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Name: Yohann
Status: student
Age: 13
Location: N/A
Country: N/A
Date: 6/22/2004

Can you split a neutron?

Well, Yohann, if you put a neutron free in space and wait about 700 seconds, it will split itself for you! Surprise, neutrons are unstable, when they are not in a nucleus.

Out comes a proton, an electron, and a nearly undetectable neutrino. (

The kinetic energy of these particles totals 0.78 MeV. The energy-equivalent of the mass of an electron is 0.51MeV. So 0.78 MeV is enough raw energy to make a whole new electron, but not enough to make an electron/positron pair, which is the minimum combination needed.

If you slowly bump two neutrons together with less than 1MeV energy, I think they will do a kind of fusion reaction. One will make the other decay right now, spitting away a fast electron. (and neutrino, true. a Gamma Ray photon too?) Then you will have a deuterium nucleus (a proton and neutron bound together, permanently stable), and a free electron.

So you will probably want to try smashing particles into a neutron to make it split, using 10MeV-100GeV kinetic energy. This will add enough energy to make a whole bunch of new particles in the shower resulting from the collision. So is that splitting the neutron, or just making junk?

By the way, the mass of a neutron or proton is roughly 1000MeV (1GeV). That's how much energy it takes to make one.

After decades of colliding particles and looking for patterns in the junk, we have a theory. Theory has it that the neutron has three "quarks" inside. The proton has a different set of three. In a collision you can mix up those quarks, and/or create new matched pairs of a quark and its anti-quark, and rearrange them into new sets of quarks, and each bundle of quarks that flies away will look like some better-known particle. Like another electron.

But you cannot get one quark out by itself. It seems that would take more energy than making dozens of new neutrons from pure energy. How much more, I am not sure we know yet. Or maybe it cannot be done at any cost. Maybe quarks do not really exist, they are just a human-thought logic-token for one end of a tiny twist in space that cannot exist without another, complimentary end.

Splitting neutrons kind of looses meaning after that.

So, no, we can do corporate-style liquidation of a neutron's assets, but we cannot split it.

Jim Swenson

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