The Paul Scherrer Institute in Villigen Switzerland is the largest Research Institute in Switzerland. It has four worldclass accelerators: two Proton Cyclotrons and two Electron Accelerators. They produce beams of neutrons, pions, muons and X-rays. These are used in Materials Sciences, Energy Research and Medical Applications. A special cyclotron is dedicated to irradiate tumours with protons. Over the last 22 years more than 8'000 cancer patients have been treated this way.

Autorentext
Werner Joho was born in Baden, Switzerland and lives now close to Baden. He studied physics at the Swiss Federal Institute (ETHZ) in Zurich and later got there his PHD. He worked first on the large Proton Cyclotron, which produces with 1.4 MW the largest beam power, world wide. Later he was involved with the Swiss Light Source (SLS), an electron storage ring, producing high quality X-rays. He spent some time at other accelerator facilities, like CERN, MSU in Michigan, TRIUMF in Vancouver Canada and Berkeley, California.