Field Ionization of Strongly Magnetized Rydberg Positronium: A New Physical Mechanism for Positron Accumulation

Magnetized Rydberg positronium forms when an energetic positron ( $e^{+}$) slows within a tungsten crystal and picks up an electron ( $e^{-}$) as it emerges in a strong magnetic field. The signature is equal numbers of $e^{+}$ and $e^{-}$ when a weak electric field is applied, either of which can be accumulated and counted. The new $e^{+}$ accumulation technique is simple, robust, and much more efficient than any other demonstrated to be compatible with a cryogenic vacuum. Possible applications include the study of cold single component plasmas of $e^{+}$ and the formation of cold antihydrogen.