Diffusion of muonic deuterium inD2gas

Diffusion of muonic deuterium (μd) atomd in ${\mathrm{D}}_2$ at 300 K was studied at pressures of 0.1–10 bars by measuring the distributions of time intervals between entry of negative muons into the gas and detection of photons emitted upon the arrival of μd atoms at foils spaced along the muon beam axis. Results indicate an approximately Maxwellian velocity distribution with a mean energy of 1.8±0.1 eV for the μd atoms, and μd scattering cross sections in agreement with theory.