The measurement for radiation tolerance of p-type Si sensor for ALICE FoCal detector

The Forward Calorimeter (FoCal) detector is scheduled for installing in the ALICE experiment for the LHC-Run4 upgrade (2029-2032). The FoCal consists of the FoCal-E (Electromagnetic Calorimeter) and the FoCal-H (Hadronic Calorimeter). The FoCal-E is a detector based on a Si sensor and tungsten to measure direct photons at forward rapidity. The radiation dose expected in Run4 is up to1.0×10¹⁴n_eq/cm², requiring high radiation tolerance. In the FoCal-E detector, a p-type sensor is considered to be used instead of the conventional n-type sensor. This is because p-type sensors are relatively easy to handle at high radiation doses, as there is no "type inversion", which happens for n-type sensors around 10¹²n_eq/cm². Furthermore, p-type sensors are more attractive due to their higher radiation tolerance up to 10¹⁶n_eq/cm². In this presentation, we summarize the I-V and C-V characteristics for p-type sensors for FoCal-E irradiated with about 10¹⁴n_eq/cm² at the RIKEN RANS (RIKEN Accelerator-driven compact Neutron Systems) in Japan and report on the results of radiation tolerance.