Gas-target neutron generation and applications

A single-cathode high-pressure high-resistance gaseous discharge neutron producing apparatus, comprising:

• a) a vacuum chamber,
• b) an anode electrode located within said vacuum chamber having an anode electrode surface,
• c) a cathode electrode located within said vacuum chamber, wherein the cathode is comprised of at least one surface that is semi-transparent to nuclear and atomic particles, wherein said at least one semi-transparent surface determines a preferred direction of particle motion that is generally perpendicular to said at least one surface, said at least one cathode surface defining an intra-cathode region whereby particles may penetrate the at least one semi-transparent surface and traverse the intra-cathode region, said cathode surfaces further being adjacent to an anode-cathode gap region lying between the anode electrode and cathode electrode surfaces,
• d) a gas orifice for controllably introducing fusible deuterium gas into the vacuum chamber, and a pump orifice for controllably evacuating said vacuum chamber, and
• e) a controller for regulating the operation of a high-pressure high-resistance gaseous discharge within the vacuum chamber, including a voltage supply for controllably applying a negative high-voltage to said cathode electrode relative to the anode electrode, and for controllably allowing the passage of current.

A method of producing neutrons in a chamber containing an anode electrode and a semi-transparent cathode electrode comprising the steps of;

• introducing a fusible gas into the vacuum chamber;
• creating a voltage differential between the cathode electrode and the anode electrode whereby a high-pressure high-resistance gaseous discharge forms primarily between the anode electrode and at least one semi-transparent surface of the cathode electrode and extends through openings of the semi-transparent cathode into an intra-cathode region defined by at least one surface of the cathode electrode, and whereby ions selected from the group consisting of deuterium ions and tritium ions of said discharge are accelerated by said voltage differential, with a substantial portion of said ions passing through the openings of the semi-transparent cathode surfaces;
• allowing a portion of said ions to undergo charge-exchange collisions with background gas particles to produce fast-neutral particles selected from the group consisting of deuterium particles and tritium particles, whereby a portion of said fast neutral particles pass through the openings of the semi-transparent cathode surfaces, and whereby said high-resistance gaseous discharge is sustained primarily through charged particle generation initiated by the ions and fast neutral particles;
• and
• generating neutrons from said high-pressure high-resistance gaseous discharge predominantly as a product of fusion collisions occurring between said ions and background gas particles and between said fast-neutral particles and background gas particles.

A double-cathode high-pressure high-resistance gaseous discharge neutron producing apparatus comprising:

• a vacuum chamber;
• an anode electrode located within said vacuum chamber;
• an electron-suppressor cathode electrode located within said vacuum chamber comprised of at least one semi-transparent surface that determines a predominant direction of particle motion generally perpendicular to said surface, said surface bordering an intra-cathode region bounded by surfaces of the electron-suppressor cathode electrode, and an anode-cathode gap region within the vacuum chamber between the anode electrode and the electron-suppressor cathode electrode, wherein openings in said at least one semi-transparent surface of the suppressor electrode allow ions and fast neutral particles within the chamber to pass into and out of the intra-cathode region;
• a leeching cathode electrode located within said intra-cathode region, having at least one semi-transparent surface having openings to allow nuclear and atomic particles to move through said surface, wherein a surface of the leeching cathode electrode borders a leeching-suppressor gap region lying between said leeching cathode electrode and said suppressor electrode surfaces, wherein openings in said semi-transparent surfaces of the leeching electrode allow the passage of nuclear and atomic particles through the leeching-suppressor gap region, and wherein a portion of the openings of the semi-transparent leeching electrode are aligned with a portion of openings of the semi-transparent suppressor electrode so as to provide particle paths through both the suppressor and leeching cathode electrodes, and wherein the openings in said semi-transparent surfaces of the leeching electrode are sufficiently large so to allow the passage of ions and fast neutral particles;
• a leeching electrode power supply for controllably applying a voltage to said leeching electrode relative to the anode, and for controlling an amount of power delivered to the leeching electrode
• a suppressor electrode power supply for controllably applying a voltage to said suppressor electrode relative to the anode, and for controlling the amount of power delivered to the suppressor electrode;
• and
• a gas orifice for controllably introducing fusible deuterium gas into the vacuum chamber, and a pump orifice for controllably evacuating said vacuum chamber.

A method of producing neutrons in a chamber containing an anode electrode, a semi-transparent suppressor cathode electrode and a semi-transparent leeching cathode comprising the steps of;

• introducing a fusible gas into the vacuum chamber;
• creating a voltage differential between the cathode electrodes and the anode electrode, and applying a high-voltage to the leeching cathode, and a bias voltage to the suppressor electrode relative to the leeching cathode, whereby a high-pressure high-resistance gaseous discharge forms primarily between the anode and semi-transparent suppressor surfaces and extends through the openings of the semi-transparent suppressor electrode surfaces, passing through the suppressor and leeching electrodes and an intra-cathode region defined by at least one surface of the cathode electrode, and whereby ions selected from the group consisting of deuterium ions and tritium ions of said gaseous discharge are accelerated by the voltage differential, with a substantial portion of said ions passing through the openings of the semi-transparent cathode surfaces;
• allowing a portion of said ions to undergo charge-exchange collisions with background gas particles to produce fast-neutral particles selected from the group consisting of deuterium particles and tritium particles, whereby a portion of said fast-neutral particles pass through the openings of the semi-transparent cathode surfaces, and whereby said high-pressure high-resistance gaseous discharge is sustained primarily through charged particle generation initiated by the ions and fast neutral particles;
• and
• generating neutrons from said high-pressure high-resistance gaseous discharge as a product of fusion collisions occurring between said ions and background gas particles and between said fast-neutral particles and background gas particles.

A security and contraband inspection system for detecting target substances within a subject item comprising:

• a gas-target neutron generator to provide neutrons for material analysis of the subject item;
• a portable exterior container with radiation shielding to protect an external worker environment and to minimize signal noise to the radiation detector;
• a conveyance mechanism to move the subject item past the neutron generator;
• a radiation detector situated proximally to the subject item to detect secondary radiation emitted by chemical elements within the subject item upon irradiation by the neutron source;
• and
• an analysis module to receive information from said detector, and to analyze said information to determine chemical elements and their concentrations within the subject item.

A self-contained portable system for environmental and soil analysis using neutron analysis techniques, comprising:

• a gas-target neutron generator system to controllably provide neutrons for the analysis of soil or other environmental media;
• a radiation detector situated proximally to the soil or environmental media for collecting secondary radiation caused by the impingement of neutron with the soil or environmental media;
• and
• a data acquisition system to receive information from said detector and to determine properties of the soil or environmental media based on the information from said detector.

A portable medical system for diagnostic imaging and radiation therapy, comprising:

• a gas-target neutron generator system to controllably provide neutrons for interaction with a patient;
• a moderator to control the neutron energy directed to the patient;
• a gamma radiation detector to detect secondary radiation emitted from neutron interaction within the patient;
• and
• a data acquisition system to receive information from said detector and to determine properties of the patient based on the information from said detector.