2020 Volume 19 Issue 3 Pages 71-79
Muon is an elementary particle that has electric charge and spin. When muon with positive charge (μ+) is implanted in a substance, it stops as muon or it acquires an electron in the substance and becomes muonium (Mu). If the substance has an unsaturated bond, muonium attacks it to generate a radical (muoniated radical). By monitoring the change in direction of muon/muonium spins from the polarized state, we can monitor the fluctuation of the magnetic field near the muon/muonium stopping sites. In the case of biomolecules, fluctuations in the magnetic field result from fluctuations in electron spins or atomic nuclear spins near the muon/muonium stopping sites. Moreover, since positive muons as it were light protons, fluctuations of muon spin themselves have the possibility of giving us the monitoring tool for proton transfer. The research aiming to establish the application of the muon spin rotation, relaxation and resonance (μSR) technique for bioscience at J-PARC/MLF will be introduced together with the pioneering studies.
