So as to provide a target arrangement with improved mounting and dismounting ability, the target arrangement comprises a plate along a plane (E) which has a border (7) defined by a first wedge surface (5u) angled to the addressed general plane (E) and a second wedge surface (5l) which is substantially planar as well and angled with respect to the generic plane (E). The two wedge surfaces mutually convert in a direction along the addressed plane (E) and from a more central area of the plate outwardly.