Particle beam system for adjusting the current of individual particle beams

A multi-beam particle microscope, comprising:

• a particle source configured to generate a beam of charged particles;
• a first multi-lens array comprising a first multiplicity of individually adjustable and focusing particle lenses in a beam path of the charged particles so that at least some of the charged particles pass through openings in the first multi-lens array in the form of a plurality of individual charged particle beams;
• a first multi-aperture plate comprising a multiplicity of second openings in the beam path of the charged particles downstream of the first multi-lens array so that:
• i) some of the charged particles which pass the first multi-lens array impinge on the first multi-aperture plate and are absorbed by the first multi-aperture plate;
• and ii) some of the charged particles which pass the first multi-lens array also pass through the openings in the first multi-aperture plate;
• and
• a controller configured to supply an individually adjustable voltage to the particle lenses of the first multi-lens array to adjust the focusing of an associated particle lens for each individual charged particle beam, thereby adjusting, for each individual charged particle beam:
• i) a beam diameter of the individual charged particle beam when it impinges on the first multi-aperture plate to adjust ii) a number of charged particles in the individual charged particle beam that is blocked by the first multi-aperture plate;
• iii) a number of charged particles in the individual charged particle beam that pass through the respective second opening in the first multi-aperture plate;
• and iv) a current of the individual charged particle beam downstream of the first multi-aperture plate,
• wherein the multi-beam particle microscope is configured so that the plurality of individual charged particle beams is incident an object plane of the multi-beam particle microscope.