VLF phase perturbations produced by the Soviet high-altitude nuclear explosion of November 1, 1962

Abstract

The Soviet high-altitude nuclear burst of 0912 UT on November 1, 1962, produced delayed perturbations of the VLF transmissions monitored at APL/JHU over five paths remote from the burst region. The burst-related VLF effects varied from 6 to 55% and averaged 32% of the normal diurnal variation. It is suggested that the VLF phase perturbations are produced by particles from the burst that drift to the remote regions and produce an ionization enhancement in the lower ionosphere in their first, and sometimes in their second, global orbit. The temporal histories of the VLF phase perturbations are compatible with a model wherein it is assumed that the trapped particles are electrons from the radio-active decay of neutrons, the artificial belt extending from an outer shell of L ≈ 3.4 to at least L = 1.9. Satellite particle data do not show an artificial belt of electrons from the decay of neutrons, a belt which in this case may have been obscured by the background flux of electrons from the natural Van Allen belt and from the artificial belts from the earlier Soviet explosions. Satellite data do, however, show a narrow belt of fission electrons ≳1 Mev with maximum flux at L ≈ 1.77 and a lower boundary at L = 1.73. These fission electrons did not affect the VLF paths intercepted by these shells. The VLF and satellite data agree that fission electrons ≳1 Mev were not present on shells above L ≈ 1.9.