TABLE OF CONTENTS In previous chapters we indicated that many nuclei are unstable and often emit ?, ? or ? particles. We will now discuss several more quantitative aspects of nuclear radioactivity and its historical impact on our understanding of nuclear structure and nuclear transmutation.
As we have seen before, ?-decay represents the disintegration of a parent nucleus to a daughter through the emission of the nucleus of a helium atom, and the transition can be characterized as
| (4.1) |  |
As we will see in Chapter 5, ?-decay can be regarded as the spontaneous fission of the parent nucleus into two daughter nuclei with highly asymmetric masses. If we assume that the parent nucleus is initially at rest, then conservation of energy requires
| (4.2) |  |
where M P, M D and M ? are the masses of the parent, daughter and the ?-particle, respectively. Similarly, T D and T ? represent the kinetic energies of the daughter and of the ?-particle. Equation (4.2) can also be rewritten as
| (4.3) |  |
Although the right hand side of Eq. (4.3) involves nuclear masses, we can, in fact, use atomic masses in the expression since the masses of the electrons cancel. Thus, we can write
| (4.4) |  |
where we have defined the disintegration energy or Q-value as the difference in the rest masses of the initial and final states. It is clear that Q also equals the sum of the...
