Zero-energy muon cooling for a neutrino factory—present status and future directions

In order to realize an advanced concept of intense and high-quality neutrino beam, we propose to employ the method of the zero-energy cooling, namely, the generation of ultraslow μ+ by ionizing thermal muoniums emitted from the surface of a hot noble metal after stopping as much as possible a high-energy μ+ beam produced by the accelerator. A realistic yield estimation is given.