214 results about "Electron multiplication" patented technology

Methods and means for measuring and adjusting the gain of a photomultiplier tube (PMT), or other photo-detector with electron multiplication gain, for the purpose of achieving accurate light measurement, such as in a luminescent radiation dosimeter reader. With a PMT illuminated by a light emitting diode or other light source, the PMT output signal is measured in two modes, signal integration and photon pulse counting. The measured PMT gain is calculated as the ratio of the integrated signal to the photon pulse count. The PMT high voltage may be adjusted to cause the measured PMT gain to correspond to an established calibration gain value, or the data from the PMT may be adjusted to compensate the deviation of the measured PMT gain from the calibration gain value. The light source may be a controllable light source that can be adjusted to provide a specific photon count rate output as measured by the PMT. This invention provides for maintaining light measurement calibration without requiring temperature stabilization or a fixed light source.

An imaging system containing an electron-multiplying charge-coupled device detector and line-scan spectrograph is used for identifying wholesome and unwholesome freshly slaughtered chicken carcasses on high-speed commercial chicken processing lines. Multispectral imaging algorithms allow for real-time online identification of wholesome and unwholesome chicken carcasses.

When using a CCD sensor as a photo-detector in a device for inspecting foreign matters and defects, it has a problem of causing electric noise while converting the signal charge, produced inside by photoelectric conversion, into voltage and reading it. Therefore, the weak detected signal obtained by detecting reflected and scattered light from small foreign matters and defects is buried in the electric noise, which has been an obstacle in detecting small foreign matters and defects. In order to solve the above problem, according to the present invention, an electron multiplying CCD sensor is used as a photo-detector. The electron multiplying CCD sensor is capable of enlarging signals brought about by inputted light relatively to the electric noise by multiplying the electrons produced through photoelectric conversion and reading them. Accordingly, compared to a conventional CCD sensor, it can detect weaker light and, therefore, smaller foreign matters and defects.

This invention discloses novel nanocomposite material structures which are strong, highly conductive, and fatigue-resistant. It also discloses novel fabrication techniques to obtain such structures. The new nanocomposite materials comprise a high-conductivity base metal, such as copper, incorporating high-conductivity dispersoid particles that simultaneously minimize field enhancements, maintain good thermal conductivity, and enhance mechanical strength. The use of metal nanoparticles with electrical conductivity comparable to that of the base automatically removes the regions of higher RF field and enhanced current density. Additionally, conductive nanoparticles will reduce the surface's sensitivity to arc or sputtering damage. If the surface is sputtered away to uncover the nanoparticles, their properties will not be dramatically different from the base surface. Most importantly, the secondary electron emission coefficients of all materials in the nanocomposite are small and close to unity, whereas the previously used insulating particles can produce significant and undesirable electron multiplication.

A method for driving a solid-state imaging device including a plurality of pixels arranged in a two-dimensional array, each of the plurality of pixels accumulating a signal charge according to an amount of incident light, is provided. The method includes: performing electron multiplication of a first signal charge at a first multiplication factor to output a first image signal; and performing electron multiplication of a second signal charge at a second multiplication factor to output a second image signal, at least the first and second image signals being image signals of the same scene of a subject and being successively output.

The invention provides a novel series-parallel connection mass spectrum device system. The system comprises mass spectrum necessary basic subsystems, such as a set of quadrupole mass filter system, a special quadrupole rod/linear ion trap mass analyzer system, an ion guidance system, a quadrupole deflector, a hyperbolic quadrupole rod mass analyzer and ion counter system, a low air pressure linear ion trap mass spectrometer and electron multiplier system, a flight time mass spectrum system, a multi-path gas flow control system, a vacuum gauge, a multi-section differential motion vacuum system and the like. Furthermore, the invention provides a method for operating above systems to perform quantitative analysis in a triplet quadrupole rod mode, qualitative analysis in a quadrupole filtering medium combined high/low air pressure ion trap mode, and quick/high-mass precision analysis in a quadrupole filtering combined flight time mass spectrum mode on ultra-trace materials in a complex matrix, a method for utilizing an effective combination of three different mass analyzers to achieve optimal ion optical parameter adjustment and a method for performing high-precision qualitative and quantitative analysis on the ultra-trace materials.

Electron focussing apparatus includes a cathode plate defining an impact surface on which particles impact, which surface has a finite probability of generating at least one electron for each impacting particle having predetermined characteristics. The apparatus also has an electron receiving element, and respective means for generating electrostatic and magnetic fields in a space extending from the impact surface to the electron receiving element. The means for generating the electrostatic and magnetic fields are configured whereby the E/B² ratio adjacent the electron receiving element is smaller than adjacent the impact surface, whereby to decrease the radius of curvature of the electron trajectories adjacent the electron receiving element relative to adjacent the impact surface and to thereby focus the electron trajectories in at least one dimension. In another aspect the electron receiving element is positioned and the means for generating the electrostatic and magnetic fields are configured to cause the electrons to deflect on average through greater than 180° before impacting the electron receiving element, whereby to focus, in at least one dimension, multiple electrons generated from any given area of the impact surface to a smaller area at the electron receiving element.

The invention provides a system for realizing signal driving of an EMCCD (Electron Multiplication Charge Couple Device) by a high-voltage operational amplifier, relating to a driving technology of a CCD (Charge Couple Device), and solving the problems which are difficult to realize by the existing driving method. In the invention, a high-speed and high-voltage driving signal is obtained by a gain-adjustable high-speed and high-voltage operational amplifying circuit and can be applied when the working frequency is high and the multiplier voltage is high; by directly adopting digital signal control, the circuit stability is high; by adopting a DC (Direct Current)-DC power supply for supplying power, the voltage of the power supply changes according to the amplitude change of an output signal, and the power consumption of the operational amplifier can be lowered when the amplitude of the output signal is lower; and a low-pass filter converts an amplitude-adjustable square wave generated by a digital-to-analog converter into a sine wave, and the sine wave is amplified by the high-speed and high-voltage operational amplifier so as to generate a high-speed and high-voltage driving signal. The amplitude of the output signal is changed through two paths of digital control signals so as to realize the digital control on the output signal, thereby ensuring that final high and low level values are in the allowable working range of the device.

The subject invention provides for a novel photomultiplier assembly, termed the Microstructure Photomultiplier Assembly (MPA), which enables the effective conversion of light signals (received at the front of the assembly) into readily-detectable electrical signals. The MPA comprises a photocathode (which converts light into electrons and which is located in front of or on the front surface of the assembly), followed by an electron-multiplying plate, or series of plates, each made from an insulating substrate which does not emit sufficient contaminants to poison the photocathode. Each plate is coated on the front and rear faces with a conductive layer. In addition, the front face of each plate is further coated with a layer of secondary electron-emissive material which, when struck by an incoming electron, can produce secondary electrons. Each plate is perforated with channels (with non-conducting walls) and the number and geometry of these channels is designed to promote the efficient transfer and acceleration of electrons through the channel, under an applied voltage differential across the plate(s). The number of plates placed in series is determined by the desired degree of electron multiplication. At the exit of the last plate, an anode is located to collect the electrons and generate an electrical signal that can be read by conventional electronics. The anode can be a simple anode or can be a position-sensitive anode. The spacing between the photocathode, the electron-multiplying plates, and the anode is selected to promote the efficient transfer and acceleration of electrons across the assembly, as well as to promote the efficient production of secondary electrons. The photocathode, electron-multiplying plate(s) and anode are all contained within a vacuum enclosure.

A backside-illuminated image sensor is disclosed having improved quantum efficiency (QE) in the near infrared wavelengths (NIR: 750-1100 nm) with minimal optical interference fringes produced by multiple reflected rays within the photosensitive Si region of the sensor, which may be a charge-coupled device, a complementary metal oxide sensor or an electron-multiplication sensor. The invention comprises a fringe suppression layer applied to the backside surface of the photosensitive Si region of a detector (Si substrate) whereby the fringe suppression layer functions in concert with the Si substrate to reduce the occurrence of interference fringes in the NIR while maintaining a high QE over a broad range of wavelengths (300-1100 nm). The combination of a fringe suppression layer applied to a Si substrate provides a new class of back illuminated solid state detectors for imaging.

The invention discloses a four-dimensional electronic shadow imaging device, comprising a Femtosecond laser light source, a laser frequency tripling device, a Femtosecond electron gun and an electronic attitude control system, an ultrahigh vacuum cavity, an electron multiplication system, an imaging acquisition system, a vacuum pump system, a sample operating system, an optical path regulation system, a shutter and a time synchronization system. The four-dimensional electronic shadow imaging device has the advantages of shingle-shot imaging, high time resolution, high sensitivity to electromagnetic field information, high signal-to-noise ratio and on the like, and can perform time and space four-dimensional shadow imaging for the plasma forming process, the photovoltaic process or other ultrafast processes in which the transient electromagnetic field participates observably. The four-dimensional electronic shadow imaging device can record the four-dimensional time-spatial revolution information of the transient electromagnetic field within a time scale from hundreds of picoseconds to nanosecond by an ultrahigh time resolution superior to one picosecond.

An electron multiplier detector includes cathode structure defining a plurality of spaced co-planar impact surface segments on which particles impact. These surface segments each have a finite probability of generating at least one electron for each impacting particle having predetermined characteristics. The detector further includes respective sets of electron multiplication dynode segments associated with the impact surface segments, the sets being arranged as substantially parallel arrays extending behind the impact surface segments, and respective means for generating electrostatic and magnetic fields in a space extending from the impact surface segments past the dynode segments, whereby respective streams of electrons cascade and multiply successively along the arrays of dynode segments. Collector structure is provided to receive and detect the streams of electrons downstream of the last dynode segments in the arrays.

The invention discloses a high-collecting-efficiency micro-channel plate, a micro-channel plate type photomultiplier and a preparation method thereof. The photomultiplier has a structure which can realize high gain, high collecting efficiency, good single photoelectron spectrum, and collecting efficiency uniformity. The photomultiplier disclosed by the invention comprises a glass ball shell, an electronic focusing barrel, a photocathode and a micro-channel plate electron multiplication system. A metal electrode surface of a first micro-channel plate in an electron incident direction of an electron multiplier of the micro-channel plate type photomultiplier disclosed by the invention and the inner wall surface of a channel are both covered with a thin film with a high secondary electron emission coefficient, so that effective multiplication of electrons can be realized and the high collecting efficiency and the collecting efficiency uniformity of the photomultiplier can be improved.

The invention discloses a plant growth condition monitoring device and method based on an unmanned aerial vehicle. A blue LED array is adopted in an image monitoring module to replace a laser to serve as a fluorescence excitation light source, so that the size and weight of the excitation light source are greatly reduced, and the plant growth condition monitoring device is suitable for being used in the low-load unmanned aerial vehicle; besides, an electron multiplication CCD unit is adopted to collect fluorescence dynamic images of plants at night, and thus both fluorescence two-dimensional distribution information of a whole shooting area and comprehensive fluorescence dynamic attenuation information can be obtained. According to the plant growth condition monitoring device and method, the unmanned aerial vehicle flies along a path planned in advance and hovers at a designated shooting site, meanwhile, the fluorescence dynamic images are shot, and the unmanned aerial vehicle returns automatically after flying along the path planned in advance. Leaf dark adaptation is not needed, and thus measurement time is shortened; besides, in-situ measurement of plants is achieved, and thus the physiological growing state of plants can be reflected more accurately.

A full metal sealed EMCCD(Electron Multiplication Charge Coupled Device) camera refrigeration dewar comprises a thermoelectric cooler(TEC), a cold finger, a CCD socket, an EMCCD, a window, an outer shell, a copper seal ring and a base. A full metal sealed vacuum cavity is formed by the window, the outer shell and the base, the window and the outer shell are welded through anode welding, the outer shell and the base are sealed through knife edge flanges, the TEC, the cold finger, the EMCCD and the like are placed in the vacuum cavity, and the TEC serves as a cold source of a system. The interior of the vacuum cavity is vacuated, heat exchange between the EMCCD and the external environment is reduced to the minimum though the vacuum environment in the cavity, and thus the refrigeration effect is guaranteed. The system is suitable for the field of EMCCD camera refrigeration.

The invention relates to a radio-frequency cavity exercising method of a high-current compact type editcyclotron. The method is mainly characterized in that a cavity is primarily exercised through long-cycle narrow pulses, and the range of a multi-electron multiplication effect generated voltage is judged; according to color changes of the surface of a radio-frequency cavity, a magnetic pole face or a panel of the editcyclotron in the process, a graphite material is brushed at corresponding positions so as to reduce the secondary electron emission coefficient of the region; afterwards, by means of closing a magnetic field of the editcyclotron, all multi-electron effect regions are exercised from low to high in sequence by using a continuous power increase method, when all the multi-electron effect regions are passed, power feed is tuned and maintained for a period of time to accelerate gas outlet on a surface, then, push power is reduced at fixed time interval, and all the multi-electron effect regions are exercised from high to low; and after the processes are repeated ten times, the power supply of the magnetic field is switched on, and the exercise of the radio-frequency cavity can be completed rapidly by using the same method.

The invention relates to a method for preparation of a micro channel in the process of preparing Micro Electro-Me-chanical Systems elements, belonging to the technical field of Micro Electro-Me-chanical Systems. The resistance silicon from n (100) can form a hole of about 1 micrometer in special condition in solution of a concentration of 40% of HF: C2H5OH=1: 1, with this layer as template to be corroded out a reverse pyramid depression by KOH or tetramethyl ammonium hydroxide or the similar solution, and with the cellular silicon corrosion technique, the micro channel is corroded. The micro channel sheet for night-vision device can be prepared by oxygenizing the micro channel structure. With the method, the minimum micro-channel diameter and the center distance of channel have a great improvement, the electron multiplication effect also is perfect, the treatment temperature of the micro channel plate can achieve to 1200Deg. C, and the secondary electron emission efficiency is highly improved.

The invention discloses an ionospheric photometer suitable for a micro/nano satellite platform, which comprises a hollow parabolic reflector, an MCP-type anti-vibration detector and a circuit board, wherein the reflector and the detector are sequentially arranged in the circuit board and light incident to a reflector plate is made to be gathered to the detector; the detector comprises a supportingframe and a BaF2 crystal window, a microchannel plate, a detector anode and a high voltage power supply in the frame; after the light passes through the BaF2 crystal window to filter stray light, photoelectric conversion and electron multiplication are carried out through the microchannel plate, and through the detector anode, multiplied charge cloud signals are received. The weight of the existing photometer is reduced from more than 5Kg to less than 1Kg, the volume is decreased by more than 50%, photon filter losses are reduced, the sensitivity of the instrument is increased by more than 30%, batch processing is facilitated, and the batch production cost is reduced.