Characteristics of silicon strip sensor irradiated up to a proton fluence of 10¹⁷n_eq∕cm²

Silicon semiconductor detector technology has been adopted in experiments using the high-luminosity upgrade of the CERN Large Hadron Collider (HL-LHC), to perform precision tracking in the inner region surrounding the collision point, where the traversing particle fluence reaches 1×10¹⁶ 1-MeV n_eq∕cm². In the future, hadron colliders should provide even higher luminosities for rare physics searches, with detectors that exhibit even better radiation hardness. Fabricated by Hamamatsu Photonics, n⁺-in-p microstrip detectors developed for the HL-LHC were irradiated with 70 MeV protons up to a fluence of 10¹⁷n_eq∕cm², and the changes in the characteristics were evaluated to estimate the performance and possible improvements in the design of the silicon detector for future experiments. The characterization was conducted based on the methods developed for the characterization of the ATLAS Inner Tracker strip sensors; the charge collection measured with penetrating ⁹⁰Sr β-rays, the interstrip capacitance and aluminum strip resistance, the poly-silicon bias resistance, the implant strip resistance, and the punch-through protection.