Applications of Particle Accelerators

Of the tens of thousands of particle accelerators in operation worldwide, the vast majority are not used for particle physics, but instead for applications. Some applications such as radiotherapy for cancer treatment are well-known, while others are more surprising: food irradiation using electron beams, or the hardening of road tarmac. The uses of particle beams are constantly growing in number including in medicine, industry, security, environment, and cultural heritage preservation. This lecture aims to give a broad sweep of the many uses of particle accelerators, covering technologies ranging in size from a few centimetres for industrial electron linacs through to large synchrotron light sources of hundreds of metres circumference operating as national and international facilities. We finish by discussing some of the challenges facing accelerators used in wider society.