An Ionization Profile Monitor for the determination of the FLASH photon beam parameter

For the diagnostics of Free Electron Laser (FEL) it is necessary to obtain accurate information on the position and profile of the electron and/or the photon beam. For these tasks, one promising method is the use of the so-called Ionization Profile Monitor (IPM). An essential advantage of this method is that the FEL beam is not influenced by the IPM, so it is possible to analyze the beam parameters without beam destruction. Moreover, the monitor is able to determine the relative position and the spatial profile of the photon beam with the precision of a few mu m. In this paper, the design and first implementation of an Ionization Profile Monitor as a photon diagnostic tool at the FLASH accelerator in Hamburg is presented. In addition, the first measurements taken at FLASH are analyzed and good measuring accuracy of the IPM is obtained. (C) 2010 Elsevier B.V. All rights reserved.