54 results about "Electron multiplier" patented technology

The present invention belongs to the technical field of electron multipliers, and relates to a rotary multi-stage separated dynode multiplication structure, which includes a turntable, a plurality of rotary dynodes, and a fixed dynode arranged outside the turntable; the fixed dynode includes a first cathode plate, a grid, a first upper baffle connected to the upper end of the first cathode plate, and a first lower baffle connected to the lower end of the first cathode plate. The first cathode plate is an arc-shaped plate, and the grid is connected to the side of the first cathode plate; the rotary dynode includes a second cathode plate, a second upper baffle, and a second lower baffle. The second cathode plate has the same shape as the first cathode plate, and both the second upper baffle and the second lower baffle are leaf-shaped plates; the plurality of rotary dynodes includes N working dynodes and a spare dynode, and the turntable is connected with a rotating device. The spare dynode can replace the dynode with deteriorated performance, thereby prolonging the service life of the electron multiplier. By rotation, the problem of too rapid deterioration of the performance of the first-stage and last-stage dynodes can be solved, and the gain of the electron multiplier can be improved.

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 invention discloses a method for simply and rapidly installing a dynode of an electron multiplier, and belongs to the field of electron multiplier assembly. According to the method, extra tools are not needed, and only three long screws and a pair of pointed tweezers need to be additionally used. According to the method, the problem that time and labor are wasted when the ceramic plate of the multiplier and nine dynodes are folded and aligned is solved, and the installation of the dynodes can be effectively accelerated. During installation, the three long screws are inserted into the through holes of the ceramic plate bottom plate, then the screws are sleeved with the limiting stainless steel cylinders respectively, then the nine dynodes and the collecting plate are sequentially installed on the ceramic plate bottom plate, then the ceramic plate top plate is sleeved with the three screws, the hexagonal studs are screwed, and the ceramic plate top plate is installed on the ceramic plate bottom plate. And the distance between the top and bottom ceramic plates is about 4mm longer than that of the limiting stainless steel cylinder. The nine dynodes and the collecting plate are sequentially stirred through pointed tweezers, the upper feet of the dynodes and the collecting plate enter the small mounting holes corresponding to the top plate of the ceramic plate, the lower feet of the dynodes do not leave the small mounting holes corresponding to the bottom ceramic plate, and the top ceramic plate and the bottom ceramic plate are tightened after completion. And the long screws are replaced by the original screws of the multiplier in sequence, and the dynode is assembled.

The invention belongs to the technical field of vacuum electronic devices, and particularly relates to a dynode with an edge expansion type inner substrate and an electron multiplier comprising the dynode. The dynode comprises a grid mesh assembly, a base frame box and an edge expansion type inner substrate, and the inner substrate is located in the base frame box. The lining bottom comprises an arc-shaped side wall part, an upper wall, a lower wall and a bent part; the bent parts are arranged between the arc-shaped side wall part and the upper wall and between the arc-shaped side wall and the lower wall; the base frame box comprises a side wall, and an upper baffle and a lower baffle which are connected with the side wall; the arc-shaped side wall part of the lining bottom is attached to the side wall of the base frame box, the upper wall of the lining bottom is tightly attached to the upper baffle of the base frame box, and the lower wall of the lining bottom is tightly attached to the lower baffle of the base frame box. The inner substrate structure enables the electric field in the dynode to change, and especially the electric field intensity at the corners in the dynode, namely the area where the bent part is located, is obviously changed. The problem of low dynode electron collection efficiency is solved, and the gain of the electron multiplier is improved.

An electron tube is provided in which electrons emitted from an electron emitting section can be reliably made to reach an electron multiplier section, and the electrons can be reliably multiplied in the electron multiplier section. [Solution] The electron tube (1) comprises an electron emitter (3) including a metasurface (32) that emits electrons in response to incidence of electromagnetic waves (W), an electron multiplier (4) that multiplies the electrons emitted from the electron emitter (3), and a first mesh electrode (5) arranged between the electron emitter (3) and the electron multiplier (4). The electron multiplier (4) has an electron incidence region (4a) onto which the electrons emitted from the electron emitter (3) are incident. The distance α between the metasurface (32) and the electron incidence region (4a) is smaller than the width β of the electron incidence region (4a).

The embodiment of the invention provides a wide dynamic range ion pulse threshold adaptive counting method and circuit, and the method comprises the steps: a first end of an electron multiplier is connected with an ion signal, a second end is connected with an input end of an amplification circuit, an output end is connected with a first end of a baseline extraction module, and a second end is connected with a first end of a baseline smoothing module; the second end is connected with the input end of the comparison circuit and the output end is connected with the counting circuit; the electron multiplier is used for converting the ion signal into a current pulse; the amplifying circuit is used for converting the current pulse into a voltage pulse; the baseline extraction module is used for extracting a voltage pulse baseline to obtain a baseline signal; the baseline smoothing module is used for smoothing the baseline signal to obtain a smoothed signal; the comparison circuit is used for dynamically determining a self-adaptive threshold value based on the smooth signal, comparing the voltage pulse with the self-adaptive threshold value and outputting a comparison signal; and the counting circuit is used for pulse counting to obtain the number of target pulses. Therefore, the counting accuracy and the counting upper limit are improved.

An illustrative method comprises determining, based on a mass analysis performed by an electron multiplier-based mass analyzer on a first ion population produced from a sample, a mass spectrum comprising one or more peaks representing intensity as a function of mass-to-charge ratio (m / z) of the first ion population across a range of m / z values; determining, based on the mass spectrum, a total ion count of the first ion population and a peak ion count associated with a peak located at a particular m / z value; determining, based on the total ion count of the first ion population and the peak ion count, a total ion count of a second ion population produced from the sample and injected into an image current-based mass analyzer for mass analysis; and setting, based on the total ion count of the second ion population, a calibration parameter for the image current-based mass analyzer.

The invention provides a dynamic zooming-based oblique sheet type light sheet microscopic imaging system, which comprises a light sheet generation unit used for generating a light sheet signal, the light sheet signal is incident to a high-speed galvanometer unit through a dichroscope, the high-speed galvanometer unit is used for carrying out angle adjustment on the light sheet signal and controlling the light sheet signal to carry out transverse scanning, and the light sheet generation unit is used for generating the light sheet signal; the first scanning lens and the liquid lens are used for controlling the light sheet signal modulated by the high-speed galvanometer unit to perform Z-direction scanning; the first objective lens is used for controlling the light sheet signal modulated by the liquid lens to obliquely enter a sample at a preset angle; the first objective lens, the liquid lens and the first scanning lens are further used for modulating an excitation light signal of a sample, the dichroscope is further used for sending the modulated excitation light signal to the imaging unit, and the synchronous control unit is used for controlling the high-speed galvanometer unit, the first scanning lens, the liquid lens and the electron multiplication charge coupler to work synchronously. The imaging system provided by the embodiment of the invention is easy to integrate, high in resolution and high in imaging speed.

The invention relates to the technical field of vacuum measuring instruments, in particular to an fA-level tiny signal amplifier for a four-level mass spectrometer, which comprises a positive ion signal processing system, an electronic signal processing system, a signal acquisition module and an isolation module, wherein the positive ion signal processing system comprises a positive ion I-V conversion module and a positive ion signal conditioning module, and the positive ion I-V conversion module is connected with the positive ion signal conditioning module; the electronic signal processing system comprises an electronic I-V conversion module and an electronic signal conditioning module, and the electronic I-V conversion module is connected with the electronic signal conditioning module; the positive ion signal conditioning module and the electronic signal conditioning module are both connected with the signal acquisition module; the signal acquisition module is connected with the isolation module. The quadrupole mass spectrometer can directly and effectively amplify and collect positive ion signals at the Faraday cup end of the quadrupole mass spectrometer and electronic signals at the electron multiplier end, and measurement of positive ions in the range of 1 * 10 <-14 > A to 1 * 10 <-8 > A and electrons in the range of 1 * 10 <-12 > A to 1 * 10 <-6 > A is achieved.

The invention discloses a small-halo vacuum photoelectric device and application thereof. The small-halo vacuum photoelectric device comprises a first ceramic ring, a second ceramic ring, a first metal ring, a second metal ring, an elastic pressing ring and an electron multiplication plate with a conductive input surface and a conductive output surface, a first ceramic ring is arranged on the bottom surface of the first metal ring; a second metal ring is arranged on the bottom surface of the first ceramic ring; the second metal ring is arranged on the top surface of the second ceramic ring; an anode is arranged on the bottom surface of the second ceramic ring. By arranging an angle from 89 degrees to 86 degrees on the elastic compression ring of the structure device, plane contact between the elastic compression ring and the conductive input surface of the electron multiplication plate is realized, and local or complete non-electric contact between the elastic compression ring and the electron multiplication plate and related surfaces thereof is eliminated; the halo phenomenon generated by stray light generated by surface deformation of the electron multiplier plate is eliminated, and the imaging quality is improved.

The invention relates to calibration of a mirror current-based mass analyzer included in a mass spectrometer. An exemplary method includes determining a mass spectrum including one or more peaks representing an intensity as a function of m / z of a first ion population across a range of mass-to-charge ratio (m / z) values based on a mass analysis performed by an electron multiplier-based mass analyzer on the first ion population generated from a sample; determining a total ion count of the first ion population and a peak ion count associated with a peak located at a particular m / z value based on the mass spectrum; determining a total ion count of a second ion population generated from the sample and injected into a mirror current-based mass analyzer for mass analysis based on the total ion count of the first ion population and the peak ion count; and setting a calibration parameter for the mirror current-based mass analyzer based on the total ion count of the second ion population.

An electron tube used by being attached to an external device, including a housing having a light incident window including a light incident surface and allowing light from the external device to be incident thereon through the light incident surface, a photoelectric conversion portion disposed inside the housing to face the light incident window, and configured to emit electrons in response to the light incident from the light incident window, an electron multiplier portion disposed inside the housing and configured to multiply electrons emitted from the photoelectric conversion portion, and a positioning member formed separately from the light incident window and fixed to the light incident surface, the positioning member having a light passing portion passing the light from the external device toward the light incident surface, in which the positioning member has a reference portion serving as a reference for mechanical positioning with respect to the external device.

The invention provides a hierarchical control method and device for a residual gas analyzer and a medium, and the method comprises the steps: receiving a starting instruction sent by machine station equipment, and starting an ion source when the local vacuum degree is smaller than a first preset threshold value; when the total voltage is smaller than a second preset threshold value, an electron multiplier power supply is started; when the local vacuum degree and the total pressure are smaller than a third preset threshold value, a mass spectrometer power supply is started; receiving a vacuum breaking instruction sent by the station equipment, and disconnecting a functional module power supply of the residual gas analyzer; and receiving a power-off instruction sent by the station equipment, and when the local vacuum degree and the total pressure are greater than or equal to a second preset threshold value, cutting off the power supply of the electron multiplier, and when the local vacuum degree and the total pressure are greater than or equal to a first preset threshold value, disconnecting the ion source and the mass spectrometer power supply in sequence. The problem of hardware damage caused by out-of-control vacuum degree of the residual gas analyzer is solved through vacuum degree pre-judgment, graded protection and intelligent collaborative protection methods.

The present application relates to the field of pharmaceutical analysis, and more particularly to a method for simultaneously determining the contents of multiple components in Yinhu Ganmao Powder based on GC-MS technology, which comprises a method for simultaneously determining the contents of multiple components in Yinhu Ganmao Powder or volatile oil. The method comprises the following steps: (1) performing GC analysis on the extract of Yinhu Ganmao Powder or volatile oil; (2) performing mass spectrometry identification using a mass spectrometry library, with the mass spectrometry conditions being: ion source is electron impact ionization (EI), energy is 70 eV, ion source temperature is 200 DEG C, interface temperature is 250 DEG C, full scan mode is m / z 45-500, electron multiplier voltage is 1.5 kV, and collision gas is argon (99.99%). The present application establishes a method for simultaneously determining the contents of multiple components in Yinhu Ganmao Powder or volatile oil based on GC-MS technology, wherein more than 50 compounds are identified in the volatile oil of Yinhu Ganmao Powder, and more than 25 compounds are identified in the n-hexane extract of the powder.

A method for determining a performance parameter of an electron multiplier (e.g. parameter indicative of gain) comprises comparing an electron flux of a first electron emissive surface with an electron flux of a second electron emissive surface, or of an electron collector. The electron emissive surfaces form part of an electron multiplication chain, and may be discrete dynodes or provided by a single electron emission surface (e.g. a channel of a channel electron multiplier, or a plate of a microchannel plate electron multiplier). The first electron emissive surface may be earlier in the chain and less susceptible to electron flux-mediated gain degradation. A current ratio from the two electron emissive surfaces may be determined and compared with a comparator. An operating parameter (e.g. voltage bias) of the electron multiplier may be altered based on the determined performance parameter or current ratio. The invention may obviate or reduces the need for manual gain adjustment by adjusting the gain continuously and automatically to account for gain instability based on the comparison.

The invention belongs to the technical field of electron multipliers, and relates to a bowl-shaped dynode multiplication structure and an electron multiplier comprising the same. The dynode multiplication structure is integrally of a bowl-shaped structure and specifically comprises an A-type dynode located in the middle and a B-type dynode located on the periphery of the A-type dynode by a circle. The A-type dynode comprises a circular substrate, a cone-like body is arranged on the circular substrate, the B-type dynode comprises a fan-shaped cone, and secondary electron emission films are attached to the arc-shaped surface of the cone-like body and the arc-shaped inner surface of the fan-shaped cone. The curved surface of the cone-like body is a smooth arc-shaped curved surface or a curved surface consisting of three sections of inclined surfaces with different slopes; and the curved surface of the fan-shaped cone is a smooth arc-shaped curved surface or a curved surface consisting of three sections of inclined surfaces with different slopes. By adopting the bowl-shaped structure, the electron receiving rate of the first-stage dynode can be improved, and the gain of the electron multiplier can be improved; under the structure, electrons have a larger bombardable area, the loss of the secondary electron emission film is reduced, and the service life of the multiplier is prolonged.

To provide an electron multiplier tube with an improved structure.SOLUTION: The invention may be implemented in the form of a detector containing 11 or more electron emitting surfaces. A detector includes one or more detector components configured to define an environment inside the detector on one side and an environment outside the detector on the other side, and the one or more detector components are configured to restrict or prevent gas flow from an environment external to the detector to an environment internal to the detector. Such a detector can be used in a mass spectrometer.SELECTED DRAWING: Figure 5

The invention belongs to the field of mass spectrometry instruments, particularly relates to an ion receiving device, and aims to solve the problem of signal crosstalk among multiple channels of a combined receiver. The ion receiving device provided by the invention comprises a receiver body, and a signal detection cup unit, a slit sheet, a suppression gate unit, a Faraday cup unit and an electron multiplier unit which are mounted on the receiver body, the slit piece, the suppression gate unit and the Faraday cup unit are arranged along a first direction, and an ion beam sequentially passes through the slit piece, the receiver body and the suppression gate unit and then enters the Faraday cup unit; the signal detection cup unit, the Faraday cup unit and the electron multiplier unit are arranged at intervals along a second direction, and the second direction is perpendicular to the first direction. According to the ion receiving device provided by the invention, the signal detection cup unit, the Faraday cup unit and the electron multiplier unit are arranged at intervals along the direction perpendicular to the incident direction of the ion beam, so that signal crosstalk among channels is avoided.

The application provides an electronic detector and an electronic detection system. The electronic detector comprises: a Faraday cage for collecting secondary electrons; an electron multiplier fixed to a shielding outer cylinder, for performing primary amplification of the secondary electrons based on a first voltage at an input end of the electron multiplier and a second voltage at an output end of the electron multiplier; a power supply ring connected to the input end of the electron multiplier and the output end of the electron multiplier respectively, for providing the first voltage to the input end of the electron multiplier and the second voltage to the output end of the electron multiplier; a semiconductor detector fixed to the shielding outer cylinder, for applying a third voltage and a bias voltage to the secondary electrons to convert the secondary electrons into a current signal after performing secondary amplification; an amplifier circuit connected to the semiconductor detector, for converting the current signal into a voltage signal; and a signal amplification processing circuit, for converting an image signal from the voltage signal after amplification, so that the electronic detection efficiency can be improved and the image signal-to-noise ratio can be enhanced.

The utility model provides a trans-impedance amplifier-based gain self-adjusting ion signal detection circuit, comprising an electron multiplier CEM which converts an ion signal into an electron beam and transmits the electron beam to a low-gain signal amplification circuit and a high-gain signal amplification circuit through a trans-impedance amplifier U1. The output amplitude recognition and transmission circuit is used for judging the amplitude output by the low-gain signal amplification circuit and the high-gain signal amplification circuit and transmitting a signal generated after comparison to the control unit through an ADC, and the control unit controls the I / V conversion resistance adjustable circuit to switch the resistance value of the transimpedance amplifier U1 according to the collected signal. And transmitting to a PC end to form a mass spectrum. According to the gain self-adjusting ion signal detection circuit based on the trans-impedance amplifier, the accuracy and the applicability of mass spectrum detection are improved; meanwhile, the problem of mass spectrum peak shape abnormity caused by large change of the concentration range of the sample to be detected is solved.

The invention discloses an ultraviolet light electron spectrometer which comprises a vacuum cavity and a magnetic shielding layer. A barrel lens type electron energy analyzer is arranged in the magnetic shielding layer, and the barrel lens type electron energy analyzer comprises a lens system and an electron multiplication detector; the lens system comprises two coaxially arranged annular lenses, a uniform annular channel is formed between the two annular lenses, and an ultraviolet light beam incidence channel is formed in the middle of the annular lens on the inner side; the electron multiplication detector is arranged on the upper portion of the inner side face of the inner side annular lens. The ultraviolet light source is arranged at the top of the ultraviolet light beam incidence channel; the sample table is arranged at the bottom of the ultraviolet light beam incidence channel and is arranged opposite to the ultraviolet light source emitting end; according to the invention, the ultraviolet light beam is combined with the barrel lens type electron energy analyzer, so that the miniaturization of the ultraviolet light electron energy spectrometer is realized.

The CEM and ion detector of the present embodiment has a configuration for achieving ion detection with higher sensitivity than the prior art. The channel-type electron multiplier has at least a channel body, an input-side conductive layer, an output-side conductive layer, and an electrode. The channel body contains a channel having a tapered opening portion provided on the input side, and a resistance layer and an electron emission layer formed on the inner wall surface of the channel. The input-side conductive layer is provided on the input end surface of the channel body and a part thereof extends within the tapered opening portion. The output-side conductive layer is provided on the output end surface of the tapered opening portion. The electrode has one or more openings through which charged particles pass, and is disposed on the opposite side of the output end surface with respect to the input end surface. The electrode and the input-side conductive layer are set to the same potential by excluding the influence of an external electric field within the tapered opening portion.

To provide a method for determining performance parameters of an electron multiplier having a series of electron emission surfaces forming an electron multiplication chain.SOLUTION: The method includes the step of: comparing a first electron beam of a first electron emission surface of the electron multiplication chain with a second electron beam of a second electron emission surface of the electron multiplication chain or with a second electron beam of an electron collector of the electron multiplier.SELECTED DRAWING: Figure 1

The invention discloses a high-helix multichannel electron multiplier and a preparation method thereof, which are suitable for weak signal detection systems in high-end analytical instruments such as an Auger electron spectrometer (AES), an X-ray photoelectron spectrometer (XPS), a scanning electron microscope (SEM), a mass spectrometer and the like so as to meet the urgent requirements of the high-end analytical instruments on detectors with high sensitivity, low noise and long service life.

An ion detector includes a conversion dynode including a conversion region where electrons are emitted by incident ions, an electron multiplier including an electron incident surface on which the electrons are incident, and an aperture electrode including an aperture through which the electrons traveling from the conversion region to the electron incident surface pass. The conversion region is a region protruding toward a space where the electrons are emitted.

Provided is a photomultiplier tube including: a container including a window portion formed of a light-transmitting material, and a tubular portion that is connected to the window portion and defines a vacuum space in combination with the window portion; a photoelectric surface that is formed of a photoelectron-emitting material consisting of sodium, potassium, and antimony, is provided on a first surface of the window portion on a side of the vacuum space, and emits photoelectrons in correspondence with incident light; and an electron multiplier that emits secondary electrons in correspondence with incidence of the photoelectrons emitted from the photoelectric surface, and multiplies the secondary electrons. An aluminum oxide layer is formed between the photoelectric surface and the window portion and on a surface of the tubular portion.

The invention discloses an electron two-dimensional spin detector and application thereof. The electron two-dimensional spin detector comprises a high-transmittance metal net, an electron spin screening film, an electron multiplier and an electron detector which are sequentially arranged in the electron movement direction. Magnetizing devices are arranged around the electron spin screening film in the circumferential direction in an array mode, and positive and negative polarization in multiple directions is achieved. The high-transmittance metal net, the electron spin screening film and the electron multiplier are respectively connected with a voltage source, the voltage is changed, and the voltage difference between the high-transmittance metal net and the electron spin screening film is changed. The electron two-dimensional spin detector designed by the invention is simple in structure, does not need a complex process of coating or surface treatment, can directly detect two-dimensional spin electrons, can be combined with a hemispherical energy analyzer, a time-flight electron energy analyzer and other electron energy analyzers, and meets more measurement scenes.

The invention relates to the technical field of high electron gain, and discloses an electron detector, which comprises a first isolation part, a second isolation part and an electron multiplier, the first isolation parts are arranged on the incident plane of the electron multiplier device at intervals, the second isolation parts are arranged on the emergent plane of the electron multiplier device at intervals, a closed space is formed based on the first isolation parts and the second isolation parts, the electron multiplier device is arranged in the closed space, and the electron multiplier device is arranged in the closed space. Both the first isolation part and the second isolation part transmit electrons; and an incident electron beam sequentially passes through the first isolation part, the electron multiplier and the second isolation part and then is output to a receiving electrode. The invention solves the problem that the electron multiplier in the prior art has high requirements on the environmental vacuum degree in storage, assembly, transportation and use.

To provide an electron tube that can appropriately make electromagnetic waves having a predetermined electric field oscillation direction incident on an electron emission section and can appropriately multiply electrons emitted from the electron emission section in response to the incidence of the electromagnetic waves having the predetermined electric field oscillation direction. [Solution] The electron tube (1) comprises an electron emitter (3) including a metasurface (32) that emits electrons in response to incidence of an electromagnetic wave (W) having a predetermined electric field oscillation direction (V), an electron multiplier (4) that multiplies the electrons emitted from the electron emitter (3), and a first mesh electrode (5) arranged between the electron emitter (3) and the electron multiplier (4). The first mesh electrode (5) includes a plurality of wires (52) that define a plurality of openings aligned in a first direction (D1) parallel to the electric field oscillation direction (V). When viewed from the propagation direction (T) of the electromagnetic wave (W), each of the plurality of openings has an elongated shape whose longitudinal direction is a second direction (D2) that intersects with the first direction (D1) at an angle of 45 degrees or more.

This embodiment relates to an electron multiplier or the like having a structure for achieving faster response characteristics than conventional technologies. The electron multiplier comprises at least a dynode unit, a tube socket, a coaxial cable, a conductive member, and a capacitor. The dynode unit includes a multistage dynode, an anode, and a pair of insulating support members. The exposed portion of the inner conductor, which forms part of one end of the coaxial cable, is introduced into the dynode unit together with the end of the outer conductor. This structure allows the capacitor to be positioned in the space between the dynode unit and the tube socket, and the exposed portion of the inner conductor to be fixed to the portion of the anode held between the pair of insulating support members.