Is it possible to produce the inverse of a decay?

[marcgrissz]

Is it possible to produce the inverse of a natural radioactive decay? If yes, what would happen? Release energy?

 

[Bystander]

what would happen?

Since the decay releases energy, if you put energy into the system, say in a nova or supernova, you can call that an inverse decay, or more correctly nucleosynthesis.

 

[nikkkom]

Is it possible to produce the inverse of a natural radioactive decay? If yes, what would happen? Release energy?

Yes. Every decay is reversible.

A "reverse decay" would be a collision of two particles resulting in creation of one particle, whose rest mass is bigger than the initial two particles' masses.

For example, direct a sufficiently energetic electron beam into hydrogen and you can create a few neutrons...

 

[mfb]

Yes. Every decay is reversible.

A "reverse decay" would be a collision of two particles resulting in creation of one particle, whose rest mass is bigger than the initial two particles' masses.

For example, direct a sufficiently energetic electron beam into hydrogen and you can create a few neutrons...

That would still emit a neutrino.

Exactly reversing a decay (1 to many particles) is tricky - you have to collide multiple particles with exactly* the right energy to get this 1 particle out and nothing else.

*within the natural uncertainty of the energy of this particle which increases with shorter lifetime, so it is much easier with short-living particles like the Z boson.

 

[nikkkom]

That would still emit a neutrino.

I didn't want to be cruel and ask him to create an apparatus which emits beams of W bosons :)

 

[nuclear_chris]

Yes, though I would not call that inverse decay. Fusion might be a more appropriate term and their would be release of energy.If you look at the nuclear binding energy curve, you'll see that low Z elements are most likely to undergo fusion, where as heavier elements are likely to undergo decay.