High-resolution mapping of secondary cosmic rays with miniaturised stacked pixel telescope

We performed detailed measurements of the secondary cosmic ray field in the lower atmosphere (at 200 m). We use a miniaturised particle telescope consisting of two closely stacked synchronised Timepix3 detectors. Position-, spectral-, and time-sensitive particle tracking provides enhanced particle-type resolving power and high angular resolution mapping of charged particles. Evaluation and calibration of the telescope synchronised tracking and directional response was performed with proton and electron beams. The telescope architecture, modeled angular response and developed data analysis provide accurate composition characterisation and high-angular resolution directional mapping of the charged particle component. In particular, the muon component can be resolved to a high degree over the photon and electron components in the lower atmosphere. The muon angular flux is measured in a wide field of view with enhanced discrimination.