An Investigation Into the Quasi-Static Phase of the Surface Burst Source Region EMP (Electromagnetic Pulse).
Abstract
A numerical solution was developed to find the aboveground late-time magnetic fields resulting from a surface nuclear burst. The time derivative in Maxwell's magnetic curl equation was ignored and the result was expressed in integral form using Stokes' law. This expression is expanded in spherical coordinates, the radical Compton current and the radical conduction current source terms were calculated, using the time-independent code, and the polar integrals were calculated. Magnetic field values were calculated and compared with analytic expression. For r < 2 Km, the results differed by less than 2.7. However, for r > 2 Km, the numerical values were an order of magnitude larger. The electric and magnetic field calculations were then used to test the spatial and temporal regions of validity of the simplified boundary condition and the quasi-static approximations. The assumption that the ground conductivity greatly exceeds the air conductivity leads to a simplified boundary condition at the earth's surface (E sub r = 0), and, in turn, to an inner radial limit to the validity of the results. The quasi-static approximation that the electric fields be derivable from a scalar potential determines the time regime over which the results are valid. The computer program included in this report is useful for late-time EMP calculations because of the short execution time and its wide range of applicability.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1984
- Accession Number
- ADA144598
Entities
People
- K. M. Hodgdon
Organizations
- Air Force Institute of Technology