A secondary electron emissive layer resistant to infiltration and fouling. A barrier layer is formed by atomic layer deposition. The barrier layer may be an emissive layer and/or an interlayer. The barrier layer may form an interlayer that is a part of an electron amplifier positioned between an emissive layer and a resistive layer. The barrier layer is resistive to fluorine migration from either the emissive layer or the resistive layer.

An ultraviolet flame detector (100) includes a housing (102) having an opening (103) at a first end (101a) of the housing (102), and a window structure (104) arranged to cover the opening (103) of the housing (102). A photocathode (106) is arranged to a second end (101b) of the housing (102) so that the photocathode (106) is facing inside the housing (102). An anode wire (108) is arranged between the window structure (104) and the photocathode (106). The anode wire (108) is configured to travel transversally across the housing (102). The ultraviolet flame detector (102) is filled with a gas.

An ultraviolet flame detector (100) includes a housing (102) having an opening (103) at a first end (101a) of the housing (102), and a window structure (104) arranged to cover the opening (103) of the housing (102). A photocathode (106) is arranged to a second end (101b) of the housing (102) so that the photocathode (106) is facing inside the housing (102). An anode wire (108) is arranged between the window structure (104) and the photocathode (106). The anode wire (108) is configured to travel transversally across the housing (102). The ultraviolet flame detector (102) is filled with a gas.

A radiation dose rate monitor system includes an emitting electrode configured to be impinged by radiation radiation; a collecting electrode configured to form an electrical circuit with said emitting electrode, a current measurement device configured to measure a current through said emitting and collecting electrodes indicative of a dose of said radiation radiation, and a chamber enclosing a gas. Emission of secondary electrons from the emitting electrode provides a majority of the current.

A method of controlling the performance of a night vision device includes supplying, by a power supply, to a microchannel plate of a light intensifier tube, a control voltage that controls a gain of the microchannel plate, determining an amount of compensation to apply to the control voltage based on a change to the control voltage attributed to a change in temperature of an operating environment of the night vision device, adjusting the control voltage in accordance with the amount of compensation to obtain a compensated control voltage, and supplying, by the power supply, the compensated control voltage to the microchannel plate of the light intensifier tube. The method may further include determining whether the night vision device has been used for a predetermined amount of time, and only after that predetermined amount of time, is the method configured to supply the compensated control voltage.

A method of controlling the performance of a night vision device includes supplying, by a power supply, to a microchannel plate of a light intensifier tube, a control voltage that controls a gain of the microchannel plate, determining an amount of compensation to apply to the control voltage based on a change to the control voltage attributed to a change in temperature of an operating environment of the night vision device, adjusting the control voltage in accordance with the amount of compensation to obtain a compensated control voltage, and supplying, by the power supply, the compensated control voltage to the microchannel plate of the light intensifier tube. The method may further include determining whether the night vision device has been used for a predetermined amount of time, and only after that predetermined amount of time, is the method configured to supply the compensated control voltage.

The electron tube includes a vacuum container having a light transmitting substrate, a photocathode provided on an inner surface of the light transmitting substrate, an anode provided in the vacuum container, and a prism. The prism includes a bottom surface bonded to an outer surface of the light transmitting substrate, a light incident surface, and a light reflecting surface configured to further reflect light, which is incident to the photocathode through the prism and the light transmitting substrate and reflected at an interface between the photocathode and the vacuum space, so that the light is re-enter the photocathode. The light reflecting surface has an outwardly convex curved surface shape. The light incident surface is located inward of an imaginary spherical surface that is along the light reflecting surface.

The electron tube includes a vacuum container having a light transmitting substrate, a photocathode provided on an inner surface of the light transmitting substrate, an anode provided in the vacuum container, and a prism. The prism includes a bottom surface bonded to an outer surface of the light transmitting substrate, a light incident surface, and a light reflecting surface configured to further reflect light, which is incident to the photocathode through the prism and the light transmitting substrate and reflected at an interface between the photocathode and the vacuum space, so that the light is re-enter the photocathode. The light reflecting surface has an outwardly convex curved surface shape. The light incident surface is located inward of an imaginary spherical surface that is along the light reflecting surface.

A photoelectric tube includes a housing including a light transmitting portion, an electron emitting portion including a photoelectric surface disposed inside the housing, an electron capturing portion disposed between the light transmitting portion and the photoelectric surface inside the housing, and a conductive layer disposed on a light transmitting portion side of at least a part of the electron capturing portion to face the photoelectric surface inside the housing and configured to allow light to pass therethrough.

A photoelectric tube includes a housing including a light transmitting portion, an electron emitting portion held by a recess provided in the housing, the electron emitting portion including a concave photoelectric surface facing a light transmitting portion side inside the housing, and an electron capturing portion disposed between the light transmitting portion and the photoelectric surface inside the housing. At least a part of the electron capturing portion is located inside a region on an inside of the photoelectric surface.