¹I-Huan Chiu,²Kentaro Terada,³Takahito Osawa,⁴Changkun Park,⁵Soshi Takeshita,⁵Yasuhiro Miyake,¹Kazuhiko Ninomiya
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14059]
¹Institute Radiation Sciences, Osaka University, Osaka, Japan
²Graduate School of Science, Osaka University, Osaka, Japan
³Nuclear Science Research Institute, Japan Atomic Energy Agency, Ibaraki, Japan
⁴Korea Polar Research Institute, Incheon, Republic of Korea
⁵High Energy Accelerator Research Organization (KEK), Ibaraki, Japan
Published by arrangement with John Wiley & Sons

We report the result of a non-destructive elemental analysis of lunar meteorites using a negative muon beam at J-PARC. An experimental system of six Ge semiconductor detectors and a newly designed He analysis chamber (to enable quantitative analysis of Al) was used to provide a high signal-to-noise ratio for the detection of major elements from lunar rocks (Mg, Si, Fe, O, Ca, and Al). We performed a Monte Carlo simulation to determine the chemical compositions at two sides and the center of a sample (at depths of 0.33 and 0.96 mm below the sample surface, respectively) of the lunar meteorite DEW 12007. These results indicate that the three interior regions of DEW 12007 are likely to be 55.8:44.2, 51.4:48.6, and 54.4:45.6 wt% mixtures of anorthositic and basaltic clasts, respectively. This study is the first quantitative analysis of a heterogeneous meteorite interior using a negative muon beam. As elemental analysis using a muon beam is non-destructive and highly sensitive to light elements, including C, N, and O, the protocols established in this study are applicable to initial characterization of returned samples from the South Pole of the Moon.