The time dependence of the polarization of a stored proton beam was me
asured near an induced depolarizing resonance. The resonance was creat
ed by a magnetic field which oscillated along the beam axis. The dista
nce to the resonance was varied by changing the frequency of the oscil
lating field. The resonance was approached from either side and the ti
me dependence of the polarization was found to be symmetric with respe
ct to the resonance, and in agreement with an earlier measurement that
involved an intrinsic depolarizing resonance. (C) 1998 American Insti
tute of Physics. [S0034-6748(98)03009-3]