The embodiments provide a thermionic emission device and a method for tuning a work function in a thermionic emission device is provided. The method includes illuminating an N type semiconductor material of a first member of a thermionic emission device, wherein a work function of the N type semiconductor material is lowered by the illuminating. The method includes collecting, on one of the first member or a second member of the thermionic emission device, electrons emitted from one of the first member or the second member.

The embodiments provide a thermionic emission device and a method for tuning a work function in a thermionic emission device is provided. The method includes illuminating an N type semiconductor material of a first member of a thermionic emission device, wherein a work function of the N type semiconductor material is lowered by the illuminating. The method includes collecting, on one of the first member or a second member of the thermionic emission device, electrons emitted from one of the first member or the second member.

A method includes performing by a processor: estimating a total cathode space current for a thermionic vacuum tube having at least one grid and a plate, such that at least one amplification factor associated with the at least one grid is determined by a polynomial based on a variable that represents at plurality of voltages associated with the at least one grid and the plate, the variable being heuristically determine. Transitions between positive and negative grid operation may experience a step change in estimated current value caused by the inclusion or elimination of grid current. A part of the grid current may be added back into the plate current during transition. This small contribution to plate current may gradually diminish as tube operation moves farther away from the transition boundary.

A method includes performing by a processor: estimating a total cathode space current for a thermionic vacuum tube having at least one grid and a plate, such that at least one amplification factor associated with the at least one grid is determined by a polynomial based on a variable that represents at plurality of voltages associated with the at least one grid and the plate, the variable being heuristically determine. Transitions between positive and negative grid operation may experience a step change in estimated current value caused by the inclusion or elimination of grid current. A part of the grid current may be added back into the plate current during transition. This small contribution to plate current may gradually diminish as tube operation moves farther away from the transition boundary.

An electron generating apparatus includes a filament, a power supply configured to supply power to the filament so as to make the filament emit an electron, and a controller configured to repeatedly detect a value having a correlation with power supplied from the power supply to the filament, determine whether a state of the filament satisfies a notification condition, by using a plurality of detected values, and perform notification when the state satisfies the notification condition.

An electron generating apparatus includes a filament, a power supply configured to supply power to the filament so as to make the filament emit an electron, and a controller configured to repeatedly detect a value having a correlation with power supplied from the power supply to the filament, determine whether a state of the filament satisfies a notification condition, by using a plurality of detected values, and perform notification when the state satisfies the notification condition.

Provided is a field emission apparatus including a pipe-shaped emitter holder comprising an electrically conductive material and a first internal space communicated in a first direction, and an emitter electrode having one or more yarns each having a structure extending in the first direction in which a plurality of CNTs that extend in the first direction are aggregated, and the emitter electrode is inserted in the first internal space while extending in the first direction.

Provided is a field emission apparatus including a pipe-shaped emitter holder comprising an electrically conductive material and a first internal space communicated in a first direction, and an emitter electrode having one or more yarns each having a structure extending in the first direction in which a plurality of CNTs that extend in the first direction are aggregated, and the emitter electrode is inserted in the first internal space while extending in the first direction.

A receptacle for receiving a plug connector of a high-voltage cable for a microfocus X-ray tube with a cathode, which has a metal filament and grid cap. The receptacle has a ceramic insulator with three contiguous cavities. The first cavity near the filament includes electrical contacts for the filament and the grid cap. The second cavity includes spring contacts for supplying current to the filament and a center pin for supplying voltage to the grid. The third cavity receives the plug connector. The insulator has a removable grid mounting which is conductively connected to the grid cap of the cathode. The first and second cavities are surrounded in the radial direction by the grid mounting. An air gap extends radially between grid mounting and ceramic body. At the end of the grid mounting remote from the filament is a circumferential groove in the axial direction between the grid mounting and the ceramic insulator.

A vacuum electron tube comprises at least one electron-emitting cathode and at least one anode arranged in a vacuum chamber, the cathode having a planar structure comprising a substrate comprising a conductive material, a plurality of nanotube or nanowire elements electrically insulated from the substrate, the longitudinal axis of the nanotube or nanowire elements substantially parallel to the plane of the substrate, and at least one first connector electrically linked to at least one nanotube or nanowire element so as to be able to apply a first electrical potential to the nanowire or nanotube element.