Nuclear explosion phenomena and their bearing on radio detection of the explosions

The characteristics of nuclear explosions are first discussed. It is shown that nuclear events can create radio noise signals, change the height distribution of existing ionospheric ionization, and produce fresh ionization; the last effect is the most important in radio detection. The influence of X-rays, γ-rays, neutrons, and radioactive debris in augmenting ionospheric ionization are considered in turn. The most significant increases are at altitudes of 60-100 km, and the consequent modifications to VLF propagation and to the absorption and phase of HF signals traversing the region of enhanced ionization are examined. The general level of the paper is elementary, approximate, and tutorial.