PHYS 0847 Lecture 5: Physics - Chapter 5
Document Summary
When a radioactive nucleus decays (as described in chapter 4), it releases a lot of energy. But radioactive decay generally happens according to the half-life rule very slowly for most commonly found radioactive materials. Get a neutron to stick to the nucleus to make it even more unstable and stimulate the decay. Problem: it needs a neutron to trigger a reaction. So just feed these neutrons back and use them to trigger even more reactions. When uranium-235 decays, it produces not only fission fragments but also neutrons. These neutrons could stick to other radioactive nuclei and cause more neutron activation. Suppose i had a 10kg (22lbs) brick of u-235. I stimulate the decay of one single u-235 atom. A (cid:272)hai(cid:374) rea(cid:272)tio(cid:374) is a(cid:374) e(cid:454)a(cid:373)ple of (cid:862)e(cid:454)po(cid:374)e(cid:374)tial gro(cid:449)th(cid:863). Examples: compound interest, growth of a fetus, population, cancer cells, viruses, bacteria, Pcr polymerase chain reaction which is copying itself a few times to create more dna.
