thereby estimating the purely magnetic cross section at T = 2 K. The scattering in Fig. -b displays a weak peak at ∼6 meV and strong scattering at low energies below ∼3 meV. This is further displayed in Fig. which plots the momentum integrated intensity as a function of energy for the two experimental configurations. For comparison, the data are normalized to agree at low energy transfers. The dashed line is discussed below in terms of a parameterization of the microscopic magnetic Hamiltonian.