How come don’t particle accelerators just blow up?


When we try to make new elements and launch atoms at one another they don’t blow up, but when you do that in a nuclear device it ruin’s cities

In: 0

>When we try to make new elements and launch atoms at one another they don’t blow up, but when you do that in a nuclear device it ruin’s cities

When you inhale a single water molecule you won’t even notice it. When you dump 10^30 molecules of water over your head you may drown.

Nuclear bombs release the energy from a chain reaction involving trillions of trillions of particles. Particle accelerators don’t.

A nuclear device contains a lot of fissile material. A single atom splitting doesn’t release a lot of energy. However, when there are other unstable atoms nearby, they get hit by the “debris” from the splitting atom, splitting them as well, resulting in a chain reaction that splits trillions of atoms, resulting in a lot of energy being released.

The nuclear bomb that detonated over Hiroshima contained 64 kg of Uranium. Less than 1 kg of it went through fission. The amount of released energy was 15 kilotons of TNT which is equal to 63 Terajoule = 63 * 10^12 = 63,000,000,000,000 Joules

One joule is the energy something with 1 Watts used each second. So a 10 Watt lamp uses 10 joules each second. A human generates around 100W of heat to 100 joules every second. A candle is around 80 W or 80 joules per second

One mole of Uranium-235 has a mass of 235 grams so around 4 moles of Uranium-235 atoms went through fusion.

A mole is just a number of objects like a million, it is a very large number of objects. It is defined as exactly 6.02214076×10^23 =602,214,076,000,000,000,000,000 or 602 thousand billion billion. Les just use 6 x 10 ^23 for simplicity

If you look at the energy number compared to the number of atoms it is quite clear that the number of atoms required to release 1 Joule of energy is large.

If we calculate the number of Uranium-235 that need to go through fission to release 1 joule it is 4 x 6×10^23 / (63 x 10^12 ) = 3.8 x 10 ^10 = 38 billion 38,000,000,000

If you compare it to a candle it releases the same amount of energy as 3 trillion Uranium-235 that undergo fission every second.

So if you just use keep the number of atoms in the particle accelerator not too high the amount of energy in it is not that high.

It can still be a relatively large amount of energy. If you look at the Large Hadron Collider has 2556 bunches of proton in the accelerator and each beam has 115 billion protons the total energy in a beam is 300 million Joules. They know how it will interact and the rate energy is released and has designed the device so it can handle it.

The truth is that it depends on what atom is colliding into what other atom – and how many of these collisions you make happen all at once.


Some combinations, when they collide, will simply glob together into a new bigger atom.

Other combinations, when they collide, will glob together for an instant but then fall apart in new way that leaves two big (but different to the original) atoms while releasing some energy.

Other combinations, when they collide, will just shatter into many little pieces releasing lots of energy in the process.


The reason that nuclear devices make big explosions is because scientists/engineers very specifically chose a combination that is known to shatter apart very energetically – and then they got pounds and pounds of these atoms together so that a lot of those collisions will happen very quickly.

The reason why a particle accelerator doesn’t explode is because (even when they’re studying one of these high-energy-releasing combinations) they are throwing so few atoms together at once that it is basically a tiny microscopic firework rather than a big bomb.