Needless to say, countries that possess and build nuclear bombs keep the process a secret. However, there are some basic facts about these weapons that are known.
Basic Design Types
A nuclear weapon design involves chemical, physical and engineering configurations. There are 3 types currently used, but the explosive power is all taken from nuclear fission.
The first type is the pure fission weapon. They are the only ones that have ever been utilized in war. The active component is plutonium (Pu-239) or fissile uranium (U-235).
These are set into a critical mass using the gun assembly or an implosion. The gun technique utilizes only uranium; the implosion method can use plutonium or uranium.
Fusion Boosted Fission Weapons
These were made to augment the implosion method. This weapon has deuterium and tritium gas (hydrogen isotopes). These components are heated up, producing a chain reaction and critical mass. The power is double that of the pure fission weapons.
Two-Stage Thermonuclear Weapons
These consist of a linked fission boosted fusion weapons. These are not the same as the weapons just mentioned though. This weapon has two stages on the chain.
The second stage is set off by energy from stage one. This makes the stage 2 explosion more powerful than the first. Theoretically it is possible to build nuclear bombs with more than two stages. However, the resulting explosions would be too powerful to be of any use.
Atomic Bombs and Hydrogen Bombs
Pure fission weapons are usually the first to be built by a country. Industrialized nations will have the 2 stage thermonuclear weapons. These are much more powerful and cost effective.
During its early history, the fission weapons were termed atomic bombs or A bombs. The popular press still refers to these weapons as such. However, it is actually a misnomer since the energy emanates from the atom nucleus only.
The nuclear weapons that use fusion are called hydrogen bombs or H bombs. Again this is a misnomer; the power is due to fission. The more accurate terms would be nuclear or thermonuclear weapons. The word thermonuclear is in reference to the temperature needed to start fusion.
The most powerful nuclear weapon ever made was the Tsar Bomba. Developed by the Soviet Union in the 1960s, it had a force equal to 50 megatons of TNT.
More and more countries have started to build nuclear bombs. Aside from the basic types mentioned, there are also cobalt and neutron bombs. Neutron bombs are capable of killing vast numbers of life forms using radiation.