A dusty nuclear explosion scene

After a nuclear explosion, a glowing fireball is first produced, and then a mushroom-like smoke cloud is produced. This is a typical sign of a nuclear explosion. When a fireball nuclear weapon explodes in the air at a certain height from the ground, the high-temperature and high-pressure projectile expands rapidly around, and the surrounding cold air is heated by X-ray radiation. The characteristics of hot air absorbing high temperature radiation make the heated and pressurized hot air mass become a sphere with roughly uniform temperature, and both temperature and pressure have abrupt fronts. This hot air mass is called an isothermal fireball. The fireball (see color diagram [nuclear explosion fireball and shock wave]) emits light radiation, which expands rapidly while the temperature and pressure gradually decrease. When the temperature drops to 3× 10, a shock wave moves around at a speed of 40 ~ 50 km/s, and its front (that is, the front of the fireball) still shines. After the shock wave is formed, the temperature distribution surface inside the fireball is low and gradually increases inward, and there is a high-temperature core with uniform temperature inside the fireball. When the temperature of shock wave front is slightly higher than 2000 K, the shock wave leaves the fireball and propagates outward according to the mechanical law, and then its front no longer emits light.

After the fireball goes out, the mushroom cloud forms a rising smoke cloud. The reflection of the shock wave near the projection point of the explosion center and the suction of the negative phase make the ground raise a huge dust column, and the rising dust column is connected with the smoke cloud to form a high mushroom-shaped smoke cloud (mushroom cloud for short).