Method and device for determining the personal dose in mixed neutron/photon fields

• US 7,208,743 B2
• Filed: 07/09/2002
• Issued: 04/24/2007
• Est. Priority Date: 07/09/2001
• Status: Active Grant

• Current Assignee: Bundesrepublik Deutschland Vertreten Durch DAS Bundesministerium FUER Wirtschaft und Technologie Dieses Vertreten Durch Den Praesidenten Der Physikalisch-Technischen Bundesantalt
• Original Assignee: Bundesrepublik Deutschland Vertreten Durch DAS Bundesministerium FUER Wirtschaft und Technologie Dieses Vertreten Durch Den Praesidenten Der Physikalisch-Technischen Bundesantalt
• Inventors: Luszik-Bhadra, Marlies, Wendt, Wilfried
• Primary Examiner(s): GAGLIARDI, ALBERT J
• Application Number:
  US10/483,222
• Publication Number:
  US 20040188677A1
• Time in Patent Office: 1,750 Days
• Field of Search: 250/390.03, 250/370.05
• US Class Current: 250/390.03
• CPC Class Codes: G01T 1/02 Dosimeters G01T1/15 takes precedence
• CPC Class Codes: G01T 1/24 with semiconductor detectors
• CPC Class Codes: G01T 3/08 with semiconductor detectors

Abstract

The invention relates to an instrument which uses an individual semi-conductive detector with special coverings as an essential sensor, and a method whereby the amplitude information of the signals from said semi-conductive detector are used to determine a person'"'"'s dose in mixed neutron/photon-fields. Said instrument is highly sensitive and has a low energy dependency. It is possible for the dose to be read directly, and to emit a warning if the dose limit is exceeded. The inventive method enables a compact person'"'"'s dose meter, which is immune to interference, to be produced with low power consumption.

Claims

1. An apparatus for determining a personal dose equivalent on a combined neutron/photon field, comprising:

a single semiconductor neutron and photon detector, constructed and arranged to detect neutrons and photons, and to output a corresponding pulse signal having an amplitude statistically representative of whether a neutron or photon is detected; and

a dose equivalent detector, constructed and arranged to receive said pulse signals and, based on a count of said pulse signals and the amplitudes of said pulse signals, to generate a total dose equivalent data representing a total dose of neutrons and a total dose of photons detected over the same given time period.

2. The apparatus of claim 1, wherein the semiconductor detector includes a silicon detector having a sensitive depleted layer, and wherein the thickness of said layer is between approximately 1 μ

m and 400 μ

m.

3. The apparatus of claim 1

wherein the semiconductor detector includes a silicon detector having a sensitive depleted layer, and wherein

neutron converters, constructed and arranged to convert thermal neutrons, and fast neutrons into emitted protons, is arranged in front of said sensitive depleted layer, and

wherein said neutron converters each include one or more materials having a ⁶Li and ¹⁰B content, for detecting the thermal neutrons, and a plastic containing hydrogen, for detecting the fast neutrons.

4. The apparatus of claim 3, further comprising a thermal neutron absorber, formed of materials including ⁶Li and ¹⁰B, surrounding said single semiconductor detector and neutron converters, constructed and arranged to reduce a thermal neutron sensitivity of said semiconductor counter and said neutron converter.