A Nanofabricated Wirescanner: Design, Fabrication and Experimental Results

Measuring the transverse size and profile of an electron beams is of crucial importance in modern accelerators, large colliders, free electron lasers and storage rings. Therefore several kinds of diagnostics have been developed to this purpose such as: optical transition radiation screens, scintillating screens, laser scanners and wire scanners. The last ones although providing only a multi shot projection in one plane of the beam, provide high resolution measurement. Wire scanners typically adopt wires with thickness of the order of 10 microns that are scanned across the beam, whilst ionizing radiation generated from the impact of the electrons with the wires is detected. In this paper we present a new wire scanner design, based on nanofabrication technologies. This original approach opens up new possibilities in term of wire shape, size, material and thickness with a potential for even higher resolution down to 1-2 microns leading to increased flexibility for instrumentation designers. After describing the device and its fabrication process, we report about our first measurements performed on the FERMI FEL electron beam.