Spin-Dependence of Magnetic Dipole Gamma Radiation and the Nuclear Level Scheme of Pb208

Hulme, Mott, Oppenheimer and Taylor 1 remarked that a γ-ray due to a transition between levels of the same parity may be a mixture of magnetic dipole and electric quadripole radiations. This is possible when the change Δ I in the quantum number I for the total nuclear spin is ± 1 or 0. The relative proportions in the mixture will depend on the structure of the nucleus. For δ I = ±2, no parity change, magnetic dipole radiation is forbidden and nearly pure electric quadripole radiation will be emitted. An exception occurs if the spin change is 10, when the radiation must be pure magnetic dipole.