[zeshkani]

i was reading on the nuclear fusion between deuterium and tritium the two isotopes of hydrogen, that they produce helium but also radioactive neutrons.

my question is how can a neutron become radioactive since it posses no charge,but still turns the neutron radioactive. i know that the two postive particles have to fuse and overcome the coulomb barrier, and that helium alpha particles are produced also in the reaction in which later they can or might self ignite the reaction, but anyhow how are the neutrons becoming radioactive ?

[pantone159]

Well, free neutrons (i.e. not bound in a nucleus) will beta decay into proton + electron + antineutrino, so I guess they are technically radioactive.  Also, when absorbed by other nuclei, they often create a radioactive isotope.

[Borek]

IMHO you are mistaking rays with radioactivity. Neutrons are not radioactive (well, Mark is right about their decay), neutrons are one of types of rays sent, just like alpha particles.

Warning: vocabulary alert I am not sure if I am properly using 'rays' here.

[pantone159]

Yeah, maybe 'neutron radiation' is a better term than 'radioactive neutrons'.

[Elgon]

My guess is that somebody confused the radioactivity induced by the neutrons with the neutrons themselves being radioactive.

The large amount of neutrons emitted in the fusion process has to be captured by the walls of the planned fusion reactor. Due to the radioactive isotopes created in the capture process, the walls themselves become radioactive as well. The only good thing is that the half-life (and subsequent radiotoxicity) of the waste generated in a fusion reactor is significantly shorter than the half-life of waste from a nuclear power plant.