We report a measurement of the asymmetry in spin-dependent quasielastic scattering of longitudinally polarized electrons from a polarized ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ target. The neutron magnetic form factor ${\mathit{G}}_{\mathit{M}}^{\mathit{n}}$ has been extracted from the measured asymmetry based on recent PWIA calculations using spin-dependent spectral functions. Our determination of ${\mathit{G}}_{\mathit{M}}^{\mathit{n}}$ at ${\mathit{Q}}^2$=0.19 (GeV/c${)}^2$ agrees with the dipole parametrization. This experiment represents the first measurement of the neutron magnetic form factor using spin-dependent electron scattering.

DOI:https://doi.org/10.1103/PhysRevC.50.R546