silicon drift detectors 2d particle tracking Large Area Silicon Drift Detectors for X-ray spectroscopy, timing and imaging designed by INFN Trieste and developed in collaboration with INAF (IAPS Rome, IASF Bo), Fondazione Bruno Kessler, PoliMi, University of Pavia, University of Bologna >10 yrs R&D Two side planar process on high resistivity (FZ or NTD) n-type Silicon Linearly scaling potentials are applied to drift cathodes by means of an integrated voltage divider to generate a constant electric field parallel to the detector surface directed outwards an array of anodes

large area silicon drift detectors 1.5d spatial resolution anode drift Campana et al., 2011 Evangelista et al., 2012 The Gaussian-shaped cloud propagates along the drift direction, and reaches the read‐out anodes with a width σ which can be expressed as: The cloud can then be fitted using deriving Qtot, the anodic (X0) and the drift (σ) coordinates, the baseline (K)

IMAGING PERFORMANCE 32ch asic + 147 µm pitch sdd Anode pitch was optimized for imaging (taking into account constraints on power, ASIC size, bonding pad pitch, energy resolution, lower energy threshold…) Evangelista et al., 2012

Imaging performance of the ALICE SDD Alice + discrete fee set-up Imaging performance of the ALICE SDD (294 µm pitch) + 8ch discrete FEE Anode segmentation provides 1D photon absorption position with high spatial resolution (tens of µm) e- cloud width (σ) encodes information on drift distance → 2D (asymmetric) spatial resolution D → diffusion coeff. t → drift time kB → Boltzmann c. q → electron charge x → drift length E → electric field strength Campana et al., 2011

FEE requirements

Fee requirements

Pcb material

Pcb desing

Mechanical interface