Lawrence’s cyclotron accelerator containing two hollow "D"-shaped sheet metal electrodes called "dees" inside a vacuum chamber. The dees are placed face to face with a narrow gap in between, the cylindrical gap is there for the particles to move, causes magnetic field. The magnetic field makes the particles path to bend and become circular due to the Lorentz force perpendicular to their direction of motion. If the particles move in a constant speed, they would travel in a circular path within the dees under the magnetic field. However, if a radio frequency carries thousands volts is applied between gap. Every time after the particles pass to the other electrode the polarity of the frequency voltage is reverse, this is would leads to an electric field. The electric field accelerating the particles that move across the gap, hence the speed of the particles is increasing causes them to move in a larger radius circle with each rotation. Therefore, the particles move in a spiral path from the centre toward the rim of the dees. The cyclotron accelerator is a high performance machine which can be use continuously and effectively; however, the energy is not very high.