  We propose to use slow muons facilities combined with cyclotron radiation
detection for precision test of the weak interaction in the muon decays. Slow
positive muon bunches are first injected into a cylindrical superconducting
vacuum chamber with uniform strong axial magnetic fields to radially confine
the muons. The positrons resulting from muon decays can be detected by their
cyclotron radiation, which can be transported to low-noise electronic devices
through waveguides coupled to the chamber. The decay positron's energy can be
precisely measured down to eV level in the low energy region, which is
sensitive to new physics effects such as Majorana neutrinos and new structures
of weak interactions.
