Did you know that particle accelerators play an important role in many functions of todays society and that there are over 30 000 accelerators in operation worldwide? A few examples are accelerators for radiotherapy which are the largest application of accelerators, altogether with more than 11000 accelerators worldwide. These accelerators range from very compact electron linear accelerators with a length of only about 1 m to large carbon ion synchrotrons with a circumference of more than 50 m and a huge rotating carbon ion gantry with a weight of 600 tons!
There are also a growing number of synchrotron light sources in the world. The light in these sources are created by electrons that are accelerated to almost the speed of light. This light can reveal the molecular structures of materials and also take x-ray pictures of the inner structure of objects. Synchrotron light sources are very important in life sciences, material sciences and chemistry. Another type of accelerators are used in spallation sources, like the European Spallation Source in Lund, Sweden. Here protons are accelerated to very large energies. They produce neutrons when they are smashed into a disc of tungsten. These neutrons are used for finding the inner structure of objects and atomic structures of materials. Finally there are many accelerators for basic physics, like the large hadron collider in Cern.
