Positioning of diffuse metallic target with a point diffractive interferometer

Abstract

Proton acceleration obtained by focusing an ultraintense ultrafast laser beam presents the technological and metrological challenge of correctly placing diffuse metallic target at the focus of the laser beam. In this work we present the use of the Point diffractive interferometer for solving this problem. We studied the accuracy and precision of the system at repositioning the metallic target after displacing and horizontally tilting the target out of its reference position. We achieved an accuracy at repositioning the target at its reference position of 1.50 µm and 6 arcmin with a precision of 1.40 µm and 5.7 arcmin. Our work shows the high accuracy provided by a system as simple as the Point Diffraction interferometer even at positioning surfaces with diffuse reflection.