Experimental investigation of the impact of inter-strip incidence on the signal shape in Double Sided Silicon Strip Detectors for particle identification

We are currently developing a novel detection system, named FARCOS (Femtoscope Array for Correlation and Spectroscopy) and featuring high angular and energy resolution and able to reconstruct particle's momentum at high precision for different physical cases in multi-fragmentation nuclear physics experiments. Performing a Pulse Shape Analysis on signals coming from the ΔE stages -Double Sided Silicon Strip Detectors (DSSSDs) - we aim at identifying in charge and mass even particles stopping in the first detection layer. In the framework of the full characterization of the DSSSD response in terms of both the linearity of the amplitude response and of the efficiency and collection properties as a function of the point of incidence, we got evidences of significant alterations of the signals shape in case of particle injection in the inter-strip region. Such an effect, which depends also on the type and energy of the impinging particle, cannot be ascribed only to a mere charge division, especially in case of signals with “wrong” polarity, but to more complex phenomena - for instance charge induction on neighbor strips. In this work we present the results of the qualification campaign carried out exploiting the monochromatic pulsed proton beam facility available at LaBeC of INFN - Sezione di Firenze, focusing the attention on the aforementioned “inter-strip effect”. We interpreted the measurements also with the aid of dedicated 3D simulations performed with a custom semi-analytical code, which gives a better insight on the physics occurring in the device. The impact of the “inter-strip effect” on particle identification scatter plots is also discussed.