Micromachined silicon slits for beam-diagnostic in particle accelerators

We report the fabrication process of a silicon target with a rectangular slit as an instrument for measuring the size and the angular divergence of high charge-density electron beams in particles accelerators. Bulk micromachining of silicon wafers by means of anisotropic etching allowed the definition of slits with parallel straight edges and low disuniformity. The disuniformities of the completed device evaluated by scanning electron microscopy were found to be tolerable with respect to the wavelength used in the experiments.