Question
Why is it necessary to slow down the neutrons, produced through the fission of nuclei (by neutrons), to sustain a chain reaction? What type of nuclei are (preferably) needed for slowing down fast neutrons?
Solution
Slow neutrons have a much higher intrinsic probability of inducing fission in than fast neutrons.
Any substance which is used to slow down fast moving neutrons to thermal energies is called a moderator. Moderators are provided along with the fissionable nuclei for slowing down fast neutrons.
The commonly used moderators are water, heavy water (D2O) and graphite.
Any substance which is used to slow down fast moving neutrons to thermal energies is called a moderator. Moderators are provided along with the fissionable nuclei for slowing down fast neutrons.
The commonly used moderators are water, heavy water (D2O) and graphite.
