fission product yields by mass for thermal neutron
fission of u-235
, a combination of the two typical of current nuclear power reactors, and u-233
used in the thorium cycle
ternary fission is a comparatively rare (0.2 to 0.4% of events) type of nuclear fission in which three charged products are produced rather than two. as in other nuclear fission processes, other uncharged particles such as multiple neutrons and gamma rays are produced in ternary fission.
ternary fission may happen during neutron-induced fission or in spontaneous fission (the type of radioactive decay). about 25% more ternary fission happens in spontaneous fission compared to the same fissioning system formed after thermal neutron capture, illustrating that these processes remain physically slightly different, even after the absorption of the neutron, possibly because of the extra energy present in the nuclear reaction system of thermal neutron-induced fission.
quaternary fission, at 1 per 10 million fissions, is also known (see below).