Mechanical model of radioactive decay.

Mechanical model of radioactive decay. Ref.:Modern College Physics by Harvey White, 3rd ed., p. 768-772 This demo is a mechanical model of a nucleus for demonstrating a) the increased kinetic energy of nuclear particles after a capture, and b) the chance probability of radioactive decay or disintegration by the ejection of a particle. There is a somewhat flattened potential barrier surrounding a 'nucleus' of steel balls that are constantly agitated by an rotating eccentric pin. A steel ball rolls down a ramp and moves into the group of moving balls. After a number of collisions another ball usually is knocked out the other side of the nucleus. This is analogous to a proton going in and a neutron coming out. Even if no particle is ejected immediately, the kinetic energy of the set of balls is increased somewhat, increasing the likelihood of the emission of a particle. If the motor is left running, a single ball will be hit by several balls moving in the same direction and will recoil with enough speed to carry it over the potential barrier. Note: start with Variac set at 105 volts and 15-25 balls set in the 'nucleus'. Fig. 1 represents graphical models of the nucleus proposed by Gamow. To an approaching positive charge, the potential barrier of a nucleus is analogous to the crater of a volcano. In the stable nucleus, the particles are moving slowly at the bottom of the volcano pit. When a proton or