Patent ID: 8828506

Claim:
A method to produce plasma by photon radiation from a target body comprising target material having an ablation threshold and an absorbance of said photon radiation, comprising: selecting an ablation area on the target body for the generation of plasma from a spot on said ablation area, selecting a radiation geometry for said photon radiation, to focus said photon radiation onto the spot on said target body, controlling ablation of said target body by: controlling an ablation depth in said target body by adjusting a spot size of said photon radiation on said ablation area or by scaling the power of said photon radiation for said spot so that the photon radiation fluence exceeds the ablation threshold on said target body in the spot to a selected ablation depth defined by the absorbance of the target material in said spot, and scaling a spot size and/or radiation power of said photon radiation so that the ratio of the spot size dimension to said ablation depth is adjusted to a constant value for said target area for the duration of the scanning with said radiation, directing said photon radiation along a radiation path from a radiation source to said spot on the target body via a turbine scanner, in which reflective surfaces are faces of a polygon that is arranged to rotate around a rotation axis, and generating said plasma by scanning said photon radiation so that said spot moves along an ablation path on said ablation area.