A nanofabricated wirescanner: Design, fabrication and experimental results

Measuring the transverse size of electron beams is of crucial importance in modern accelerators, from large colliders to free electron lasers to storage rings. For this reason several kind of diagnostics have been developed such as: optical transition radiation screens, scintillating screens, laser scanners and wirescanners. The last ones although providing only a multishot profile in one plane have proven capable of very high resolution. Wirescanners employ thin wires with typical thickness of the order of tens of microns that are scanner across the beam, whilst ionizing radiation generated from the impact of the electrons with the wires is detected. In this paper we describe a new approach to wirescanners design based on nanofabrication technologies. This approach opens up new possibilities in term of wires shape, size, material and thickness with potential for even higher resolution and increase flexibility for instrumentation designers. We describe the device, the fabrication process and report measurement performed on the FERMI FEL electron beam.