A radiotherapy dose rate monitor system includes an emitting electrode configured to be impinged by radiotherapy 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 radiotherapy radiation, and a chamber enclosing a gas. Emission of secondary electrons from the emitting electrode provides a majority of the current.

In an electron tube, the meta-surface emits an electron in response to an incidence of the electromagnetic wave. The first and second electrodes are spaced away from each other, and apply potentials different from each other to the meta-surface. A holder is disposed in the housing and holds the electron emitter. A first conductive line of the meta-surface is electrically connected to the first electrode. A second conductive line of the meta-surface is spaced away from the first conductive line, and is electrically connected to the second electrode. The first conductive line extends from the first electrode to the second conductive line. The second conductive line extends from the second electrode to the first conductive line.

A radiotherapy dose rate monitor system includes an emitting electrode configured to be impinged by radiotherapy 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 radiotherapy radiation, and a chamber enclosing a gas. Emission of secondary electrons from the emitting electrode provides a majority of the current.

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 solar generator can include a photon-enhanced thermionic emission generator with a cathode to receive solar radiation. The photon-enhanced thermionic emission generator can include an anode that in conjunction with the cathode generates a first current and waste heat from the solar radiation. A thermoelectric generator can be thermally coupled to the anode and can convert the waste heat from the anode into a second current. A circuit can connect to the photon-enhanced thermionic emission generator and to the thermoelectric generator and can combine the first and the second currents into an output current.

A solar generator can include a photon-enhanced thermionic emission generator with a cathode to receive solar radiation. The photon-enhanced thermionic emission generator can include an anode that in conjunction with the cathode generates a first current and waste heat from the solar radiation. A thermoelectric generator can be thermally coupled to the anode and can convert the waste heat from the anode into a second current. A circuit can connect to the photon-enhanced thermionic emission generator and to the thermoelectric generator and can combine the first and the second currents into an output current.

In-situ methods for the batch fabrication of flat-panel micro-channel plate (MCP) photomultiplier tube (PMT) detectors (MCP-PMTs), without transporting either the window or the detector assembly inside a vacuum vessel are provided. The method allows for the synthesis of a reflection-mode photocathode on the entrance to the pores of a first MCP or the synthesis of a transmission-mode photocathode on the vacuum side of a photodetector entrance window.

In-situ methods for the batch fabrication of flat-panel micro-channel plate (MCP) photomultiplier tube (PMT) detectors (MCP-PMTs), without transporting either the window or the detector assembly inside a vacuum vessel are provided. The method allows for the synthesis of a reflection-mode photocathode on the entrance to the pores of a first MCP or the synthesis of a transmission-mode photocathode on the vacuum side of a photodetector entrance window.

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.