312 results about "Photocathode" patented technology

The invention discloses a high-speed multi-photon detection system and method. The system comprises a detector and a signal processing circuit, wherein the detector is composed of a window plated with a photoelectric cathode, a micro-channel plate stack and an anode; a plurality of incident photons are converted into a plurality of photoelectrons by the photoelectric cathode, and the photoelectrons are converted into electron cloud by the micro-channel plate stack; the incident electron cloud is divided into multiple paths by three layers of staggered metal strip electrodes of the anode, and charge collection is carried out to obtain charge short pulses of each layer of electrode; the signal processing circuit converts the charge short pulses transmitted by the three layers of electrodes into digital pulse signals, obtains the centroid coordinates of the electron cloud from the digital pulse signals as the abscissa value, the ordinate value and the verification value of the incident photon position, combines the abscissa value, the ordinate value and the verification value based on the screening condition to obtain the target two-dimensional coordinates, and finally obtains the target two-dimensional coordinates. And transmitting to a terminal for imaging display. According to the invention, a plurality of synchronous photons can be detected, the overall counting rate of the detector is greatly improved, and the detection efficiency is improved.

The invention belongs to the technical field of immunoassay and biosensing, and provides a novel construction mode of a heterojunction dual-photoelectrode photoelectric sensing strategy and a preparation method of an in-situ heterojunction MIO photocathode. The invention relates to a preparation method of a heterojunction dual-photoelectrode type photoelectrochemical sensor based on multi-ball cascade DNA reaction amplification. Specifically, the design is composed of an In2O3 / CdS photoanode and an in-situ formed MIL-68 / In2O3 (MIO) photocathode. The heterojunction dual-photoelectrode sensing strategy effectively prolongs an electron-hole transmission path, enhances photo-generated charge separation, and realizes' super-open 'PEC signal output, thereby providing a steady baseline for signal conversion. Meanwhile, a multi-sphere cascade DNA reaction is combined to output a three-dimensional DNA net structure to provide a large number of sites for embedding of a PEC quenching probe doxorubicin-ferrocene carboxylic acid (DOX-FcCOOH), obvious PEC signal quenching is realized by utilizing the efficient competitive electron transfer capability of the three-dimensional DNA net structure, and finally, a signal conversion system with'opening-super opening-closing 'multistage response characteristics is constructed. The detection of the nucleic acid marker Pax-5a gene of the B cell acute lymphatic leukemia is realized by detecting target objects with different concentrations.

To provide a photodetector capable of protecting a semiconductor photodetector element from reflected electrons generated inside a vacuum enclosure.SOLUTION: A photodetector 1 includes a vacuum housing 2 having a window 12, a photocathode (first photoelectric conversion layer) 3 that emits electrons E in response to incidence of light L1, a phosphor layer (second photoelectric conversion layer) 4 that generates light L2 in response to incidence of the electrons E emitted from the photocathode 3, and a semiconductor photodetector element 5 that is disposed on the opposite side of the photocathode 3 with the phosphor layer 4 in between and detects the light L2 generated in the phosphor layer 4. The semiconductor photodetector element 5 is disposed at a distance from the phosphor layer 4.SELECTED DRAWING: Figure 1

The invention discloses a nano-pillar array NaKSb photoelectric cathode for enhancing light absorption, which is characterized in that through the design of a double-layer TiOtwo-dimensional nano grating and a nano-pillar array structured NaKSb photoelectric cathode layer, the optical path of light with the wave band of 450-900 nm in the photoelectric cathode is increased under the condition that the thickness of the NaKSb photoelectric cathode is not increased, the reflectivity of the wave band of 400-600 nm is reduced, and the light absorption of the NaKSb photoelectric cathode is enhanced. The absorption rate at 400-1000 nm is improved by 32.28% compared with that of a traditional planar film type photoelectric cathode, the absorption rate at 800-1000 nm near-infrared band is improved by 40.27% compared with that of the traditional planar film type photoelectric cathode, the problem that the absorption of the traditional planar film type photoelectric cathode near-infrared band is insufficient is solved, and the photoelectric cathode is suitable for high-performance low-light night vision imaging devices.

The invention relates to a photon counting imaging detector, in particular to a photon counting imaging detector with multiband composite detection capability, and solves the technical problem that an existing position-sensitive anode detector cannot detect multiple bands at the same time. The photon counting imaging detector with the multiband composite detection capability comprises a vacuum packaging tube body array, and a position-sensitive anode assembly, a detector frame and a detector end cover which are sequentially connected from bottom to top, the receiving ends of the vacuum packaging tube bodies are upwards arranged in the mounting block, and the N * M receiving ends of the vacuum packaging tube bodies are respectively provided with the same or different photoelectric cathodes for receiving target optical signals of different wavebands and converting the target optical signals into photoelectrons; the output ends of the N * M vacuum packaging tube bodies are respectively provided with a high-resistance collecting layer for receiving the photoelectrons and converting the photoelectrons into electronic cloud cluster signals for outputting; and the position-sensitive anode assembly is used for sensing an electron cloud cluster signal and transmitting the electron cloud cluster signal to an external readout electronics system for processing.

Image intensifier systems incorporating a microchannel plate (MCP) and methods for producing the same are disclosed. A device is disclosed that includes a first substrate having a radiation-receiving first surface and an opposed second surface through which electromagnetic radiation is transmitted. A second substrate is coupled to the first substrate to define a vacuum cavity therebetween having electron-emitting photocathode is disposed therein. A microchannel plate (MCP) is disposed within the vacuum cavity and defines microchannels extending from an input end to an output end. Each of the microchannels is configured to generate / amplify electrons in response to the electrons received photocathode. The imaging array can include a plurality of metal plates connected to capacitors and configured to collect electrons from the MCP to produce a digital image responsive to electromagnetic radiation received at the first substrate and converted to electrons by the photocathode and multiplied by the MCP.

An object is to provide an electron beam applicator suitable for an electron gun having a photocathode and an electron beam emission method in the electron beam applicator. The object can be achieved by an electron beam applicator including: an electron gun section; a main body section; and a control unit. The electron gun section includes a light source, a photocathode that emits an electron beam in response to receiving excitation light emitted from the light source, and an anode. The main body section includes an objective lens that converges an electron beam emitted from the electron gun section. The control unit controls at least convergence power of the objective lens in accordance with a size of an electron beam emitted from the photocathode.

A back illuminated sensor is included as a collector component of a detector for use in intraoral and extraoral 2D and 3D dental radiography, digital tomosynthesis, photon-counting computed tomography, positron emission tomography (PET), and single-photon emission computed tomography (SPECT). The disclosed imaging method includes one or more intraoral or extraoral emitters for emitting a low-dose gamma ray or x-ray beam through an examination area; and one or more intraoral or extraoral detectors for receiving the beam, each detector including a back illuminated sensor. Within the detector, the beam is converted into light and then focused and collected at a photocathode layer without passing through the wiring layer of the back illuminated sensor.

The invention belongs to the technical field of corrosion inhibition of ocean engineering structure metal materials, and particularly relates to a double-Z-type heterojunction photo-anode film and a preparation method and application thereof. The preparation method of the double-Z-type heterojunction photo-anode film comprises the following steps: (1) placing conductive glass with a conductive surface facing downwards in a first solution containing a cadmium salt, an indium salt and a sulfur source, and carrying out a first hydrothermal reaction to obtain a CdIn2S4 film; (2) putting the CdIn2S4-ZnS composite film into a second solution containing zinc salt and a sulfur source with the conductive surface facing downwards, and carrying out a second hydrothermal reaction to obtain a CdIn2S4-ZnS composite film; and (3) putting the CdIn2S4-ZnS-Zn3In2S6 composite film into a third solution containing a zinc salt, an indium salt and a sulfur source with the conductive surface facing downwards, and carrying out a third hydrothermal reaction to obtain the CdIn2S4-ZnS-Zn3In2S6 composite film. According to the double-Z-type heterojunction photo-anode film, efficient photoelectric cathode protection of an ocean engineering structure can be achieved, and the durability of the ocean engineering structure is improved.

The invention provides a wide-spectrum dual-photoelectrode-based photoelectrochemical sensor and a preparation method and application thereof, and belongs to the technical field of photoelectrochemical sensors. According to the photoelectrochemical sensor provided by the invention, a BCN / ITO electrode is used as a photoanode, a CuInS2 / ITO electrode is used as a photocathode, BCN is Bi2S3 / C3N4, and ITO is indium tin oxide. The sensor is used for detecting enrofloxacin and ciprofloxacin pollution. According to the present invention, the surface is modified with the aptamer having the specific recognition function, the specific binding effect of the aptamer with the enrofloxacin and the ciprofloxacin is utilized to form the complex of the aptamer and the target object, and the influence of the caused steric hindrance effect on the photoelectric signal and the dual-channel strategy are utilized to achieve the simultaneous detection of the residual marker; the linear ranges for detecting enrofloxacin and ciprofloxacin are 0.1 nM to 1 mu M and 50 pM to 0.5 mu M respectively, the detection limits are 24 pM and 15.5 pM respectively, and the method is successfully applied to simultaneous detection of residual markers in water. The method has the advantages of greenness, environmental protection, wide detection range, high sensitivity, good selectivity and high stability.

The application discloses a 200kV direct-current type high-voltage photoelectron gun, wherein a cathode electrode and an anode electrode adopt a multi-section curved surface structure design, and the front surface structures are symmetrically distributed, so that the risk of vacuum breakdown caused by local field enhancement of the direct-current high-voltage electron gun is reduced; a displacement adjusting structure is installed on the anode electrode, so that the distance between the anode electrode and the cathode electrode can be adjusted, and then the working voltage of the electron gun can be adjusted within 50-200kV; a photocathode transfer device is installed in the cathode electrode, and is used for replacing different types of photocathodes or damaged photocathodes; meanwhile, transmission and reflection type two photocathode working modes are arranged, and in the reflection type working mode, a detection laser can realize 15° and 45° two angle incidences, so that the direct-current type high-voltage electron gun has higher expansibility, and can be expanded to more application fields.

The invention relates to the technical field of detection, and discloses an MCP image enhancement high-sensitivity detection system, which comprises a photoelectric cathode, which adopts a multi-quantum well structure and a surface plasma enhancement technology, is used for converting incident photons into primary electrons, and comprises a quantum well formed by gallium arsenide and gallium aluminum arsenide; a microchannel plate for amplifying primary electrons generated from the photocathode; the microchannel plate is coated with a superconducting thin film so as to reduce noise and improve electronic gain; various types of sensors include optical sensors, thermal imaging sensors, acoustic sensors, and chemical sensors. By adopting a multi-quantum well structure and a surface plasma enhanced photoelectric cathode, the spectral response and photoelectric conversion efficiency are remarkably improved, and the sensitivity and response speed of the system to non-specific wavelengths are enhanced. Meanwhile, the microchannel plate coated with the superconducting thin film effectively reduces the noise level, improves the signal definition and the image quality, and solves the high-gain limitation of a traditional system.

This invention discloses an energy storage type TiO2 / CN X The photoanode of WO3 composite material and its preparation method include the following steps: preparing WO3 nanorods by hydrothermal method; adding WO3 nanorods and anionic surfactant to water, sonicating, adding pyrrole, stirring, and then adding an initiator solution dropwise under ice bath conditions, stirring, and obtaining WO3 / PPy composite after reaction; adding WO3 / PPy composite and anionic surfactant to an alcohol solution, sonicating and stirring, adding tetrabutyl titanate, glacial acetic acid and acetone, and then adding an aqueous alcohol solution dropwise, transferring to a hydrothermal reactor for reaction, obtaining precursor TiO2 / PPy / WO3 composite after hydrothermal reaction; loading the precursor TiO2 / PPy / WO3 composite onto a conductive substrate. TiO2 / CN X / WO3's excellent sustained photocathode protection performance can be attributed to the highly conductive CN X In synergy with WO3, a narrow-bandgap semiconductor with energy storage properties, TiO2 nanoparticles with stable photoelectrochemical properties serve as the main material, ensuring the stability of the photoelectric performance of ternary materials.

The invention relates to a photoelectric signal extraction device and method, in particular to a low-time-dispersion strong-background photoelectric signal extraction device and method. The device comprises a photoelectric cathode, an accelerating electrode and an MCP detector, as well as an electron beam input guide tube, an electron beam guide tube, an electron beam buffer guide tube, a time dispersion compensation type electron beam guide tube and an electron beam output guide tube which are connected in sequence, the photoelectric cathode and the accelerating electrode are sequentially arranged at an inlet of the electron beam input guide tube; the electron beam guide tube and the time dispersion compensation type electron beam guide tube are respectively of a solenoid structure with a bent 1 / 4 spherical surface, and the other guide tubes are respectively of a straight cylindrical hollow solenoid structure; and the MCP detector is arranged at the outlet of the electron beam output guide tube. Spatial separation of detection signals and gamma and strong neutron radiation backgrounds can be realized, the signal-to-noise ratio of the system is improved, the time resolution is improved, the input end face of the MCP detector is prevented from being radiated by strong neutrons, and the service life of the detection system is prolonged.

A high-gain photomultiplier tube and a method for manufacturing the same. The photomultiplier tube comprises an upper ceramic substrate and a lower ceramic substrate, with a photocathode, a grid, an anode, and a plurality of electron multipliers disposed between the two ceramic substrates. A metal conductive film is deposited on the surfaces of the upper and lower ceramic substrates opposite the electron multipliers, and the metal conductive film is in mechanical contact with each electron multiplier. The photocathode, grid, anode, and electron multipliers are each connected and fixed to the ceramic substrate via positioning pins. A voltage divider resistor is connected between the photocathode and the positioning pin of the first-stage electron multiplier, between the positioning pins of two adjacent electron multipliers, and between the positioning pin of the last-stage electron multiplier and ground. The potential of each electron multiplier is set by adjusting the voltage divider resistor, and the potential difference between two adjacent electron multipliers and the potential difference between the last-stage electron multiplier and ground is in the form of a differentiated voltage divider. The present invention improves the gain and lifespan of the photomultiplier tube.

The present invention discloses a preparation method based on an integrated cuprous oxide photocathode. The method includes the preparation of a protein template, the step of preparing a hole transport layer on a conductive substrate, the formation of an inverse protein cuprous oxide photonic crystal structure, and the preparation of a protective layer. Its feature lies in that the step of preparing the photocathode based on the multiple modification of cuprous oxide photonic crystals includes: self-assembling a nanoscale protein template on the substrate with a hole transport layer, then electroplating cuprous oxide and a protective layer by an electrochemical method, and finally forming a multifunctional photocathode with an inverse protein photonic crystal structure through a high-temperature pyrolysis method or a solvent adsorption and desorption method. The multi-layer modified inverse protein Cu2O photocathode obtained by the present invention presents an ordered porous structure and exhibits the characteristics of a photonic crystal. By controlling the size of the protein template, the internal morphology of the inverse protein photonic crystal is regulated, and with the assistance of superimposing multi-layer functional thin films, three goals are achieved: a, improving the light capture ability of the material; b, increasing the photogenerated charge separation efficiency and accelerating the transfer of photogenerated electrons-holes from the bulk to prevent their self-oxidation; c, and avoiding the self-reduction of cuprous oxide through the presence of the protective layer. In the photo-electrochemical catalytic carbon dioxide reaction, the integrated Cu2O photocathode efficiently converts carbon dioxide into carbon monoxide (Φ STC = 1.6%, Yeild CO = 46.7 mmol / h).

The application discloses a micro-nano grating and photocathode collaborative design method. The method breaks the traditional isolated design, and considers the micro-nano grating and the photocathode as an organic whole, and takes the spectral response or integral quantum efficiency of the system as a whole as a target function. Specifically, the method comprises the following steps: establishing a system structure model and clearly defining an optimization target and process constraints; establishing a complex refractive index-wavelength correlation model of the photocathode to accurately obtain a complex refractive index distribution; determining a set of parameters to be optimized and setting initial values; calculating the system electric field distribution under the current parameters based on an electromagnetic simulation model; combining the electric field distribution and the photoelectric emission mechanism to calculate the spectral response of the system in the target waveband; and using a parameter optimization algorithm to iteratively search the parameter space, and outputting an optimal parameter combination. The application fully considers the electromagnetic and photoelectric coupling between the two and the actual process constraints, has the advantages of high design accuracy, strong pertinence, good implementability and the like, and can significantly improve the detection sensitivity of a weak light detection device.

An embodiment of the present disclosure provides a pulse electron microscope device including: a pulse generator configured to emit a laser pulse; a first beam splitter configured to split the laser pulse into a first laser pulse and a second laser pulse; a second beam splitter configured to split the second laser pulse and to reflect a second-1 laser pulse; an interval controller configured to control a time interval between the first laser pulse and the second-1 laser pulse by controlling an optical path length of the first laser pulse; a column part including a photocathode, the photocathode configured to convert the first laser pulse into a first electron pulse and convert the second-1 laser pulse into a second electron pulse; and an inspection module configured to inspect electrical defects in the sample by detecting a change in potential occurring on a surface of the sample.

The present application relates to the field of dehumidification, in particular to a photoelectrochemical auxiliary dehumidification device driven by shadow effect, the upper layer is super-hygroscopic hydrogel, the middle layer is photoelectrochemical cell, and the lower layer is shadow effect device; in the photoelectrochemical auxiliary dehumidification system provided by the present application, the moisture absorbed by the hydrogel is rapidly decomposed by the photoelectrochemical cell with enhanced voltage generated by the shadow effect device. The absorption of atmospheric moisture by the hydrogel and the voltage generated by the light contrast difference of the shadow effect device caused by the transparent photoanode of the photoelectrochemical cell from the upper layer and the light-tight photocathode result in continuous dehumidification of the closed space under zero energy input, the relative humidity in the room can be maintained below 70% without additional energy input, and a certain stable current is generated, which improves the efficiency of the dehumidification system and reduces energy consumption, and has wide application prospect.

Disclosed is an electron microscope system including a light generator including a modulator that modulates excitation light based on a control signal, an electron gun including a photocathode that generates an emission current as the modulated excitation light is radiated on the photocathode, wherein an amount of the generated emission current depends on the modulated excitation light, a sensor circuit that senses the emission current as the emission current is generated, and a control unit that generates the control signal based on an amount of a reference current and an amount of the sensed emission current.

The application belongs to the technical field of photon imaging detection, and particularly relates to a photon counting imaging detection system based on a mixed anode. The system comprises a vacuum sealed tube detector composed of a window coated with a photocathode, a microchannel plate stack and a mixed anode, and a signal processing circuit. The photocathode is used for converting photons incident through the window into photoelectrons. The microchannel plate stack is used for converting the photoelectrons into electron clouds. The mixed anode comprises a strip anode and a delay line anode arranged orthogonally, and the mixed anode transmits the collected charge short pulses of each channel to the signal processing circuit. The signal processing circuit calculates the two-dimensional coordinates of the photons based on the collected charge short pulses of each channel, and then transmits the two-dimensional coordinates of the photons to a terminal for imaging display. The application provides a photon counting imaging detection system based on a cross strip-delay line mixed anode, and solves the problem that the existing position sensitive anode detector cannot simultaneously have high spatial resolution and high temporal resolution.

The invention belongs to the technical field of photoelectrochemical water splitting photocathode material preparation, and particularly discloses a copper-based chalcogenide solar water photosplitting hydrogen production film photocathode and a preparation method thereof, the copper-based chalcogenide solar water photosplitting hydrogen production film photocathode comprises a Mo plated glass substrate, a copper-based chalcogenide film, a zinc tin oxide film, a TiO2 layer, a Pt layer and an Ag colloid electrode layer, and a gap is arranged between the Ag colloid electrode layer and the copper-based chalcogenide film. Compared with the prior art, the cadmium-free zinc tin oxide thin film is used as the electron transport layer, so that the cost is low, and the solar cell is environment-friendly and non-toxic; the thickness of the zinc tin oxide thin film is accurately regulated and controlled, so that the constructed copper-based chalcogenide / ZTO heterojunction energy band arrangement can present an ideal spike-like configuration, and the corresponding conduction band offset (namely the difference value between the conduction band bottom energy of the ZTO and the conduction band bottom energy of the copper-based chalcogenide) is 0-0.4 eV; accumulation and recombination of photon-generated carriers on an interface can be restrained in a limited mode, and efficient carrier transportation can be guaranteed.

The ultrafiltration membrane comprises a transparent membrane cylinder, membrane wires, an end cover, a water inlet and a water outlet, the cylinder wall of the transparent membrane cylinder is further provided with a concentrated water outlet and a sludge discharge port, the membrane wires are arranged in the transparent membrane cylinder, a plurality of low-light perspective devices are arranged on a cylinder body of the transparent membrane cylinder in a staggered mode, the low-light perspective devices extend into the transparent membrane cylinder, and the end cover is arranged on the end cover. The low-light perspective device comprises a transparent shell, a cesium photocathode is arranged at the front end in the transparent shell, the cesium photocathode is connected with the near-infrared light image converter tube, and the tail end of the transparent shell is connected with a hole in the cylinder wall of the transparent film cylinder in an embedded mode. According to the utility model, the transparent membrane cylinder of the ultrafiltration membrane is visual and is assisted by the low-light perspective device, so that not only can the pollutant concentration and pollutant accumulation condition of the existing ultrafiltration system be directly visualized, but also the pollution degree of the membrane silk can be clearly known by using the low-light perspective device.

The application provides an X-ray communication device and method based on a laser-driven matrix photocathode. The device is applied to the technical field of X-ray tubes and comprises a laser control circuit, a matrix transmission photocathode array, a collimating microchannel plate, a matrix transmission anode target array, a vacuum tube shell and a beryllium window. The method comprises: generating a dynamic pattern, loading data information to be input into an optical signal; and exciting photoelectron emission with spatial resolution characteristics at a corresponding photocathode pixel area; each channel cluster is aligned with a single photocathode pixel at the front end; after the electrons enter the microchannel, continuous secondary electron emission occurs under the action of the electric field on the inner wall of the channel, and an avalanche effect is generated; and through mechanisms such as bremsstrahlung radiation, a bundle of microfocus X-rays is generated at each target point. In this way, the technical problems of the X-ray source in the prior art, such as the limitation in spatial coding capability, response speed, integration degree and communication dimension, can be solved.

The invention discloses a vacuum and solid integrated lightweight digital solar blind ultraviolet device, which comprises a glass input window, an ultraviolet photocathode, a microchannel plate, a digital readout circuit chip and a ceramic tube shell, the ultraviolet photocathode is attached to the front surface of the glass input window; the ultraviolet photocathode, the micro-channel plate and the digital readout circuit chip are arranged in a vacuum chamber of the ceramic tube shell; the micro-channel plate is positioned right below the ultraviolet photocathode; the digital readout circuit chip is located right below the micro-channel plate, and the device adopts a proximity packaging structure. The device is a high-resolution, integrated and lightweight vacuum digital solar blind device, does not need coupling, is integrated, realizes image digital output, is convenient to use and signal transmission, and is safe and reliable to use.

The application discloses a molybdenum monatomic anchored gamma-Fe2O3 photoelectric cathode catalyst, a preparation method of an electrode thereof and application of the catalyst to photoelectrocatalytic degradation of pollutants in water bodies. The molybdenum monatomic anchored gamma-Fe2O3 photoelectric cathode catalyst comprises a gamma-Fe2O3 carrier and molybdenum atoms anchored on the surface of the gamma-Fe2O3 carrier in the form of monatomic atoms, wherein the molybdenum atoms are anchored by replacing part of iron sites in the gamma-Fe2O3 crystal lattice. The preparation method comprises the following steps: mixing and impregnating a molybdenum precursor solution with gamma-Fe2O3, and evaporating dry; and performing twice calcination on the obtained solid to obtain the molybdenum monatomic anchored gamma-Fe2O3 photoelectric cathode catalyst; in the twice calcination, the first time calcination is performed at 250-350 DEG C in an oxygen-containing atmosphere, and the second time calcination is performed at 450-550 DEG C in an inert atmosphere.

The application provides a photomultiplier tube and a detector. The photomultiplier tube comprises: a photocathode configured to receive photons and emit photoelectrons based on the received photons; a photomultiplication system located downstream of the photocathode and arranged around a target axis, the target axis coinciding with or being parallel to a central axis of the photomultiplier tube, the photomultiplication system configured to receive the photoelectrons emitted by the photocathode and multiply the photoelectrons; and an anode configured to collect the photoelectrons multiplied by the photomultiplication system and output an anode current based on the collected photoelectrons. According to the embodiments of the application, the carrying capacity of each stage of the multiplication electrode is increased, thereby improving the pulse width response range of the photomultiplier tube and the linear current of the photomultiplier tube.

The invention provides an X-ray communication device and method based on a laser driving matrix type photocathode. The device is applied to the technical field of X-ray tubes and comprises a laser control circuit, a matrix transmission type photocathode array, a collimation type structure micro-channel plate, a matrix transmission type anode target array, a vacuum tube shell and a beryllium window. The method comprises the following steps: generating a dynamic pattern, and loading data information to be input into an optical signal; photoelectron emission with spatial resolution characteristics is excited in a corresponding photocathode pixel area; each channel cluster is aligned with a single photocathode pixel at the front end; after the electrons enter the micro-channel, continuous secondary electron emission occurs under the action of an electric field on the inner wall of the channel, and an avalanche effect is generated; a beam of micro-focus X-rays is generated at each target spot through mechanisms such as tough-induced radiation. In this way, the technical problem that in the prior art, an X-ray source is limited in space coding capacity, response speed, integration degree and communication dimension can be solved.

The invention belongs to the technical field of photoelectrocatalysis, and particularly relates to a preparation method of a double-confinement hollow photocathode and application of the double-confinement hollow photocathode in synthesis of ammonia from nitrate wastewater through photoelectric reduction. According to the method, based on an ion exchange and in-situ growth strategy, a FeMnO3 / CuFe2O4 / Ti hollow cube integrated photocathode is constructed, hydroxyl functionalized ionic liquid (OH-ILs) is further introduced through vacuum impregnation, and an ILs (at) FeMnO3 / CuFe2O4 / Ti nanoreactor with a dual confinement effect is formed. Under ultraviolet-visible-near infrared (UV-Vis-NIR) illumination, the photocathode can remarkably promote separation of photo-induced electron-hole pairs, the charge transfer efficiency is improved, and high-selectivity and high-efficiency ammonia synthesis is achieved. Experiments show that the photocathode can almost completely convert nitrate in high-concentration nitrate wastewater (50mM) within 2.5 hours, so that the effluent reaches the drinking water standard of the World Health Organization (WHO). In a flowing electrolytic tank, the ammonia yield reaches 20.51 mg h <-1 > cm <-2 >, the Faraday efficiency reaches up to 97.75%, and excellent catalytic performance is shown.

This photomultiplier tube includes a photoelectric surface, N-stage dynodes (N is an integer of 2 or more) for multiplying electrons emitted from the photoelectric surface, and an anode for collecting electrons multiplied by the dynodes. The anode has an electron collection surface that faces a secondary electron emission surface of the N-th stage dynode and at least partially extends along the secondary electron emission surface, and there is no electron passage hole on an electron path from the N-1th dynode to the N-th dynode.