Charge-Reversal-Based Extraction of Muonic Ions

摘要: Negative muon capture in matter is accompanied by Auger electron emission and
the formation of positively charged muonic ions. This charge reversal provides
a possibility for electromagnetic extraction of the products of muon capture.
Here we propose a charge-reversal-based extraction scheme for muonic ions, in
which negative muons are moderated and confined in a dilute gas environment
before conversion, and the resulting muonic ions are subsequently accelerated
and extracted by electrostatic fields. The feasibility of the concept is
investigated through order-of-magnitude estimates of the competing processes,
including muon moderation, muonic-ion formation, charge exchange, and
acceleration in the gas medium. A magnetic-electrostatic deceleration scheme is
proposed to reduce the transverse phase space of practical low-energy muon
beams while retaining controlled longitudinal motion, and is directly matched
to the electrostatic capture region. The analysis indicates that muonic-ion
formation and extraction within the muon lifetime are not excluded by
fundamental timescale constraints, although the quantitative efficiency remains
uncertain because several relevant low-energy cross sections and charge-state
populations are poorly constrained experimentally.