20 results about "Thermionic emission" patented technology

Thermionic generators are described herein that include a variety of features that allow the devices to efficiently and effectively convert large amounts of thermal energy directly to electrical energy, such as in the form of currents and / or voltages. For example, the thermionic generators can be used to generate an electron beam from a thermionic emission device, and focus or shape the electron beam in such a way that allows the energy of electrons in the electron beam to be captured and converted to electrical energy.

The invention provides cathodoluminescent lamps with improved optical stability and extended lifetimes through advanced enclosure and electron emission configurations. A filament emits electrons via thermionic emission, which are accelerated by an anode toward a cathodoluminescent emitter to produce photons. The vacuum enclosure comprises glass, fused silica, and metal portions coupled with vacuum-compatible epoxy, with the metal providing thermal and electrical conduction. The lamp can include anode current monitoring and filament power control to stabilize emission. An electrically activated getter maintains vacuum conditions by chemically bonding contaminants and can be refreshed over time. The designs enable effective vacuum maintenance, stable operation, and long-term reliability suitable for commercial applications.

The application discloses a method for inhibiting thermionic emission based on TTM-MD simulation, which adjusts the energy distribution and delay time of double pulses to regulate the electron temperature, and obtains the maximum delay time introduced under the condition of meeting the processing requirements according to the relationship between the temperature rising time and the delay. The method can obtain the maximum delay introduced under the condition of meeting the processing requirements, reduces the electron temperature, and inhibits the thermionic emission.

A dielectric layer of a semiconductor device may be treated using an oxidation treatment process to tune the dielectric constant of the dielectric layer. For example, an etch stop layer (ESL) in an interconnect layer of the semiconductor device may be formed of a high dielectric constant (high-k) dielectric material, which provides etch selectivity for the ESL relative to other dielectric layers in the interconnect layer. A recess may be formed through the ESL and through the dielectric layers, and a conductive structure may be formed in the recess. Prior to formation of the conductive structure, an oxidation treatment operation may be performed to oxidize the exposed ends of the ESL in the recess. The oxidation treatment may lower the dielectric constant of the ends of the ESL, which may result in the ends of the ESL being less susceptible to current leakage through tunneling, hot-carrier injection, and / or thermionic emission.

The present disclosure relates to a system which may have an electronic controller, an optical light source controlled by the electronic controller which generates a beam having an output power level, and a current measuring subsystem (CMS) electrically coupled to a conductive substrate (e.g., metal substrate (MS)) while a powder bed layer (PBL) is deposited on the MS. The CMS may be in communication with the electronic controller and detects a current flow as at least one of the MS or the PBL is heated when the beam is scanned over the PBL. The CMS generates a current flow signal in accordance with the detected current flow. The current flow signal is used by the electronic controller to determine when the temperature of at least one of the substrate or the PBL is at least one of above or below a desired temperature.

The invention discloses a Schottky diode device and a preparation method thereof, and belongs to the technical field of power semiconductors. The Schottky diode device comprises an N-type substrate layer, an N-type buffer layer, a first N-type epitaxial layer, a first P-type region, a second N-type epitaxial layer, a second P-type region, an anode ohmic metal contact layer, an anode Schottky metal contact layer, an anode metal layer and a cathode metal layer. Wherein the upper surface of the second N-type epitaxial layer comprises a plurality of grooves, so that the Schottky metal contact area and the ohmic metal contact area are increased, the conduction voltage drop can be reduced, and the anti-surge capability of the device is improved. According to the double-layer epitaxial structure, the doping concentration at the interface of Schottky metal and a semiconductor is improved, a depletion layer on the Schottky contact surface is narrowed, the hot electron emission current is increased, the effective barrier height is reduced, the tunneling effect is enhanced, and the conduction voltage drop is reduced. While low conduction voltage drop and low reverse leakage current are taken into consideration, the stability and reliability of the device under high surge current are remarkably improved.

The application relates to a non-stoichiometric carbide doped tungsten-based thermionic cathode material and a preparation method thereof, and belongs to the technical field of refractory metal cathode materials. Zirconium carbide, hafnium carbide and titanium carbide are respectively mixed with their respective hydrides or graphite by using a high-energy ball milling technology, and then mixed with tungsten powder to obtain non-stoichiometric carbide doped tungsten powder with C "vacancies" or non-stoichiometric carbide doped tungsten powder with metal element "vacancies", and then the non-stoichiometric carbide doped tungsten-based thermionic cathode is prepared by means of pressing, vacuum sintering at 1600-2100 DEG C. The thermionic cathode material has the advantages of simple preparation process, high cathode density of 99%, and the highest emission current density of 1.63 A / cm 2 at 1600 DEG C, which is about 30% higher than that of a standard stoichiometric carbide, and the thermionic emission performance is 3 times higher than that of a pure metal cathode.

According to the model and the simulation method for emitting the microscopic hot electrons to the macroscopic electromagnetic pulse, particle simulation and three-dimensional electromagnetic field simulation are innovatively coupled, and full-chain integrated simulation from microscopic particle dynamics to macroscopic electromagnetic radiation is realized; the technical problem that a micromechanism and macroscopic performance are disjointed in a traditional simulation method is effectively solved; meanwhile, the method has good universality and adaptability, and influences of multiple factors such as laser parameters, target material characteristics and experimental environments can be fully considered. By adjusting simulation parameters, electromagnetic pulse characteristics under different experiment conditions can be accurately predicted, and reliable theoretical guidance is provided for optimizing an experiment design scheme. The method is not only suitable for performance evaluation of an existing laser device, but also can provide technical support for electromagnetic pulse management of a higher-power laser device in the future.

X-ray tubes that have a reduced exposure time for dental X-ray imaging and 3D dental imaging systems using these X-ray tubes are described. The X-ray tubes contain an anode, a filament, a cathode electrically connected to the filament, and a voltage source electrically connected to the cathode. The voltage source provides a high voltage to the anode relative to the cathode and filament control voltage. A low filament control voltage is used to generate electrons using a process of thermionic emission. These electrons are driven by a large electric field generated between the cathode and anode towards the target on the anode. A bias voltage is applied between the cathode and the filament to control the electron flow from the emitting filament to the anode. Such a configuration yields a switching speed ranging from about 1 ms to about 10 ms, allowing a short X-ray exposure time and a quicker overall imaging process for the 3D dental X-ray imaging systems. Other embodiments are described.

This invention belongs to the field of optoelectronics technology, specifically relating to a narrowband near-infrared thermionic photodetector, its fabrication method, and its applications. A top-layer metal grating absorbs near-infrared light, generating thermionic electrons that are injected into an ultrathin silicon film, where they are collected by the bottom electrode to form a photocurrent. The top-layer metal grating forms a Schottky contact with the silicon thin film, enabling near-infrared light detection below the silicon energy bandgap. The small thickness of the metal grating increases photoemission within the metal, providing more opportunities for thermionic emission over the Schottky barrier, further improving the photodetector efficiency. Simultaneously, by adjusting the width of the metal grating, the resonant wavelength of the detector can be changed, achieving a wavelength-tunable near-infrared photodetector. Due to the thinness of silicon, applying a small bias voltage can induce a strong electric field in the silicon film, triggering an avalanche multiplication effect. This invention broadens the operating wavelength range of traditional silicon-based photodetectors and achieves tunable peak responsivity, showing great promise for applications in silicon-based optoelectronic devices.

The invention provides a large-size cerium hexaboride single crystal, a preparation method of the large-size cerium hexaboride single crystal and a thermionic emitter comprising the large-size cerium hexaboride single crystal. The diameter of the large-size cerium hexaboride single crystal is more than 10mm. The large-size cerium hexaboride single crystal disclosed by the invention is high in quality, good in performance and excellent in emission current density.

To provide an ion source and an accelerator, as well as a method for generating ions and accelerating those ions in the ion source.SOLUTION: A nuclear reaction generation device includes a chamber configured to contain gas and include a target. The nuclear reaction generation device also includes a filament provided within the chamber and a voltage source configured to apply a first positive voltage to the filament relative to the chamber. The first positive voltage is configured to heat the filament to a temperature that causes thermionic emission and generates multiple thermions. The multiple thermions are configured to ionize the gas and generate positive ions in the chamber. The target is configured such that nuclear reactions occur when the positive ions interact with the target.SELECTED DRAWING: Figure 1

The invention provides a heat flow and temperature composite sensor based on hot electron emission and a measurement method, relates to the field of thermotechnical measurement, and aims to solve the problems that high-precision in-situ, synchronous and reliable monitoring is difficult to realize due to separated measurement in an extremely high-temperature and high-heat-flow environment in the conventional thermotechnical measurement technology. The method comprises the following steps: placing a hot electron cathode of the sensor in a to-be-measured heat flow field, and enabling the hot electron cathode to absorb heat flow and raise the temperature; after the hot electron cathodes are heated to generate hot electron emission, electron flows are formed between the hot electron cathodes and the corresponding hot electron anodes; collecting a net current signal generated by the electron flow through a closed loop connected with the thermionic cathode and the thermionic anode; and on the basis of a thermal-electric double-parameter decoupling model, synchronously resolving the net current signal to obtain the corresponding heat flux density and the temperature of the thermionic cathode. According to the invention, problems in the prior art are solved, and double physical quantities of heat flux density and temperature can be synchronously inverted with high precision.

The invention discloses a heat storage-heat and power cogeneration device and method based on thermal electron and capacitor integrated energy storage and transduction, and the device comprises a heat storage body, and a thermal electron emission unit and a capacitor energy storage unit which are located at the inner periphery of the heat storage body. The thermionic emission unit comprises a thermionic positive electrode located on the inner circumferential wall of the heat storage body and a negative electrode located on the inner circumference of the thermionic positive electrode, the capacitive energy storage unit comprises a negative electrode and a capacitive positive electrode located on the inner circumference of the negative electrode, and the thermionic emission unit and the capacitive energy storage unit share the same negative electrode. The thermal electron emission effect and the capacitance electricity storage are designed to be of an integrated structure and share the same negative electrode, heat storage, thermoelectric conversion and electricity storage are coupled into the same physical process, the structure is simple and compact, and the purposes of long-time large-capacity storage-discharge / heat with high energy density, high power density and transient response are achieved.

And an ion source having a thermionic emission cathode coupled to the plasma chamber and exposed to the plasma chamber environment. The first power source is coupled to a first filament associated with the thermionic emission cathode and is configured to selectively supply a first power to the first filament to heat the first filament to a first temperature and induce thermionic emission from the thermionic emission cathode. A non-thermal electron emission cathode is coupled to the plasma chamber and exposed to the plasma chamber environment. A second power source supplies a second power to a second filament associated with the non-thermal electron emission cathode and heats the second filament and the non-thermal electron emission cathode to a second temperature while not inducing thermal electron emission from the non-thermal electron emission cathode, thereby minimizing condensation within the plasma chamber environment. The controller may control the first power source and the second power source to provide constant power or emission.

Provided is a negative ion source and a negative ion generation method capable of providing a high negative ion generation efficiency. A negative ion source includes a housing that includes: an inlet from which a sample is introduced; a plasma generation region communicated with the inlet, a plasma being generated by discharge in the plasma generation region; a negative ion generation region in which particles dissociated or excited by a reaction of the generated plasma with the sample are converted into negative ions; and an extraction port communicated with the negative ion generation region, the generated negative ions being extracted outside through the extraction port. The negative ion generation region is filled with a thermionic emission material for generating thermoelectrons by high frequency heating.

An electron emitter according to one or more example embodiments for a rotary piston X-ray tube has a segmented emitter surface including at least two emitter elements which can be activated independently of each other and is set up to activate at least one subset of the segments of the segmented emitter surface as an activated emission surface for emitting electrons from the activated emission surface, wherein the at least two emitter elements are arranged in such a way that the segmented emitter surface is axially symmetrical in an emitter surface place, at least one emitter element of the at least two emitter elements is embodied for the thermionic emission of electrons, and the at least two emitter elements are arranged such that a distance between the respective emitter surfaces is minimal.

The application provides a working medium-free micro thermionic emission device, which comprises an extraction electrode, an electron emitter, a heating assembly, a shielding cover, an insulating connecting piece and a supporting cylinder; the extraction electrode is arranged outside the supporting cylinder, and the electron emitter and the heating assembly are arranged inside the supporting cylinder; the heating assembly is used for heating the electron emitter so that the electron emitter emits a thermionic emission current; the central axis of the electron emitter corresponds to an extraction hole on the extraction electrode; a gap exists between the emission end face of the electron emitter and the extraction electrode; the two ends of the insulating connecting piece are connected with the outer side wall of the supporting cylinder and the inner side wall of the extraction electrode respectively; the shielding cover is arranged on the circumferential side of the supporting cylinder, and a gap exists between the shielding cover and the supporting cylinder. The electron emission device of the application can be used as an electron source for a tether propulsion system, and can greatly improve the performance of the propulsion system, simplify the system structure, reduce the weight and complete space tasks such as orbit transfer of a spacecraft or de-orbiting at the end of the life of the spacecraft.

The utility model discloses a heat dissipation formula X ray tube, it includes glass shell, glass shell one end is provided with cathode assembly, glass shell one end is provided with anode assembly, and cathode assembly generates free electron through thermionic emission process, and anode assembly absorbs free electron and generates X ray, and glass shell outside fixedly connected with metal protective housing, and the metal protective housing bottom is provided with the through slot, and the electromagnetic coil is activated and produces the rotation magnetic field and gives birth to permanent magnet and drives target block rotation, and the electron that tungsten wire emits spreads to the larger area, and the heat capacity of X ray tube is increased significantly, and the insulating oil carries out heat exchange first during tungsten wire heating process, and simultaneously, the anode tube drives second bevel gear rotation, and the cooperation of second bevel gear and first bevel gear drives second pulley rotation, and under the action of transmission belt, the fan blade produces the downward airflow, and the airflow is discharged from the air outlet and carries out the cooling of insulating oil, and the inclined plane air deflector changes the wind direction, prevents the hot airflow and directly blows to the X ray irradiation place.