360 degrees surround photon detector/electron multiplier with cylindrical photocathode defining an internal detection chamber
Patent 5656807 Issued on August 12, 1997. Estimated Expiration Date: 
September 22, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
September 22, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2141322 2160798 2234801 3188468 3260876 3415990 3859528 Scintillation spectrometer Data analyzing system having provision for optimizing counting conditions and thus improving statistical counting validity for enabling accurate computation of sample activity levels in liquid scintillation spectrometry Low intensity X-ray and gamma-ray imaging device InventorApplicationNo. 532155 filed on 09/22/1995US Classes:250/214VT, Vacuum tube type313/103R, Secondary emitter type (e.g., electron multiplier)313/105R, Three or more313/534Channel or circular typeExaminersPrimary: Westin, Edward P.Assistant: Lee, John D. Attorney, Agent or FirmForeign Patent References
International ClassH01J 043/00AbstractA 360° surround photon detector/electron multiplier having: i) a continuous annular inner wall formed of thin light-transmissive material defining an internal coaxial detection chamber; ii) an annular enclosed evacuated envelope integral with the inner wall; iii) a cylindrical photocathode positioned adjacent the vacuum side of the inner wall; and iv), an electron multiplier assembly housed within the envelope for multiplying photoelectrons emitted from the photocathode and operable as a plurality of adjacent, circumferentially arrayed electron multipliers, each including an output terminal. The outputs originating from various segments of the photocathode may be utilized with coincidence circuitry requiring simultaneous detection of light events in at least two different sections of the photocathode in order to eliminate spurious signals such as result from thermal electron emissions from the photocathode. The outputs may also be utilized to facilitate use in spectroscopic analysis, differentiating portions of the spectrum of light reaching the photocathode through an optional composite cylindrical array of adjacent light filters, each having different wavelength bandpass characteristics, which may be aligned with the electron multiplier sections and positioned within the detection chamber in close proximity to, and surrounded by, the inner wall of the envelope. Where possible, light-emitting sources or samples are placed within the detection chamber. Optionally, a reflector is positioned coaxially within the detection chamber to facilitate detection of light emanating from sources outside the detection chamber--e.g., i) external scintillation or luminescent samples, etc.; or ii), astronomical or other external light sources requiring collimators, microscopes, telescopes or the like.Other References
Field of SearchVacuum tube typeElectron multiplier Plural chambers or three or more electrodes Including a radiant energy responsive gas discharge device Channel multiplier Three or more Plural secondary emissive electrodes Channel multiplier Secondary emitter type (e.g., electron multiplier) With envelope Photocathode Having photocathode on tube wall Channel or circular type Having plural dynodes Photomultiplier With electron multiplier PHOTOSENSITIVE | |
