Patent ID: 6455848
Filing Date: 2002-09-24
Classification: H01J

Abstract:
A particle-optical apparatus which includes:a particle source for producing a primary beam of electrically charged particles which travel along an optical axis (4) of the apparatus, a sample holder (20) for a sample (14) to be irradiated by the primary beam, a focusing device (8) for forming a focus of the primary beam having a plurality of energy levels in the vicinity of the sample holder (20), at least two Wien filters (34, 36) which are arranged between the particle source and the focusing device (8), wherein means (58, 66, 68) for generating a quadrupole field, said means being arranged at an area of each of the respective said at least two Wien filters so that at least a part of each respective quadrupole field coincides with a field of the associated Wien filter.