A lithographic arrangement allows for controlling radiation characteristics. An illumination system provides a beam of radiation from radiation provided by a radiation source. The radiation source includes an array of individually controllable elements, each individually controllable element being capable of emitting radiation. A support structure supports a patterning device. The patterning device imparts the radiation beam with a pattern. A projection system projects the patterned radiation beam onto a target portion of a substrate held by a substrate table. A radiation peak intensity detection apparatus detects a peak in the intensity of an emission spectrum of one or more of the individually controllable elements of the radiation source.