A control device for a magnetic resonance system activates the coils of a
transmission array and a gradient magnet system of the magnetic resonance
system by causing an excitation pulse to be supplied to each coil. A
magnetization that exhibits a first actual inhomogeneity thereby is
generated in an excitation volume of the magnetic resonance system. The
control device determines the excitation pulse for each coil using a
start pulse and a maximum allowable inhomogeneity. The respective start
pulse has a total time duration. When the control device activates the
coils of the transmission array and of the gradient magnet system
corresponding to the start pulse, a magnetization that exhibits a second
actual inhomogeneity that is smaller than the maximum permissible
inhomogeneity is generated in the excitation volume. The control device
determines an intermediate point of the start pulse so that the
respective start pulse is divided into a first pulse part and a second
pulse part that is complementary to the first pulse part. The first pulse
part corresponds to a respective low-energy portion of the start pulse,
the second pulse part with a high-energy portion of the respective start
pulse. The control device temporally extends the second pulse part and
correspondingly compresses the second pulse part in terms of amplitude.
The temporally extended and amplitude-compressed pulse part is used as
the excitation pulse. The control device determines the intermediate
point such that the first inhomogeneity is still smaller than the maximum
allowable inhomogeneity.