When an emission current is changed, a decrease in brightness of an electron beam is prevented. An electron gun includes a cathode that emits thermoelectrons, a Wehnelt electrode that focuses the thermoelectrons, a control electrode that extracts the thermoelectrons from a distal end of said cathode, an anode that accelerates the thermoelectrons and irradiates a powder with the thermoelectrons as an electron beam, and an optimum condition collection controller that changes at least one of a bias voltage to be applied to the Wehnelt electrode and a control electrode voltage to be applied to the control electrode, and decides a combination of the bias voltage and the control electrode voltage at which the brightness of the electron beam reaches a peak.

A system for manufacturing of three dimensional objects by layered deposition is provided. The system includes a base substrate for formation of three dimensional objects placed on a supporting plate; a functional assembly comprising a gas-discharge electron beam gun, a feedstock guide, a cold annular cathode and two annular anode electrodes, a high voltage power supply of the gas-discharge electron beam gun, a system of precise positioning of the supporting plate with the base substrate), a vacuum tight operation chamber, a vacuum subsystem for creating of necessary vacuum inside said operating chamber, a control system and a magnetic lens. The lens is placed on the underside of the gas-discharge electron beam gun coaxially with it and with the feedstock guide, providing the possibility of transformation of a primary hollow electron beam to the shape of a hollow inverted cone after leaving the discharge chamber of the gas-discharge electron beam gun.

The method is for automatic astigmatism correction of a lens system. A first image is provided that is not in focus at a first stigmator setting of a set of lenses. A calculating device calculates a corresponding first Fourier spectrum image. A distribution and direction of pixels of the Fourier spectrum image are determined by calculating a first vector and a second vector. The first vector is compared with the second vector. The lens system is changed from a first stigmator setting to a second stigmator setting to provide a second image. A corresponding Fourier spectrum image is calculated. The distribution and direction of pixels of the second Fourier spectrum image is determined by calculating a third vector and a fourth vector. The third vector is compared to the fourth vector. The image that has the lowest vector ratio is selected.

When an emission current is changed, a decrease in brightness of an electron beam is prevented. An electron gun includes a cathode that emits thermoelectrons, a Wehnelt electrode that focuses the thermoelectrons, a control electrode that extracts the thermoelectrons from a distal end of said cathode, an anode that accelerates the thermoelectrons and irradiates a powder with the thermoelectrons as an electron beam, and an optimum condition collection controller that changes at least one of a bias voltage to be applied to the Wehnelt electrode and a control electrode voltage to be applied to the control electrode, and decides a combination of the bias voltage and the control electrode voltage at which the brightness of the electron beam reaches a peak.

Provided is a charged-particle-beam device capable of simultaneously cancelling out a plurality of aberrations caused by non-uniform distribution of the opening angle and energy of a charged particle beam. The charged-particle-beam device is provided with an aberration generation lens for generating an aberration due to the charged particle beam passing off-axis, and a corrective lens for causing the trajectory of the charged particle beam to converge on the main surface of an objective lens irrespective of the energy of the charged particle beam. The main surface of the corrective lens is disposed at a crossover position at which a plurality of charged particle beams having differing opening angles converge after passing through the aberration generation lens.

Provided is a charged-particle-beam device capable of simultaneously cancelling out a plurality of aberrations caused by non-uniform distribution of the opening angle and energy of a charged particle beam. The charged-particle-beam device is provided with an aberration generation lens for generating an aberration due to the charged particle beam passing off-axis, and a corrective lens for causing the trajectory of the charged particle beam to converge on the main surface of an objective lens irrespective of the energy of the charged particle beam. The main surface of the corrective lens is disposed at a crossover position at which a plurality of charged particle beams having differing opening angles converge after passing through the aberration generation lens.

Techniques for adjusting the shape of an ion beam are described. Characteristics of a desired beam shape may be defined. The ion beam generator may include beam shaping elements associated with tunable parameters that can be set in combination with each other. A search space for the possible combinations is defined. A set of exploratory points in the search space are measured and used to interpolate a large number of interpolated points based on a regression model. Interpolated points that are associated with low confidence values may be measured. Based on the measured and interpolated points, clusters of tunable parameter combinations may be identified for evaluation. The clusters are evaluated for stability and sensitivity, and one of the clusters is selected based on the evaluation. The ion beam generator may be configured based on the selected cluster.

Techniques for adjusting the shape of an ion beam are described. Characteristics of a desired beam shape may be defined. The ion beam generator may include beam shaping elements associated with tunable parameters that can be set in combination with each other. A search space for the possible combinations is defined. A set of exploratory points in the search space are measured and used to interpolate a large number of interpolated points based on a regression model. Interpolated points that are associated with low confidence values may be measured. Based on the measured and interpolated points, clusters of tunable parameter combinations may be identified for evaluation. The clusters are evaluated for stability and sensitivity, and one of the clusters is selected based on the evaluation. The ion beam generator may be configured based on the selected cluster.