Systems and methods for synchronous operation of debris mitigation-or. Verschmutzungsabweisevorrichtungen

Systems and methods for synchronous operation of debris mitigation or Verschmutzungsabweisevorrichtungen (DMDs) emitted in a EUV radiation source, the EUV radiation and debris or dirt particles are disclosed. The methods include establishing a selected relative angular orientation between the first and second DMD provides a maximum portion of the transmission of EUV radiation between each first and second rotatable wings of the first and second DMD. The method also comprises rotating the first and second set of vanes to turn or to trap at least a portion of debris or dirt particles, while the selected relative angular orientation is substantially maintained. The systems employ DMD drive units, and measures an optical encoder disk in one of the DMD drive units and controls or controls the rotational speed of the rotatable DMD wing. Systems and methods for the optimal alignment of the DMDs are also disclosed.