A 4G magnetron is disclosed. The magnetron may include an anode, having a cylindrical member and anode vanes disposed within the cylindrical member which define resonant cavities therebetween, and a dispenser cathode, suitable for heating and located coaxially within said anode. The magnetron may operate in a temperature range of about 850-1050 C. The magnetron may include conductive cooling. The magnetron may comprise inventive anode and cathode structures. A method for preparing a plurality of magnetron tubes substantially simultaneously is further provided.

A 4G magnetron is disclosed. The magnetron may include an anode, having a cylindrical member and anode vanes disposed within the cylindrical member which define resonant cavities therebetween, and a dispenser cathode, suitable for heating and located coaxially within said anode. The magnetron may operate in a temperature range of about 850-1050 C. The magnetron may include conductive cooling. The magnetron may comprise inventive anode and cathode structures. A method for preparing a plurality of magnetron tubes substantially simultaneously is further provided.

A filament assembly can include: a button having a planar emitter region with one or more apertures extending from an emission surface of the planar emitter region to an internal surface opposite of the emission surface; an inlet electrical lead coupled to the button at a first side; an outlet electrical lead coupled to the button at a second side opposite of the first side; and a low work function object positioned adjacent to the internal surface of the planar emitter region and retained to the button. The planar emitter region can include a plurality of apertures. The low work function object can include a porous ceramic material having the barium, and may have a polished external surface. An electron gun can include the filament assembly. An additive manufacturing system can include the electron gun having the filament assembly.

A filament assembly can include: a button having a planar emitter region with one or more apertures extending from an emission surface of the planar emitter region to an internal surface opposite of the emission surface; an inlet electrical lead coupled to the button at a first side; an outlet electrical lead coupled to the button at a second side opposite of the first side; and a low work function object positioned adjacent to the internal surface of the planar emitter region and retained to the button. The planar emitter region can include a plurality of apertures. The low work function object can include a porous ceramic material having the barium, and may have a polished external surface. An electron gun can include the filament assembly. An additive manufacturing system can include the electron gun having the filament assembly.

An electron source in a gas-source mass spectrometer the electron source comprising: an electron emitter cathode presenting a thermionic electron emitter surface in communication with a gas-source chamber of the gas-source mass spectrometer for providing electrons there to; a heater element electrically isolated from the electron emitter cathode and arranged to be heated by an electrical current therein and to radiate heat to the electron emitter cathode sufficient to liberate electrons thermionically from said electron emitter surface, therewith to provide a source of electrons for use in ionising a gas the gas-source chamber.

An electron source in a gas-source mass spectrometer the electron source comprising: an electron emitter cathode presenting a thermionic electron emitter surface in communication with a gas-source chamber of the gas-source mass spectrometer for providing electrons there to; a heater element electrically isolated from the electron emitter cathode and arranged to be heated by an electrical current therein and to radiate heat to the electron emitter cathode sufficient to liberate electrons thermionically from said electron emitter surface, therewith to provide a source of electrons for use in ionising a gas the gas-source chamber.

The present disclosure discloses a preparation method of pressed Scandia-doped dispenser cathode using microwave sintering. Embodiments of the present disclosure include dissolving some nitrates and ammonium metatungstate with deionized water to prepare a homogeneous solution. Precursor powder with uniform size is obtained by spray drying, the precursor powder is decomposed, and two-step reduction may be proceeded to form doped tungsten powder with uniform element distribution. The cathode is prepared by one-time microwave sintering. One-time forming of cathode sintering is realized, and sintering shrinkage and sintering time are reduced significantly. The method has excellent repeatability, and the cathode has a homogeneous structure and excellent emission performance at 950 C.

The invention relates to a cathode arrangement comprising: a thermionic cathode comprising an emission portion provided with an emission surface for emitting electrons, and a reservoir for holding a material, wherein the material, when heated, releases work function lowering particles that diffuse towards the emission portion and emanate at the emission surface at a first evaporation rate; a focusing electrode comprising a focusing surface for focusing the electrons emitted from the emission surface of the cathode; and an adjustable heat source configured for keeping the focusing surface at a temperature at which accumulation of work function lowering particles on the focusing surface is prevented.

The invention relates to a cathode arrangement comprising: a thermionic cathode comprising an emission portion provided with an emission surface for emitting electrons, and a reservoir for holding a material, wherein the material, when heated, releases work function lowering particles that diffuse towards the emission portion and emanate at the emission surface at a first evaporation rate; a focusing electrode comprising a focusing surface for focusing the electrons emitted from the emission surface of the cathode; and an adjustable heat source configured for keeping the focusing surface at a temperature at which accumulation of work function lowering particles on the focusing surface is prevented.

A thermionic dispenser cathode having a refractory metal matrix with scandium and barium compounds in contact with the metal matrix and methods for forming the same. The invention utilizes atomic layer deposition (ALD) to form a nanoscale, uniform, conformal distribution of a scandium compound on tungsten surfaces and further utilizes in situ high pressure consolidation/impregnation to enhance impregnation of a BaOCaOAl.sub.2O.sub.3 based emissive mixture into the scandate-coated tungsten matrix or to sinter a tungsten/scandate/barium composite structure. The result is a tungsten-scandate thermionic cathode having improved emission.