We have performed elastic and inelastic neutron-scattering measurement
s on the heavy-fermion superconductor URu2Si2 in a magnetic field of 1
2 T along the c-axis of the tetragonal crystal structure. The small or
dered moment and the energy gap in the magnetic excitation spectrum sh
aw a comparable transition temperature in a magnetic field of 12 T. Th
is is in disagreement with recent predictions of a decoupling of the o
rdered moment and the energy gap in high magnetic fields.