Patent ID: 9437408
Filing Date: 2016-09-06
CPC Classification: G01N,H01J

Claim Text:
1. A method for determining at least one parameter related to charged particles emitted from a particle emitting sample, comprising the steps of: forming a particle beam of said charged particles and transporting the particles between said particle emitting sample and an entrance of a measurement region by means of a lens system operated in angular mode and having a substantially straight optical axis, the entrance being a slit; deflecting the particle beam in at least a first coordinate direction perpendicular to the optical axis of the lens system before entrance of the particle beam into the measurement region, detecting the positions of said charged particles in said measurement region, the positions being indicative of said at least one parameter, wherein detecting the positions of the charged particles involves detection of the positions in two dimensions, one of which is used to detect the energies of the particles and one of which is used to detect the start directions of the particles in the direction along the slit, and deflecting the particle beam in the same at least first coordinate direction at least a second time before entrance of the particle beam into the measurement region and controlling the deflections of the particle beam such that a predetermined part of the angular distribution of the particles forming the particle beam passes the entrance of the measurement region to detect the start directions of the particles in the direction across the slit so that the detection of the start directions is performed in a two-dimensional manner with respect to a plane of the slit.