Configurable charged-particle apparatus

A configurable charged-particle apparatus equipped with:

• a charged particle column comprising:
• a charged particle source for producing a beam of charged particles along an optical axis;
• and
• a magnetic immersion lens for focusing the beam of charged particles on a sample position, the magnetic immersion lens comprising a first lens pole, said first lens pole forming the part of the magnetic immersion lens farthest from the charged particle source;
• an excitation coil surrounding the first lens pole;
• at least a first stage on which a sample can be mounted, the first stage movable with respect to the optical axis;
• and
• one or more detectors for detecting radiation emanating from the sample in response to the beam of charged particles stimulating the sample;
• the immersion lens having a configurable magnetic circuit;
• wherein:
• the apparatus has at least a first configuration and a second configuration, the apparatus in the first configuration equipped to position the sample with respect to the optical axis while the sample is mounted on the first stage, the apparatus in the second configuration having a second lens pole mounted on the first stage, the second lens pole intersecting the optical axis, and the apparatus in the second configuration equipped with a second stage for mounting the sample thereon, the second stage equipped to position the sample between the first lens pole and the second lens pole, the second stage movable with respect to the optical axis,
• as a result of which the optical properties of the magnetic immersion lens differs in the first and the second configuration, and can in the second configuration be changed by positioning the second lens pole using the first stage, thus changing the magnetic circuit.