Characterization and beam tests results of non-uniformly irradiated 3D pixel sensors for HEP experiments

3D Pixel detectors, with cylindrical electrodes that penetrate the silicon substrate, offer advantages over standard planar sensors in terms of radiation hardness, since the charge collection distance can be reduced independently of the bulk thickness. In the framework of the ATLAS Forward Physics (AFP) program, work has been carried out to study the suitability of 3D pixel devices for forward proton tracking. The AFP tracker unit will consist of an array of five pixel sensors placed at 2-3 mm from the Large Hadron Collider (LHC) proton beam. The proximity to the beam is essential for the AFP physics program as it directly increases the sensitivity of the experiment. Thus, there are two critical requirements for the AFP pixel detector. First, the dead region of the sensor has to be minimized. Second, the device has to be able to cope with a very inhomogeneous radiation distribution. Recent results of the characterization and beam test studies of in-homogeneously irradiated 3D pixel sensors produced at CNM-Barcelona will be presented.