  The transfer of neutrons onto 24Ne has been measured using a reaccelerated
radioactive beam of 24Ne to study the (d,p) reaction in inverse kinematics. The
unusual raising of the first 3/2+ level in 25Ne and its significance in terms
of the migration of the neutron magic number from N=20 to N=16 is put on a firm
footing by confirmation of this state's identity. The raised 3/2+ level is
observed simultaneously with the intruder negative parity 7/2- and 3/2- levels,
providing evidence for the reduction in the N=20 gap. The coincident gamma-ray
decays allowed the assignment of spins as well as the transferred orbital
angular momentum. The excitation energy of the 3/2+ state shows that the
established USD shell model breaks down well within the sd model space and
requires a revised treatment of the proton-neutron monopole interaction.
