A NEW LOW INTENSITY BEAM PROFILER FOR SPIRAL2

In the framework of SPIRAL 2 ion beams, several beam profile monitors are presently being developed at GANIL. One of them is a low-intensity beam-profile monitor that works as a secondary electron detector. This Emission-Foil Monitor (EFM) will be used in the radioactive beam lines of SPIRAL2 and in the experimental rooms of this new facility. The ions produce secondary electrons when they are stopped in an aluminium emissive foil. The electrons are then accelerated using an electric field and guided using a magnetic field to a double-stage microchannel plate (MCP). A 2D pixellated pad plane placed below the MCP is used to collect the signals. The magnetic field created by permanent magnets in a closed magnetic circuit configuration permits the beam-profile reconstruction to be achieved with a good resolution. The EFM can visualize beam-profile intensities between only a few pps to as much as 109 pps and with energies as low as several keV. This profiler has been under development since 2009 and is currently manufactured. Recent results of this monitor are presented in this article