Hard Science

The 5 Key Differences Between Atomic Bombs and Hydrogen Bombs

The hydrogen bomb has once again claimed front page headlines, having been (allegedly) detonated in a test by North Korea.

But how does a hydrogen bomb differ from an atomic bomb?

Here’s all that would make it clear to you.

1. The Process

A.Bomb: An atomic bomb relies on nuclear fission, a reaction in which the nucleus of an atom is split, which releases a great deal of nuclear energy.


H.Bomb: A hydrogen bomb relies on nuclear fusion, whereby two atomic nuclei collide u..t a very high speed, which joins them and forms a new type of nucleus.


2. How it Works

A. Bomb: Atomic bombs are also known as fission bombs: fission material such as uranium or plutonium is combined into what Is known as a supercritical mass, or the amount of material needed to begin a nuclear chain reaction. When detonated, the explosive material in the bomb sets off a nuclear chain reaction that causes the explosion.


H.Bomb: Hydrogen bombs are thermonuclear bombs: a fission bomb is placed inside a radiation-reflecting container with a fusion fuel,  like tritium or deuterium.  These two materials – tritium and deuterium – are isotopes of hydrogen (hence the bomb’s name).  The explosive material, the fission bomb, detonates and causes the primary reaction. It then compresses and heats the fusion fuel which causes further chain reactions, known as the secondary reaction.


Note that both these fission and fusion processes occur almost instantaneously.

3. Explosive Yield


A Bomb: Yields of nuclear explosions are hard to determine, even when using rough estimates in the  kiloton or megaton range.

For fission devices, yield value is calculated from “radiochemical/fallout analysis”, or the quantity of fission products that are generated in the blast.

For both fission and fusion explosions, yields can be inferred based on blast size, infrasound firewall brightness, seismographic data, and shock wave strength.

The two atomic bombs dropped on Hiroshima and Nagasaki exploded with forces equivalent to 15,000 and 20,000 tons of TNT, respectively.

Hydrogen bombs are thousands of times more powerful than their atomic counterparts.


4. First Tests

Atomic Bomb: Codenamed Trinity was the first fission device test using plutonium implosion detonation conducted by the United States Army on July 16, 1945 at the Jornada del Muerto desert in New Mexico. It had an estimated explosive yield of 20 kilotons of TNT.


Hydrogen Bomb: ‘lvy mike’ was the first successful test of a full-scale thermonuclear device, detonated on November 1, 1952 by the United States on Enewetak, an atoll in the Pacific Ocean. It produced an estimated exclusive yield in the range of 10.4 to 12 megatons of TNT.


5. Most Powerful Versions

Atomic Bomb: ‘Ivy king’ was the largest fission nuclear bomb tested by the United States. It was dropped from B-36H Bomber on November 16, 1952 at Runit island in the Enewetak atoll, resulting in a 500 kiloton explosion.


Hydrogen Bomb: ‘Tsar Bomba’ was the nickname for the AN602 hydrogen bomb tested on   October 30, 1961 by the Soviet Union at the Mityushikha Bay in the Arctic Circle. It was the Most powerful Nuclear weapon ever detonated and remains the most powerful man made explosion in human history it had a  yield of 50 megaton TNT.