摘要:
An apparatus for amplifying an electron signal caused by the impact of a particle with an electron emissive surface. The apparatus includes: a first electron emissive surface configured to receive an input particle and thereby emit one or more secondary electrons, a series of second and subsequent electron emissive surfaces configured to form an amplified electron signal from the one or more secondary electrons emitted by the first electron emissive surface, and one or more power supplies configured to apply bias voltage(s) to one or more of the emissive surfaces. The bias voltage(s) is sufficient to form the amplified electron signal. The apparatus is configured such that the terminal electron emissive surface(s) of the series of second and subsequent electron emissive surfaces draw a higher electrical current than that of the remainder electron emissive surface(s). The apparatus may be used as part of detector in a mass spectrometer, for example.
摘要:
A light intensifier includes a semiconductor structure to multiply electrons and block stray particles (e.g., photons and/or ions). The semiconductor structure includes an electron multiplier region that is doped to generate a plurality of electrons for each electron that impinges a reception surface of the semiconductor structure, blocking regions that are doped to direct the plurality of electrons towards emissions areas of an emission surface of the semiconductor structure, and shielding regions that are doped to absorb stray particles that impinge the emission surface of the semiconductor structure.
摘要:
The present invention relates to an MCP unit or the like having a structure intended to achieve a desired time response characteristic, without depending on a limitation imposed by a channel diameter of MCP. The MCP unit comprises the MCP for releasing secondary electrons internally multiplied in response to incidence of charged particles, an anode arranged in a position where the secondary electrons reach, and an acceleration electrode arranged between the MCP and the anode. In particular, the acceleration electrode includes a plurality of openings which permit passing of the secondary electrons migrating from the MCP toward the anode. Further, the acceleration electrode is arranged such that the shortest distance B between the acceleration electrode and the anode is longer than the shortest distance A between the MCP and the acceleration electrode. Thus, an FWHM of a detected peak appearing in response to the incidence of the charged particles is remarkably shortened.
摘要:
A thin diamond electron beam amplifier. The illumination side of a thin diamond is illuminated by a seed electron beam creating electron-hole pairs in the diamond. A voltage potential provides an electric field between the illumination side of the diamond and an acceleration grid opposite the emission side of the diamond. Electrons released in the diamond are accelerated through the emission side of the diamond toward the acceleration grid creating an amplified electron beam. Preferred embodiments of the present invention are useful to provide flat panel displays and replacements for thermionic cathodes, cathode ray tubes, fast photodetectors and image intensifiers.
摘要:
A method of manufacturing a photomultiplier tube (10) comprising a tube body (20), a photocathode (30) and an electron multiplier element (40) destined to be placed at a small distance from the photocathode (30). According to the invention the tube (10) is provided with sliding means (50) of the electron multiplier (40) parallel to the axis (22) of the tube body (20), means (50) provided with abutments (53) situated in the proximity of the said window (31). The electron multiplier (40) is also provided with means (60) for the remote soldering of the electron multiplier to the said sliding means (50), and in a first step the electron multiplier (40) is placed at a sufficient distance from the window (31), then in a second step the constituents of the photocathode are evaporated by means of evaporators (70) placed at a distance from the window and, in a third step, the electron multiplier (40) is moved against the said abutments (53), while in a fourth step the electron multiplier (40) is maintained in position in the proximity of the photocathode (30) by remote soldering to the sliding means (50) with the aid of the remote soldering means (60).
摘要:
A photomultiplier tube comprises an evacuated envelope having a photoemissive cathode, a shield cup spaced from the cathode and an electron multiplier cage assembly abutting the shield cup. The cage assembly includes a pair of transversely spaced support plates having a plurality of support slots formed therethrough. Each of the support plates has a distal end and a proximal end, with the proximal ends being attached to the shield cup. A light shield is disposed between the distal end of the support plates. An anode and a plurality of dynodes, at least one of which has a field mesh attached thereto, are disposed between the support plates and attached thereto by end tabs. The end tabs extend from the side of the anode and the dynodes. The aforementioned shield cup includes flaps which establish a minimum transverse spacing between the proximal ends of the support plates. The light shield has a transverse dimension substantially equal to that of the flaps to establish a minimum transverse spacing between the distal end of the support plates. The flaps and the light shield thus act, in combination, to provide a uniform minimum transverse spacing between the support plates which is greater than the transverse dimension of the anode and the dynodes to prevent distortion of the field mesh. The tab ends of the dynode and the anode are bifurcated so that one portion of selected ones of the tab ends can be formed to secure the dynodes and the anode between the support plates.
摘要:
A detector for the detection of, for example, Cerenkov radiation includes an entrance screen (5) which may cover more than half of an envelope (1); the majority of the envelope is preferably spherical. A photo-electron detecting exit screen (11) is proportioned and arranged inside the envelope (1) so that a small decay time and a high sensitivity are achieved. A scintillant exit screen (11), which is mounted on an indentation (15) in the envelope (1), can thus produce, in conjunction with a photomultiplier tube (17) mounted inside the indentation (15), a photoelectric intensification by a factor 100.
摘要:
Output current hysteresis exhibited by a multiple-dynode photomultiplier detector is reduced by inactivating one or more of the dynodes by shorting to the detector anode, and operating the detector with the reduced number of active dynodes while retaining the anode as the output current supply terminal.
摘要:
The present invention describes an ion gun which is capable of producing relatively high density ion currents. The ion gun employs at least one capillary duct the surface of which is semiconducting and has secondary electron emission coefficient greater than one to generate ions from a source of an ionizable material and to accelerate the ions so generated.
摘要:
The specification describes a vacuum device utilizing the multipacting phenomenon in a special insulated-electrode microwave comb-line structure and functioning as a high speed, single pole, single throw, RF switch with the exception that in the off condition, power is absorbed in the device.