This invention provides a charged particle source, which comprises an emitter and means of generating a magnetic field distribution. The magnetic field distribution is minimum, about zero, or preferred zero at the tip of the emitter, and along the optical axis is maximum away from the tip immediately. In a preferred embodiment, the magnetic field distribution is provided by dual magnetic lens which provides an anti-symmetric magnetic field at the tip, such that magnetic field at the tip is zero.

This invention provides a charged particle source, which comprises an emitter and means fo generating a magnetic field distribution. The magnetic field distribution is minimum, about zero, or preferred zero at the tip of the emitter, and along the optical axis is maximum away from the tip immediately. In a preferred embodiment, the magnetic field distribution is provided by dual magnetic lens which provides an anti-symmetric magnetic field at the tip, such that magnetic field at the tip is zero.

This invention provides a charged particle source, which comprises an emitter and means of generating a magnetic field distribution. The magnetic field distribution is minimum, about zero, or preferred zero at the tip of the emitter, and along the optical axis is maximum away from the tip immediately. In a preferred embodiment, the magnetic field distribution is provided by dual magnetic lens which provides an anti-symmetric magnetic field at the tip, such that magnetic field at the tip is zero.

A multipole lens is provided which is for use in electron microscopy and which is simple in structure but capable of producing X- and Y-components of a quadrupole field and X- and Y-components of an octopole field. The multipole lens (100) comprises: first through twelfth polar elements (10-1 to 10-12); first through sixteenth coils (20-1 to 20-16); a first power supply (30-1) for supplying currents to the coils (20-1, 20-4, 20-9, 20-12); a second power supply (30-2) for supplying currents to the coils (20-3, 20-5, 20-11, 20-13); a third power supply (30-3) for supplying excitation currents to the coils (20-6, 20-8, 20-14, 20-16); and a fourth power supply (30-4) for supplying excitation currents to the coils (20-2, 20-7, 20-10, 20-15). The coils (20-1, 20-3, 20-6, 20-7, 20-9, 20-11, 20-14, 20-15) produce magnetic fields in a first direction. The coils (20-2, 20-4, 20-5, 20-8, 20-10, 20-12, 20-13, 20-16) produce magnetic fields in a direction opposite to the first direction.

A particle beam treatment system having a beam generation unit for generating a beam of charged particles, in particular ions, preferably protons, and having a beam guidance system. The generic beam guidance system takes up less space but can provide comparable or even improved beam properties because, in part, the beam guidance system seen in the direction of the beam of charged particles and behind the beam generation unit has at least one solenoid magnet as a beam shaping unit, and the at least one solenoid magnet of the beam guidance system is a superconducting solenoid magnet.

A particle beam system includes: a multi-beam particle source configured to generate a multiplicity of particle beams; an imaging optical unit configured to image an object plane in particle-optical fashion into an image plane and direct the multiplicity of particle beams on the image plane; and a field generating arrangement configured to generate electric and/or magnetic deflection fields of adjustable strength in regions close to the object plane. The particle beams are deflected in operation by the deflection fields through deflection angles that depend on the strength of the deflection fields.

A system for protecting a sensor, the system includes a controller and an electron shielding unit that is located upstream to the sensor and is configured to: (i) enable, under a control of the controller, electrons emitted from the region to reach the sensor during an evaluation iteration in which a region of the sample is illuminated with an electron beam, and (ii) shield, under the control of the controller, the sensor from electrons emitted from the region during a discharging iteration in which the region is illuminated with a laser beam, wherein a timing of the discharging iteration is based on one or more timing constraints associated with the evaluation iteration.

A scanning electron microscope having an electron column positioned to direct an electron beam onto a sample the electron column having a vacuum enclosure; an electron source; and an electromagnetic objective lens positioned within the vacuum enclosure, the electromagnetic objective lens including a housing having an entry aperture at top surface thereof and an exit aperture at bottom thereof; an electromagnetic coil radially positioned within the housing; a light objective positioned within the housing and comprising a concave minor having a first axial aperture and a convex minor having a second axial aperture; an electron beam deflector positioned within the housing and comprising a first set of deflectors and a second set of deflectors positioned below the first set of deflectors, wherein the second set of deflectors is positioned below the first axial aperture and the first set of deflectors is positioned above the second set of deflectors.

A particle beam system includes: a multi-beam particle source configured to generate a multiplicity of particle beams; an imaging optical unit configured to image an object plane in particle-optical fashion into an image plane and direct the multiplicity of particle beams on the image plane; and a field generating arrangement configured to generate electric and/or magnetic deflection fields of adjustable strength in regions close to the object plane. The particle beams are deflected in operation by the deflection fields through deflection angles that depend on the strength of the deflection fields.

A multiple particle beam system comprises: a magnetic lens through which a plurality of individual charged particle beams pass; and a controller configured to control, such as dynamically control, the magnetic lens. The magnetic lens comprises a coil, a winding body and a pole shoe. The coil is arranged around the winding body and the winding body is a hollow body through which the plurality of individual particle beams pass. The coil, together with the winding body, is arranged within the pole shoe. The pole shoe has an opening through which a magnetic field created by the magnetic lens emerges from the pole shoe and interacts with the plurality of individual particle beams to obtain a lens effect. The winding body is electrically conductive and has an interruption, by which the electrical conductivity of the winding body is interrupted in the circumferential direction around the particle-optical axis.