Cyclotron is an instrument devised by Ernest Orlando Lawrence in 1929. He was awarded Nobel prize in 1939 for its invention and use in the production of artificially radioactive elements. The device consists of a vacuum chamber between two circular poles of a huge electric magnet enclosing two dees (i.e. split halves of a hollow disc) and with a negative charged plate on its rim. A positively charged practicle produced at the centre of the chamber is forced to move in a curved path by rapid alteration of charges on the dees and alternate irgpulaion and attraction of the particle. The velocity and radius of curved path of the particle increases till it flies out through a window in dees and can attack different elements to be used as target and cause nuclear chemical reactions.