CHARACTERISnCS OF NUCLEAR EXPLOSIONS

INTRODUCTION the ground, however, the term "shock" 1.01 An explosion, in general, reis used, because the effect is like that of suIts from the very rapid release of a a sudden impact. large amount of energy within a limited 1.02 Nuclear weapons are similar to space. This is true for a conventional those of more conventional types insofar "high explosive," such as TNT, as well as their destructive action is due mainly as for a nuclear (or atomic) explosion,' to blast or shock. On the other hand, although the energy is produced in quite there are several basic differences bedifferent ways \\\(§ 1.11). The sudden tween nuclear and high-explosive liberation of energy causes a considerweapons. In the first place, nuclear exable increase of temperature and presplosions can be many thousands (or sure, so that all the materials present are millions) of times more powerful than converted into hot, compressed gases. the largest conventional detonations. Since these gases are at very high temSecond, for the release of a given peratures and pressures, they expand amount of energy, the mass of a nuclear rapidly and thus initiate a pressure explosive would be much less than that wave, called a "shock wave," in the of a conventional high explosive. Consurrounding medium-air, water, or sequently, in the former case, there is a earth. The characteristic of a shock much smaller amount of material availwave is that there is (ideally) a sudden able in the weapon itself that is conincrease of pressure at the front, with a verted into the hot, compressed gases gradual decrease behind it, as shown in mentioned above. This results in someFig. 1.01. A shock wave in air is genwhat different mechanisms for the inierally referred to as a "blast wave" tiation of the blast wave. Third, the because it resembles and is accompantemperatures reached in a nuclear exied by a very strong wind. In water or in plosion are very much higher than in a