When nuclei collide, the interaction may result in products different from the original nuclei. The total momentum and angular momentum, however, will remain the same after the reaction. The total number of nucleons also remains unchanged, also the total electric charge. A small but significant amount of mass (up to 1%) may be transformed into energy, or vice versa, during a reaction, but the total mass-energy relationship is conserved as well. You can use ,the famous equation by Einstein. The conversion factor for mass into energy is the square of the velocity of light, as in , where C is the velocity--an extremely large number.

In the model of nuclear reactions of Niels BOHR, a bombarding particle penetrates a nucleus to form an intermediate compound nucleus that lasts only long enough for the energy and momentum of the incident particle to be transferred among all the nucleons. The system decays by emission of neutrons, protons, and other particles, referred to as the evaporated particles. If a given compound nucleus is formed by different bombarding particles and target nuclei but at the same total energy, the products of the reaction will remain the same.

In the direct interaction model, the incident particle is assumed to pass through the target nucleus somewhat freely and to interact directly with only one or a small number of nucleons. The struck particle is ejected from the nucleus, and the incident particle may too reemerge. At high bombarding energies the incident particle may leave residual energy for compound nucleus evaporation products and may eject sizable fragments from the target.

Bookmark This Page