Production and Properties of Radiation

Abstract

Electromagnetic radiation is used in radiation therapy for its unique properties and relative ease of production compared to other forms of particle radiation. Particles are directly ionizing while electromagnetic radiation is indirectly ionizing because it sets other particles in motion to deposit the dose. The majority of innovation in radiation therapy has focused on electromagnetic radiation, beginning with X-ray tubes and $γ$-rays emitted from man-made radioisotopes. Later on, with the development of the waveguide and accelerator tube came the linear accelerator and the microtron, which offered the ability to deliver photons and electrons in the megavoltage energy range. More recently, electromagnets were developed to be powerful enough to accelerate heavier particles to extremely high energies in a cyclotron or a synchrotron for particle beam therapy.