A thermonuclear bomb, also known as a hydrogen bomb or H-bomb, is a powerful weapon that derives its immense explosive force from an uncontrolled self-sustaining chain reaction involving isotopes of hydrogen combining at extremely high temperatures to form helium through nuclear fusion. The high temperature required for this fusion reaction is generated by detonating an atomic bomb.
Features of a Thermonuclear Bomb:
A key distinction between a thermonuclear bomb and an atomic bomb lies in the energy release mechanism. A thermonuclear bomb utilizes the energy produced when two lighter atomic nuclei combine or fuse to form a heavier nucleus.
On the other hand, an atomic bomb harnesses the energy released when a heavy atomic nucleus splits, or undergoes fission, into two lighter nuclei. Under normal conditions, atomic nuclei have positive electrical charges that strongly repel other nuclei, preventing them from coming close to each other.
However, only under temperatures of millions of degrees, do the positively charged nuclei acquire sufficient kinetic energy or momentum to overcome their mutual electrical repulsion and fuse together, thanks to the attraction of the short-range nuclear force.
The hydrogen nuclei, being very light, are ideal candidates for this fusion process as they have weak positive charges and offer little resistance to overcome.
During the fusion process, the hydrogen nuclei that combine to form heavier helium nuclei must lose a small fraction of their mass (about 0.63 percent) to “fit together” into a larger atom. This mass is converted entirely into energy, as explained by Albert Einstein’s famous formula: E = mc^2. According to this equation, the amount of energy created is equal to the mass multiplied by the square of the speed of light. This energy is what constitutes the explosive power of the hydrogen bomb.
Deuterium and tritium, which are isotopes of hydrogen, serve as ideal interaction nuclei for the fusion process. Two atoms of deuterium, each with one proton and one neutron, or tritium, with one proton and two neutrons, combine during the fusion process to form a heavy helium nucleus containing two protons and one or two neutrons.
In current thermonuclear bombs, lithium-6 deuteride is used as the fusion fuel, which is converted to tritium early in the fusion process.
Explosive process:
In a thermonuclear bomb, the detonation process begins with a primary stage containing a relatively small amount of conventional explosives. The detonation brings together enough fissile uranium to initiate a fission chain reaction, resulting in another explosion and temperatures of several million degrees.
The force and heat of this initial explosion are then directed to the secondary stage, which comprises lithium-6 deuteride. The tremendous heat generated initiates fusion, leading to the explosion of the secondary stage and separation of the uranium container.
The neutrons released during the fusion reaction cause the uranium container to undergo fission, which often accounts for most of the energy released from the explosion, and also produces fallout (deposition of radioactive material from the atmosphere) in the process.
(A neutron bomb is a thermonuclear device where the uranium container is absent, resulting in a very short explosion but a lethal “enhanced radiation” of neutrons.) The full chain of explosions in a thermonuclear bomb takes just a fraction of a second to occur.
Impact of a thermonuclear explosion:
A thermonuclear explosion produces varying amounts of explosions, light, heat, and fallout. The force of the explosion takes the form of a shock wave traveling at supersonic speed from the point of detonation, capable of completely destroying buildings within a radius of several miles.
The intense white light of the explosion can cause permanent blindness to observers many miles away. The heat from the explosion ignites wood and other flammable materials over large distances, leading to widespread fires. Radioactive fallout contaminates air, water, and soil, persisting for years after the explosion, and its distribution can be worldwide.
Thermonuclear bombs possess hundreds or even thousands of times more power than atomic bombs. The explosive yield of atomic bombs is measured in kilotons, with each unit equaling the explosive force of 1,000 tons of TNT. In contrast, the explosive power of hydrogen bombs is commonly expressed in megatons, with each unit equivalent to the explosive force of 1,000,000 tons of TNT.
Some hydrogen bombs with over 50 megatons of power have been detonated, but the weapons mounted on strategic missiles typically range from 100 kilotons to 1.5 megatons. These thermonuclear bombs can be miniaturized enough (a few feet long) to fit into the warheads of intercontinental ballistic missiles, which can traverse almost halfway across the globe in 20 or 25 minutes. Additionally, these missiles are equipped with highly accurate computerized guidance systems, enabling them to land within a few hundred yards of their designated targets.
Who developed Hydrogen Bomb
The first hydrogen bomb was developed by American scientists, including Edward Teller and Stanislaw M. Ulam, and was tested at Enewetak Atoll on November 1, 1952. The Soviet Union conducted its first hydrogen bomb test on August 12, 1953, followed by the United Kingdom in May 1957, China in 1967, and France in 1968. India conducted a test of what was believed to be a thermonuclear device in 1998.
During the late 1980s, there were approximately 40,000 thermonuclear devices in the arsenals of nuclear-armed nations worldwide. However, this number declined during the 1990s. The immense destructive potential of these weapons has been a major concern for the global population and its leaders since the 1950s, leading to discussions and efforts on arms control.