Alpha Particle Detection System Patents (Class 250/370.02)
  • Publication number: 20040200968
    Abstract: An &agr;-ray measuring apparatus is provided for accurately analyzing the energy of a trace of &agr;-rays emitted from a sample in a short time using semiconductor detectors which excel in energy resolution. The &agr;-ray measuring apparatus comprises an &agr;-ray detector including a plurality of semiconductor detectors, an adder for adding output signals from the respective semiconductor detectors, an anticoincidence counter for anticoincidently counting the output signals from the respective semiconductor detectors, and a peak analyzer for analyzing an energy distribution of the &agr;-rays based on an addition of the output signals from the semiconductor detectors which are not anticoincidently counted. Since the output signals from the plurality of semiconductor detectors are added to increase the area of a sample under measurement and also remove background noise, the &agr;-ray measuring apparatus can more accurately analyze the energy of the &agr;-rays while reducing a measuring time.
    Type: Application
    Filed: March 29, 2004
    Publication date: October 14, 2004
    Inventors: Toru Shibutani, Akihisa Kaihara
  • Patent number: 6774638
    Abstract: A highly sensitive charged particle measuring device capable of measuring low-level alpha rays comprises in a measurement chamber 7 provided with a sealable door 15, a test sample 2 and a semiconductor detector 1, a radiation measuring circuit 30 including a preamplifier 30c connected to the semiconductor detector 1, a linear amplifier 30d, and a pulse height analyzer 30e, a charged particle emission amount arithmetic unit 40 for performing the quantitative analysis of charged particles from its measurement, a display unit for displaying its analysis result, and further has an evacuation pipe line and a pure gas supply pipe line for performing supply and replacement of the pure gas in the measuring chamber 7.
    Type: Grant
    Filed: March 7, 2003
    Date of Patent: August 10, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Nobuyoshi Kogawa, Hiroshi Kitaguchi, Tetsuya Matsui, Akihisa Kaihara, Junichi Arita
  • Patent number: 6753469
    Abstract: A power source converts &agr;-particle energy into electricity by coulomb collision in doped diamond films. Alpha particle decay from curium-244 creates electron-hole pairs by freeing electrons and holes inside the crystal lattice in N- and P-doped diamond films. Ohmic contacts provide electrical connection to an electronic device. Due to the built-in electric field at the rectifying junction across the N- and P-doped diamond films, the free electrons are constrained to traveling in generally one direction. This one direction then supplies electrons in a manner similar to that of a battery. The radioactive curium layer may be disposed on diamond films for even distribution of &agr;-particle radiation. The resulting power source may be mounted on a diamond substrate that serves to insulate structures below the diamond substrate from &agr;-particle emission. Additional insulation or isolation may be provided in order to prevent damage from &agr;-particle collision.
    Type: Grant
    Filed: August 5, 2002
    Date of Patent: June 22, 2004
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Elizabeth A. Kolawa, Jagdishbhai U. Patel, Jean-Pierre Fleurial
  • Publication number: 20040061060
    Abstract: A memory array operates as an alpha particle detector. A predetermined state is stored in each memory storage location. The operating voltage of the memory array is established at a voltage where the stored values are relatively stable and not subject to change except as a result of alpha particle impingement. Impinging alpha particles are detected by the state changes they cause in the memory storage locations.
    Type: Application
    Filed: September 30, 2002
    Publication date: April 1, 2004
    Inventors: Paul Arthur Layman, Samir Chaudhry, James Gary Norman, J. Ross Thomson
  • Patent number: 6707045
    Abstract: A detector for ionising radiation comprises first (10) and second (12) diamond detector elements which are connected to a common contact (14). The two detector elements are of differing thickness and are optimised for the detection of different types of radiation, so that the detector simultaneously provides two output signals indicative of different kinds of radiation incident on the detector.
    Type: Grant
    Filed: July 5, 2001
    Date of Patent: March 16, 2004
    Inventors: Ricardo Simon Sussmann, Geoffrey Alan Scarsbrook, Andrew David Garry Stewart
  • Patent number: 6479825
    Abstract: A low-energy particle sensor includes current collection areas which take the form of diodes partially covering the substrate. In detection areas defined alongside the collection areas the small thickness of the material enables low-energy particles (in particular a particles or protons) to penetrate the substrate. The currents generated by particles forming electron-hole pairs in this substrate are collected by the diode regions and sent to a load circuit. Applications include sensors for detectors of products resulting from collisions brought about in particle physics research apparatus.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: November 12, 2002
    Assignee: CSEM Centre Suisse d'Electronique et de Microtechnique SA
    Inventor: Paul Weiss
  • Patent number: 6262420
    Abstract: An apparatus and method for detecting alpha particles in the presence of high activities of beta particles utilizing an alpha spectrometer. The apparatus of the present invention utilizes a magnetic field applied around the sample in an alpha spectrometer to deflect the beta particles from the sample prior to reaching the detector, thus permitting detection of low concentrations of alpha particles. In the method of the invention, the strength of magnetic field required to adequately deflect the beta particles and permit alpha particle detection is given by an algorithm that controls the field strength as a function of sample beta energy and the distance of the sample to the detector.
    Type: Grant
    Filed: April 16, 1999
    Date of Patent: July 17, 2001
    Assignee: Sandia Corporation
    Inventors: Amir H. Mohagheghi, Robert P. Reese