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.

An embodiment of the invention is a focusing magnet including a coil pair arranged on both sides of a path of a charged particle beam. The coil pair generates an effective magnetic field region in which a magnetic field is oriented in a direction (z-axis) perpendicular to a traveling direction (x-axis) of a charged particle beam. In an xy-plane, an incident charged particle beam deflected at a deflection angle with respect to the x-axis at a deflection point Q is deflected by the effective magnetic field region, and irradiates an isocenter at an irradiation angle with respect to the x-axis; an arbitrary point P2 on a boundary on an exit side of the effective magnetic field region is at an equal distance r.sub.1 from the isocenter; a point P1 on a boundary on an incident side of the effective magnetic field region and the point P2 are on a radius r.sub.2 and an arc of a central angle (+); and when a distance between the deflection point Q and the isocenter is L, a distance R between the deflection point Q and the point P1 satisfies a relational equation (4).

An embodiment of the invention is a focusing magnet including a coil pair arranged on both sides of a path of a charged particle beam. The coil pair generates an effective magnetic field region in which a magnetic field is oriented in a direction (z-axis) perpendicular to a traveling direction (x-axis) of a charged particle beam. In an xy-plane, an incident charged particle beam deflected at a deflection angle with respect to the x-axis at a deflection point Q is deflected by the effective magnetic field region, and irradiates an isocenter at an irradiation angle with respect to the x-axis; an arbitrary point P2 on a boundary on an exit side of the effective magnetic field region is at an equal distance r.sub.1 from the isocenter; a point P1 on a boundary on an incident side of the effective magnetic field region and the point P2 are on a radius r.sub.2 and an arc of a central angle (+); and when a distance between the deflection point Q and the isocenter is L, a distance R between the deflection point Q and the point P1 satisfies a relational equation (4).

An embodiment of the invention is a focusing magnet including a coil pair arranged on both sides of a path of a charged particle beam. The coil pair generates an effective magnetic field region in which a magnetic field is oriented in a direction (z-axis) perpendicular to a traveling direction (x-axis) of a charged particle beam. In an xy-plane, an incident charged particle beam deflected at a deflection angle with respect to the x-axis at a deflection point Q is deflected by the effective magnetic field region, and irradiates an isocenter at an irradiation angle with respect to the x-axis; an arbitrary point P2 on a boundary on an exit side of the effective magnetic field region is at an equal distance r.sub.1 from the isocenter; a point P1 on a boundary on an incident side of the effective magnetic field region and the point P2 are on a radius r.sub.2 and an arc of a central angle (+); and when a distance between the deflection point Q and the isocenter is L, a distance R between the deflection point Q and the point P1 satisfies a relational equation (4).

An embodiment of the invention is a focusing magnet including a coil pair arranged on both sides of a path of a charged particle beam. The coil pair generates an effective magnetic field region in which a magnetic field is oriented in a direction (z-axis) perpendicular to a traveling direction (x-axis) of a charged particle beam. In an xy-plane, an incident charged particle beam deflected at a deflection angle with respect to the x-axis at a deflection point Q is deflected by the effective magnetic field region, and irradiates an isocenter at an irradiation angle with respect to the x-axis; an arbitrary point P2 on a boundary on an exit side of the effective magnetic field region is at an equal distance r.sub.1 from the isocenter; a point P1 on a boundary on an incident side of the effective magnetic field region and the point P2 are on a radius r.sub.2 and an arc of a central angle (+); and when a distance between the deflection point Q and the isocenter is L, a distance R between the deflection point Q and the point P1 satisfies a relational equation (4).

A magnetic lens is disclosed, which includes: a magnetic yoke, an exciting coil and a power supply controlling system. The magnetic yoke is at outside of the exciting coil and surrounds the coil; the exciting coil is made up of litz wires; the power supply controlling system is arranged to supply power to the exciting coil and control the flow directions and magnitudes of the currents in the exciting coil. A method for controlling the magnetic lens is also disclosed.

With strength of an objective lens set to first strength, a first scanned image of a sample is produced. The strength of the objective lens is set to second strength. A rotation amount difference of a charged particle beam between the case where the strength is set to the first strength and the case where the strength is set to the second strength is specified. At the second strength, with a scanner controlled such that the rotation for canceling the rotation amount difference is supplied to the charged particle beam, a second scanned image of the sample is produced. Based on a relative positional relationship between the first and second scanned images, a deflector is controlled such that positions of the first and second scanned images coincide with each other.

Magnetic field strength of a converging lens is repeatedly and alternately changed between first strength and second strength. The information about a first aperture image in the case where the magnetic field strength is the first strength and the information about a second aperture image in the case where the magnetic field strength is the second strength are produced. A first movement instruction for the first and second aperture images is given based on the first information and the second information during repetitive changes of the magnetic field strength. Based on the first movement instruction, a first deflector is controlled. A second movement instruction for the first and second aperture images is given based on the first information and the second information during repetitive changes of the magnetic field strength. Based on the second movement instruction, a second deflector is controlled.

Embodiments herein are directed to a linear accelerator assembly for an ion implanter, wherein the linear accelerator includes a jacketed resonator coil. In some embodiments, a linear accelerator assembly may include a first fluid conduit and a coil resonator coupled to the first fluid conduit, wherein the coil resonator is operable to receive a first fluid via the first fluid conduit, wherein the coil resonator comprises a first coil conduit adjacent a second coil conduit, and wherein a first fluid channel defined by the first coil conduit is operable to receive the first fluid.

The object of the present invention provides a scanning transmission electron microscope with the ability to formed at least one diffraction pattern. The scanning electron microscope comprises an electron source, which is configured to provide primary electron beam, a condenser lens system, an objective electromagnetic system, a projection lens system and a detection system, in addition, the objective electromagnetic lens consists of an upper pole piece and a lower pole piece, wherein each pole piece comprises a pole piece face, which is a flat surface oriented towards a sample plane. A salient feature of the present invention is to form at least one diffraction pattern located in the distance from the lower pole piece face outside the pole piece gap, wherein the pole piece gap is the space between the upper pole piece face and the lower pole piece face.