An electron tube includes a housing having a window having an electromagnetic wave transmitting property, an electron emission plate disposed inside the housing, the electron emission plate emitting electrons, and a holding member disposed inside the housing and configured to hold the electron emission plate and to apply a voltage to the electron emission plate. The electron emission plate has a first main surface and a second main surface facing each other. The holding member has a base portion being in contact with the first main surface, and a plurality of electron emission plate biasing portions which are in contact with an edge of the second main surface and are configured to elastically bias the electron emission plate to the base portion. The holding member is electrically connected to the second main surface through the plurality of electron emission plate biasing portions.

A flame detector that includes a spacer, a UV transparent window, and a UV sensing elements. The spacer has a spacer wall that extends along a first axis between a first spacer end and a second spacer end. The UV transparent window is disposed at the first spacer end. The spacer wall and the UV transparent window define a gas space. The UV sensing elements is disposed within the gas space.

A flame detector that includes a spacer, a UV transparent window, and a UV sensing elements. The spacer has a spacer wall that extends along a first axis between a first spacer end and a second spacer end. The UV transparent window is disposed at the first spacer end. The spacer wall and the UV transparent window define a gas space. The UV sensing elements is disposed within the gas space.

An image intensifier sensor for acquiring, amplifying and displaying images and including a vacuum envelope, the image intensifier sensor including a photocathode arranged for releasing photoelectrons into the vacuum envelope upon electromagnetic radiation acquired from the images which impinges the photocathode, an anode, spaced apart from and in facing relationship with the photocathode, arranged for receiving the photoelectrons and converting the photoelectrons for displaying the images on the basis thereof, and a power supply unit for providing power to the image intensifier sensor, wherein the image intensifier sensor further includes potting material, wherein the potting material comprises a foam compound.

An image intensifier sensor for acquiring, amplifying and displaying images and including a vacuum envelope, the image intensifier sensor including a photocathode arranged for releasing photoelectrons into the vacuum envelope upon electromagnetic radiation acquired from the images which impinges the photocathode, an anode, spaced apart from and in facing relationship with the photocathode, arranged for receiving the photoelectrons and converting the photoelectrons for displaying the images on the basis thereof, and a power supply unit for providing power to the image intensifier sensor, wherein the image intensifier sensor further includes potting material, wherein the potting material comprises a foam compound.

A novel photocathode employing a conduction band barrier is described. Incorporation of a barrier optimizes a trade-off between photoelectron transport efficiency and photoelectron escape probability. The barrier energy is designed to achieve a net increase in photocathode sensitivity over a specific operational temperature range.

A novel photocathode employing a conduction band barrier is described. Incorporation of a barrier optimizes a trade-off between photoelectron transport efficiency and photoelectron escape probability. The barrier energy is designed to achieve a net increase in photocathode sensitivity over a specific operational temperature range.

The present invention improves sensitivity of the ultraviolet band of a photoelectric surface. A photoelectric surface includes a window material that transmits ultraviolet rays, a conductive film that is formed on the window material and has conductivity, an intermediate film 4 that is formed on the conductive film and is formed of MgF.sub.2, and a photoelectric conversion film that is formed on the intermediate film 4 and is formed of CsTe. Since the photoelectric surface includes the intermediate film 4 formed of MgF.sub.2, the sensitivity of the ultraviolet band is improved.

The present invention improves sensitivity of the ultraviolet band of a photoelectric surface. A photoelectric surface includes a window material that transmits ultraviolet rays, a conductive film that is formed on the window material and has conductivity, an intermediate film 4 that is formed on the conductive film and is formed of MgF.sub.2, and a photoelectric conversion film that is formed on the intermediate film 4 and is formed of CsTe. Since the photoelectric surface includes the intermediate film 4 formed of MgF.sub.2, the sensitivity of the ultraviolet band is improved.

A first member made of an insulating material and a jig with a protrusion narrowing toward a distal end side are prepared, and at least one of the first member and the jig is heated to a temperature at which the first member can melt and deform. After the jig is brought into contact with the first member with the first member and the plurality of protrusions facing each other, the jig is removed, and an intermediate body is formed including the first member formed with a plurality of recesses, and a plurality of conductive members passing through the first member and projecting into the recesses. A second member is prepared, openings of the plurality of recesses are closed, and the second member is hermetically joined to the intermediate body to form a plurality of internal spaces where electron is emitted, and forming a joined body.