The disclosed embodiments relate to a charged particle source module for generating and emitting a charged particle beam, such as an electron beam, comprising: a frame including a first frame part, a second frame part, and one or more rigid support members which are arranged between said first frame part and said second frame part; a charged particle source arrangement for generating a charged particle beam, such as an electron beam, wherein said charged particle source arrangement, such as an electron source, is arranged at said second frame part; and a power connecting assembly arranged at said first frame part, wherein said charged particle source arrangement is electrically connected to said connecting assembly via electrical wiring.

An electron gun may include a cathode with an emitting surface configured to emit electrons. The cathode may include a through hole that goes through the emitting surface and is configured to allow back-streaming electrons of the emitted electrons to pass through. The electron gun may also include an anode configured to attract the emitted electrons from the cathode to the anode and focus the emitted electrons into an electron beam. The electron gun may also include a grid structure configured to facilitate the focusing of the emitted electrons, the grid structure being positioned corresponding to the through hole.

A particle beam device has a particle source, an extraction stop, an anode stop and a beam tube. A driver system of the particle beam device is configured to apply an electrical excitation stop potential to the extraction stop, to apply an electrical anode stop potential, able to be set in a variable manner, to the anode stop and to apply an electrical beam tube potential to the beam tube. A controller of the particle beam device is configured to control the driver system such that a voltage between the extraction stop and the anode stop is able to be set in a variable manner, as a result of which a current strength of the particle beam passing through the aperture of the anode stop is able to be set in a variable manner.

A method is provided for forming a three-dimensional article through successively depositing individual layers of powder material that are fused together so as to form the article, the method comprising the steps of: providing at least one electron beam source emitting an electron beam for at least one of heating or fusing the powder material, where the electron beam source comprises a cathode, an anode, and a Wehnelt cup between the cathode and anode; providing a guard ring between the Wehnelt cup and the anode and in close proximity to the Wehnelt cup, where the guard ring is having an aperture which is larger than an aperture of the Wehnelt cup; protecting the cathode and/or the Wehnelt cup against vacuum arc discharge energy currents when forming the three-dimensional article by providing the guard ring with a higher negative potential than the Wehnelt cup and cathode.

A permanent-magnet particle beam apparatus and method incorporating a non-magnetic portion for tunability are provided. The permanent-magnet particle beam apparatus includes a particle beam emitter that emits a charged particle beam, and includes a set of permanent magnets forming a magnetic field for controlling condensing of the charged particle beam. The permanent-magnet particle beam apparatus further includes a non-magnetic electrical conductor component situated with the set of permanent magnets to control a kinetic energy of the charged particle beam moving through the magnetic field.

An object is to provide an electron beam applicator suitable for an electron gun having a photocathode and an electron beam emission method in the electron beam applicator. The object can be achieved by an electron beam applicator including: an electron gun section; a main body section; and a control unit. The electron gun section includes a light source, a photocathode that emits an electron beam in response to receiving excitation light emitted from the light source, and an anode. The main body section includes an objective lens that converges an electron beam emitted from the electron gun section. The control unit controls at least convergence power of the objective lens in accordance with a size of an electron beam emitted from the photocathode.

The disclosed embodiments relate to a charged particle source module for generating and emitting a charged particle beam, such as an electron beam, comprising: a frame including a first frame part, a second frame part, and one or more rigid support members which are arranged between said first frame part and said second frame part; a charged particle source arrangement for generating a charged particle beam, such as an electron beam, wherein said charged particle source arrangement, such as an electron source, is arranged at said second frame part; and a power connecting assembly arranged at said first frame part, wherein said charged particle source arrangement is electrically connected to said connecting assembly via electrical wiring.

Electron gun systems with a particular inner width dimension, sweep electrodes, or a combination of a particular inner width dimension and sweep electrodes are disclosed. The inner width dimension may be less than twice a value of a Larmor radius of secondary electrons in a channel downstream of a beam limiting aperture, and a Larmor time for the secondary electrons may be greater than 1 ns. The sweep electrode can generates an electric field in a drift region, which can increase kinetic energy of secondary electrons in the channel.

An electron gun and an apparatus incorporating the electron gun. The electron gun includes an electron emission element, an electrode, a control element, and a control circuit. The electron emission element is arranged to be activated to emit electron beam. The electrode is arranged to be electrically connected with a power supply to accelerate the emitted electron beam. The control element may be arranged between the electron emission element and the electrode. The control element is arranged to be electrically connected with the power supply to provide an electric field to control emission of electron beams from the electron emission element. The control circuit is electrically connected with the control element for changing the electric field provided by the control element.

An electron gun comprising a cathode having an electron emitting surface and whose planar shape is circular; a heater; an anode being arranged to oppose the cathode; and a heat resistant member. The anode applies a positive potential relative to the cathode to extract electrons in a predetermined direction. The cathode has, in a central portion thereof, a through hole along a central axis of the cathode. The heat resistant member has a first portion to close the through hole and a second portion being positioned between the cathode and the heater.