NCU researchers use muon imaging to peer inside Taiwan's mountains

Taipei, Jan. 12 (CNA) Researchers at National Central University (NCU) on Monday said they completed Taiwan's first outdoor experiment using muons to examine the internal density structure of mountains, a method likened to taking an X-ray of the Earth.

The technique could be applied in geothermal development and geological carbon dioxide storage, the university said as it shared results from the team's research at a press conference in Taipei on Monday.

Led by professors Kuo Chia-ming (郭家銘) and Chen Chien-chih (陳建志), the project has been selected for grant funding under the Shackleton Program, the university said.

The team said they used a scintillator and a silicon photomultiplier to measure muons, a subatomic particle similar to electrons, that are produced when cosmic rays interact with the Earth's atmosphere.

Muons possess a strong penetrating power, according to Kuo, and were detected as they passed through hundreds of meters of rock to analyze the mountain's internal structure.

This approach created a compact, low-power and stable sensing system suitable for long-term outdoor use, the team said.

Taiwan's first outdoor muon detection experiment was completed above the Shimen Reservoir Siltation Control Tunnel in Taoyuan in early 2025, according to NCU.

The researchers said they also targeted the Tatun Volcano Group near Taipei in late 2025.

Chen said Taiwan's complex geology, steep terrain and challenges such as volcanoes, landslides, geothermal resources and underground engineering make it a suitable testing ground for muon imaging technology.

Chen also said the technology could also provide scientific support for Taiwan's transition to net zero.