Radiation Tolerance Characterisation of an Indigenously Developed p-type Silicon Pad Sensor for Forward Calorimetry Applications

Abstract

We report on the radiation tolerance characterisation of a p-type silicon pad sensor indigenously designed by BARC-VECC and fabricated at Bharat Electronics Limited (BEL), India -- representing a significant step toward establishing a domestic silicon sensor manufacturing capability for high-energy physics applications. Single-pad test structures were irradiated with neutrons over a range of fluences from $\sim10^{7}$ to $\sim2.5\times10^{14}$~1~MeV~$n_{\mathrm{eq}}$/cm$^{2}$, spanning the operational regime relevant to forward calorimetry in high-luminosity heavy-ion collider experiments. Post-irradiation performance was characterised through systematic measurement of leakage current evolution and calorimetric response as functions of accumulated neutron fluence. A single-exponential annealing model is introduced to describe the time dependence of leakage current within the observation window, and the current-related damage constant $\alpha$ is extracted and compared with the RD48 reference value. The results demonstrate that the sensors survive the target fluence with measurable but recoverable degradation, validating the fabrication process and providing a baseline for future qualification of this indigenous sensor production chain.