Nuclear radiation

8.3 Nuclear radiation and transmutations:

1. N-Z curve    Island of stability    Neutrons to protons ratio

2. Too many nucleons:

   • Alpha radiation

   • Spontaneous fission

3. Too many neutrons:

   • Neutron ejection

   • Beta minus decay  or electron emission   Z -> Z +1

4. Too many protons:

   • Proton ejection

   • Beta plus decay   or positron emission   Z -> Z -1       

   • K capture (no positron  is emitted but Z -> Z -1)  proton capture   electron and transform into a neutron and  X-ray photons characteristic for the daughter atom  is emitted   

5. Too much energy:

   • Gamma photon  is emitted  from excited nucleus

   • Internal conversion gamma photon  from excited nucleus dislodge inner shell electron

8.5 Propagation of the radiation:

1. Inverse square law         Intensity and attenuation of the radiation

2. Collimation and divergence      Intrinsic decay

3. Absorption      Scattering