60 likes | 201 Views
Nuclear Physics. Selected Topics 4 – Nuclear Reactions. The structure of nuclei can be changed by bombarding them with energetic particles. The changes are called nuclear reactions. As with nuclear decays, the atomic numbers and mass numbers must balance on both sides of the equation.
E N D
Nuclear Physics Selected Topics 4 – Nuclear Reactions
The structure of nuclei can be changed by bombarding them with energetic particles. • The changes are called nuclear reactions. • As with nuclear decays, the atomic numbers and mass numbers must balance on both sides of the equation.
Alpha particle colliding with nitrogen: Balancing the equation allows for the identification of X: So the reaction is
“Target” particles may be bombarded with a, neutrons, protons, deuterons, gamma. General scheme: a + X Y + b Energy released: Q = (Ma + MX – My – Mb).c2
Calculate Q for some reactions. Dm (in u) = 1.007825 + 7.016003 – (2)(4.002602) = 1.8624 u = 17.3 meV This energy is the kinetic energy of the products.
Calculate Q for some reactions. Dm = 1.007825 + 7.016003 – 7.016928 – 1.008665 = -.001765 u = -1.644 meV The incident particle must have a minimum kinetic energy. Here, m = 1.007825 u and M = 7.016003 u.