Cosmic ray muon imaging for the internal structure of the Jiuyan Tower of the Great Wall

Abstract

This study utilizes cosmic ray muon transmission imaging to explore the internal structure of the Jiuyan Enemy Tower in Beijing. By measuring cosmic ray muon flux variations from two external observation points and integrating these data with a 3D model derived from laser scanning, we mapped the tower’s internal density distribution, showing strong consistency with predicted models. Additionally, four internal observation points revealed low-density areas on the middle platform, explaining previous leakage issues. Cosmic ray muon imaging, with its non-invasive and density-sensitive capabilities, provides a comprehensive “physical examination” of the 500-year-old Jiuyan Tower. This study highlights the potential of muon imaging in the preservation and exploration of cultural relics.