Prompt nuclear EMP and Synchrotron radiation: a resolution of two approaches

The geomagnetic component of nuclear EMP generated by the prompt (t_max∼2 μs) γ-ray, neutron, and X-ray radiation from a nuclear explosion has been the subject of intense scrutiny for over 40 years. Recent work by certain members of the scientific community has suggested that a discrepancy exists in the calculations/derivation of nuclear EMP between treatments based on Maxwell´s equations and the high-frequency approximation and those derived from a summation over particles emitting synchrotron radiation. In principle, the two approaches should be identical simply because the well-known Lie´nard-Wiechert potentials for accelerating particles are derived from Maxwell´s equations. In this paper, we start from the Lie´nard-Wiechert potentials and derive an expression for nuclear EMP that is identical to previous work based on a solution of Maxwell´s equations. Thus, the putative discrepancy between the two approaches is resolved and Maxwell´s equations in this regard are again vindicated.