A FAST SWITCHING MIRROR UNIT FOR FLASH

Switching mirrors are used to provide several beamlines with Free Electron Laser or synchrotron radiation from one source. Since most users do not need the nominal bunch train density, a fast switching mirror is a method to supply many experimental groups. So far, the switching process has a duration of several minutes. A feasibility study at DESY analyzes possible ways of permanent switching at half of FLASH’s bunch train frequency of 1 to 10 per sec-ond. A first prototype with highest demands on repetition accuracy of the position (below 1 µm) and yawing of the mirror (about 1 arcsec) has been tested. In the course of the work several technical concepts from industry like Pro-grammable Logic Controllers or Position-Velocity Stream-ing found their way into beamline technology, thus allow-ing fast proceedings in development