In May 2007, a Helmholtz-University Young Investigators Group for the study of coherent THz radiation from ultra-short bunches in electron storage rings has been established at Forschungszentrum Karlsruhe and Universität Karslruhe (TH), which have now fused to form the KIT - Karlsruhe Institute of Technology. The strong scientific case for THz radiation is illustrated by many applications in various fields such as solid state physics, biology and nano technology. The THz region lies above the frequencies of traditional electronics but below the range of optical and infrared generators. Up to now, possibilities to generate sufficiently intense and brilliant radiation of the wavelengths in question were scarce and the region was therefore named the “THz gap”.