A system for measuring the electron beam profile and position inside the undulator for the ELBE FEL

In the Forschungszentrum Rossendorf (FZR), an infrared FEL at the radiation source ELBE is under construction. For the measurements of the electron beam position in the undulator, two systems will be used. The first one consists of seven insertable beryllium OTR (Optical Transition Radiation) view screens, which will also be used for the alignment of the FEL optical resonator. The second one will use a single moveable YAG (Yttrium Aluminium Garnet activated by Cerium) screen, which can travel within the undulator vacuum chamber such that the electron beam position can be measured at any place in the undulator.