Description
μSR is a spectroscopy using a spin-polarized muon beam. It is a method to observe the muon spin rotation, relaxation and resonance by using the detection of positrons emitted asymmetrically to the muon spin axis, and is widely used as one of the physical property methods to search for magnetic fields inside materials. However, the conventional μSR can only measure physical properties of the entire sample because it uses detectors without position sensitivity. Therefore, we have developed a new method called muon spin imaging using position-sensitive detectors. This method can determine the muon stop position in the sample by tracking the muon and positron trajectories, and enables μSR measurements in a small area of the sample. Then, by analyzing the μSR spectra for each sample position, 3D imaging of the sample with various μSR parameters becomes possible. In this study, 2D images of a sample of a known material combination were produced using a surface muon beam with uniform energy, and the position resolution of the images was evaluated. The experiment was performed at the TRIUMF in September 2024, using a drift chamber and a fiber tracker for muon and positron position measurements, respectively. As a result, the distribution of the Al + Al2O3 sample was reproduced. Translated with DeepL.com (free version)＊The author is grateful to F-REI (JPFR24040302) for the support of travel expenses.
