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FLASH at DESY in Hamburg is a linear accelerator, which uses superconducting technology to produce soft x-ray laser light ranging from 4.1 to 45 nm. To ensure the operation stability of FLASH, monitoring of the beam is mandatory. Two Ionization Profile Monitors (IPM) detect the lateral x and y position changes. The functional principle of the IPM is based on the detection of particles, generated by interaction of the beam with the residual gas in the beam line. The newly designed IPM enables the combined determination of the horizontal and vertical position as well as the profile. This is made possible by a compact monitor, consisting of a cage in a vacuum chamber, two micro-channel plates (MCP) and two repeller plates with toggled electric fields at the opposite sides of the MCPs. The particles created by the FEL beam, drift in a homogenous electrical field towards the respective MCP, which produces an image of the beam profile on an attached phosphor screen. A camera for each MCP is used for evaluation. This indirect detection scheme operates over a wide dynamic range and allows the detection of the center of gravity and the shape of the beam. The final design is presented.
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