HECTOR: A code for the study of charged particles in axisymmetric tokamak plasmas. A new charged particle orbit following code HECTOR is described. The code simulates the behaviour of thermal particles and high energy particles, such as those resulting from the ICRF wave field interactions or from thermonuclear reactions within the confining magnetic fields of non- circular axisymmetric tokamak plasmas. The particle trajectories are traced using a new, fast, and efficient hybrid orbit-following scheme, based upon the drift equations in the guiding centre approximation and the constants of motion. The Monte Carlo technique is used to describe the Coulomb scattering processes of dynamical friction, pitch angle scattering, energy diffusion and the ICRF interaction processes. The code is specifically designed to operate within the experimental environment.