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.

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.

An in-vacuum light sensor system, including a light sensor assembly comprising a photocathode configured for converting an impinging photon to a photoelectron, a semiconductor diode configured for multiplying the photoelectron impinging thereon, and a housing including vacuum-compatible materials configured for being placed in a vacuum chamber. The housing is configured for housing the photocathode and the semiconductor diode and for propagation of the photoelectron from the photocathode to the semiconductor diode. An electrical biasing subassembly is configured for electrically biasing at least the photocathode and the semiconductor diode, and the vacuum chamber is configured for positioning the light sensor apparatus therein.

An in-vacuum light sensor system, including a light sensor assembly comprising a photocathode configured for converting an impinging photon to a photoelectron, a semiconductor diode configured for multiplying the photoelectron impinging thereon, and a housing including vacuum-compatible materials configured for being placed in a vacuum chamber. The housing is configured for housing the photocathode and the semiconductor diode and for propagation of the photoelectron from the photocathode to the semiconductor diode. An electrical biasing subassembly is configured for electrically biasing at least the photocathode and the semiconductor diode, and the vacuum chamber is configured for positioning the light sensor apparatus therein.

An ion detection system comprising an upper plate configured for propagation of ions therethrough, a lower plate comprising a converter configured for converting ions impinging thereon to secondary electrons, a secondary electron multiplication assembly configured for receiving the secondary electrons and comprising at least one or optionally a series of oppositely facing pairs of dynodes, wherein in the optional series of oppositely facing pairs of dynodes, each pair is spaced apart from an adjacent pair, and wherein a first electric field is created in between the oppositely facing pair of dynodes. A magnetic system is provided for generating a magnetic field.

An optical tissue imaging system includes a probe for insertion into a transparent cylindrical capillary. The capillary includes an internal cylindrical channel that extends along a central axis. The capillary is inserted into tissue of a subject, and the probe may rotate and translate within the capillary. The probe may include a mirror configured to reflect light to the tissue outside of the cylindrical capillary.

An optical tissue imaging system includes a probe for insertion into a transparent cylindrical capillary. The capillary includes an internal cylindrical channel that extends along a central axis. The capillary is inserted into tissue of a subject, and the probe may rotate and translate within the capillary. The probe may include a mirror configured to reflect light to the tissue outside of the cylindrical capillary.

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.

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 photomultiplier includes a housing including a proximal end and a distal end, an optical window disposed at the proximal end of the housing, an end-wall plate disposed at the distal end of the housing, a feedthrough that penetrates through the end-wall plate, and a gas electron multiplier (GEM) board disposed between the optical window and the end-wall plate.