4. Ion impact localization and image reconstruction

4.1 Impact location

3D atomic probes owe their development to a position-sensitive, time-resolved detector. In addition to time of flight, the detector provides the position of ion impacts (X, Y ). Depending on the detector used, localization accuracy can reach 100 μm. Various technologies have been developed since the first instruments were introduced in the 1990s. Today's detectors consist of a set of two crossed delay lines (coiled lines, figure 5 ). These are placed behind a pair of microchannel wafers (charge amplifiers) that transform the impact of an ion (q = ne with n = 1, 2, 3...) into a spray of electrons (n = some 10 ⁷ ) that irradiates...