Phase space compression of muon beams

A phase space compression technique applicable to short-lived particles is proposed. Its specific feature is that it treats each single particle separately by measuring its phase space via position sensitive particle detectors and steers it via pulsed electromagnetic deflection. By applying the method to muons, very high quality low energy beams can be obtained. A specific design is presented that should allow to achieve a 50 keV muon beam with 0.1 π mm mrad transverse emittance and 104s-1 intensity. These muons can be further decelerated to ultralow energies so that for example a 50 eV beam with 3 π mm mrad and Δp/p=10-3 is obtained. The overall phase space compression compared to the entrance beam exceeds 1015. With such beams, stopping of muons in atomic beams or on the first atomic layer of a solid can be envisioned. A short list of possible physics applications is given. (orig.)