Figure 31.

Principle of a μSR experiment. (a) Overview of the experimental setup. Spin polarized muons with spin S_μ antiparallel to the momentum p_μ are implanted in the sample placed between the forward (F) and the backward (B) positron detectors. A clock is started at the time the muon goes through the muon detector (M) and is stopped as soon as the decay positron is detected in the detectors F or B. Adapted with permission from ref (348). Copyright Swiss Physical Society. (b) The number of detected positrons N_F and N_B as a function of time for the forward and backward detector, respectively. Reproduced with permissions from ref (349). Copyright University of Zurich. (c) The so-called asymmetry (or μSR) signal is obtained by essentially building the difference between N_F and N_B (eq 2). All panels are adapted with permission under a Creative Common CC BY license from ref (350). Copyright 2019 MDPI.