Initial and final state radiation Initial and final state radiation In particle physics, initial and final state radiation refers to certain kinds of radiative emissions that are not due to particle annihilation. It is important in experimental and theoretical studies of interactions at particle colliders. Particle accelerators and colliders produce collisions (interactions) of particles (like the electron or the proton). In the terminology of the quantum state, the colliding particles form the "Initial State". In the collision, particles can be annihilated or/and exchanged, producing possibly different sets of particles, the "Final States". The Initial and Final States of the interaction relate through the so-called scattering
United Nations Scientific Committee on the Effects of Atomic Radiation United Nations Scientific Committee on the Effects of Atomic Radiation The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) was set up by resolution of the United Nations General Assembly in 1955. 21 states are designated to provide scientists to serve as members of the committee which holds formal meetings (sessions) annually and submits a report to the General Assembly. The organisation has no power to set radiation standards nor to make recommendations in regard to nuclear testing. It was established solely to "define precisely the present exposure of the population of the world to ionizing radiation."