Electron-optical assembly comprising electromagnetic shielding

A module comprising:

• an electron-optical device;
• and
• an electromagnetic shielding of a beam path through the module when in an electron-optical column for projecting a charged particle beam along the beam path towards a target, the electromagnetic shielding comprising:
• an up-beam section up-beam of the electron-optical device;
• and
• a down-beam section down-beam of the electron-optical device,
• wherein at least one of the up-beam and down-beam sections comprises an interface that extends in a direction radial to the beam path, the at least one of the up-beam and down-beam sections comprises a flange extending in a direction radial to the beam path,
• wherein the interface of the up-beam section forms an interface configured for use with up-beam elements of the column, wherein the interface of the up-beam interface is a facing surface,
• wherein the up-beam elements of the column comprise an upper beam section of the electromagnetic shielding, the interface of the up-beam section configured to be spaced away from the upper beam section by a gap when the module is present in an electron-optical column,
• wherein the gap is defined by facing surfaces of the up-beam and down-beam sections and extends away from the beam path.

A method for projecting a charged particle beam along a beam path towards a target, the method comprising:

• shielding the charged particle beam from an electromagnetic field external to the electromagnetic shielding;
• wherein the electromagnetic shielding comprises a plurality of sections extending along different positions along the beam path, each section surrounding the charged particle beam path,
• wherein the sections are separable and the sections are arranged such that a gap in the electromagnetic shielding is formed in a direction of the beam path, between at least two adjacent sections, the adjacent sections having facing surfaces that extend in a direction radial to the beam path and at least one of the facing surfaces comprises a flange extending in a direction radial to the beam path,
• wherein the gap is defined by the facing surfaces of the adjacent sections and extends away from the beam path.