Multi-beam charged particle system

A multi-beam charged particle system, comprising:

• a particle source configured to generate charged particles;
• a multi-aperture plate module comprising a multi-aperture plate;
• an electron detector;
• an object stage;
• a vacuum enclosure;
• and
• a pump system,
• wherein:
• the vacuum enclosure comprises a plurality of vacuum spaces connected by tubes;
• the plurality of vacuum spaces comprises first, second and third vacuum spaces;
• the first vacuum space houses the particle source;
• the second vacuum space houses the object stage;
• the third vacuum space houses the electron detector;
• the vacuum system is configured to evacuate each of the first, second and third vacuum spaces;
• and
• the multi-beam charged particle system is configured so that, during use of the multi-beam charged article system when an object is mounted on the object stage, the multi-aperture plate generates a plurality of particle beams from charged particles traversing apertures of the multi-aperture plate and the plurality of particle beams enter the second vacuum space to be incident on the object.