オーラルセッション
- 第3日 5月13日（水） 9:45～10:05 C会場（1101/02）
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3C-O12-0945 PDF
素粒子ミュオンを用いた非破壊同位体分析
Elemental isotopic ratios are measured in various research fields and provide useful information for absolute dating, origin of the material, geological and biological activities, etc. Here, we report a new isotopic analysis method without sample destruction using muon-induced characteristic X-rays (muonic X-rays).
Muons are elementary particles with charge equal to that of an electron and mass 207 times that of an electron. A muon can make a bound state with the nucleus, similar to electrons, and forms an atomic system called a muonic atom. A muon forms a much stronger bound state than that of electrons owing to its large mass, and high-energy muonic X-rays are emitted from muonic atom. Recently, non-destructive elemental analysis by muonic X-ray measurement (MIXE: Muon Induced X-ray Emission) have been developed and applied for various samples. Because muon atomic orbitals are strongly affected by nuclear charge distributions, different isotopes produce muonic X-rays with slightly different energies.
We demonstrated this method by conducting muon-beam irradiation experiments on two Pb plates with different isotopic ratios: natural isotopic composition and artificially enriched Pb. The isotopic ratios were determined from muonic X-ray intensities and the results were consistent with those obtained from mass spectrometry.