bicone-cage antenna in free space requires utilization of the spherical wave to reproduce the boundless plane wave. The transient radiation of the antenna above the lossy ground is computed using the Finite-Difference Time-Domain (FDTD) method. The determining factors of the field waveform are […]

Progress in High-Altitude Electromagn...

Progress in High-Altitude Electromagnetic Pulse (HEMP) Standardization

Since the publication of the last IEEE Transactions on Electromagnetic Compatibility special issue on nuclear electromagnetic pulse in 1978, significant progress has been made in the development of high-altitude electromagnetic pulse (HEMP) standards. The standards cover HEMP environment definition, protection requirements, and test methods. In particular, civilian standards have been developed in recent times as […]

Introduction to the Special Issue on ...

Introduction to the Special Issue on High-Altitude Electromagnetic Pulse (HEMP)

This paper introduces the papers included in the Special Issue on high-altitude electromagnetic pulse. Published in: IEEE Transactions on Electromagnetic Compatibility  (Volume:55 ,  Issue: 3 ) Page(s): 410 – 411 ISSN : 0018-9375 DOI: 10.1109/TEMC.2013.2265044 Date of Publication : June 2013 Date of Current Version : 11 June 2013 Issue Date : June 2013 Sponsored […]