  The electromagnetic form factors of the proton and neutron encode information
on the spatial structure of their charge and magnetization distributions. While
measurements of the proton are relatively straightforward, the lack of a free
neutron target makes measurements of the neutron's electromagnetic structure
more challenging and more sensitive to experimental or model-dependent
uncertainties. Various experiments have attempted to extract the neutron form
factors from scattering from the neutron in deuterium, with different
techniques providing different, and sometimes large, systematic uncertainties.
We present results from a novel measurement of the neutron magnetic form factor
using quasielastic scattering from the mirror nuclei $^3$H and $^3$He, where
the nuclear effects are larger than for deuterium but expected to largely
cancel in the cross-section ratios. We extracted values of the neutron magnetic
form factor for low-to-modest momentum transfer, $0.6<Q^2<2.9$ GeV$^2$, where
existing measurements give inconsistent results. The precision and $Q^2$ range
of this data allow for a better understanding of the current world's data, and
suggest a path toward further improvement of our overall understanding of the
neutron's magnetic form factor.
