Superconducting radio frequency (SRF) cavities for particle accelerators are fabricated using high purity niobium to allow for continuous high power operation. A hot-spot generated at a surface defect during accelerator operation can quench superconductivity and limit its performance. Increased heat conduction to the liquid helium bath dissipates hot spots, maintaining performance. Properly tre...

The V-code development has been motivated by the necessity of a powerful tool for the beam dynamics on-line simulation. Based on the Ensemble model [1], the V-code provides the possibility of fast and efficient beam dynamics simulation. Such a tool is as important for the accelerator commissioning as for the operating machine. The main principles of the code are the complete accelerator simulat...

A description of the TESLA Test Facility, which has been set up at DESY by the TESLA Collaboration, will be given. Measurements of the superconducting 9-cell cavities in vertical and horizontal test cryostats will be presented, as well as the experience with the first two accelerator modules in the TTF linac. Future cavity R&D efforts will be described.