Measurement of the neutron magnetic form factor from inclusive quasielastic scattering of polarized electrons from polarized [sup 3]He

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