Patent attributes
A radiation system for controlling bursts of pulses of radiation comprises: an optical element; a controller; an actuator; and a sensor. The optical element is configured to interact with the pulses of radiation to control a characteristic of the pulses of radiation, the characteristic of the pulses of radiation being dependent on a configuration of the optical element. The controller is operable to generate a control signal. The actuator is configured to receive the control signal from the controller and to control a configuration of the optical element in dependence on the control signal. The sensor is operable to determine the characteristic of pulses having interacted with the optical element. The control signal for a given pulse in a given burst is dependent on the determined characteristic of a corresponding pulse from a previous burst.