# US 9,297,914 B2 · Neutron detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,297,914 B2 - Document ID: US9297914B2 - Status: Granted - Kind: B2 - Application number: 13/842,904 - Filed: 2013-03-15 - Published: 2014-03-20 - Granted: 2016-03-29 - Earliest claimed: 2012-06-11 - Assignees: Nova Scientific, Inc. - Applicants: Nova Scientific, Inc. - Inventors: Jon. H. Chappell; W. Bruce Feller - Web page: https://patentgrep.com/patent/US9297914B2 ## CPC - G01T 3/00: Measuring neutron radiation (G01T5/00 takes precedence) - G01T 1/28: with secondary-emission detectors - G01T 3/08: with semiconductor detectors - G01T: MEASUREMENT OF NUCLEAR OR X-RADIATION (radiation analysis of materials, mass spectrometry G01N23/00; tubes for determining the presence, intensity, density or energy of radiation or particles H01J47/00) ## Abstract A method for detecting a neutron includes providing a first voltage to an input electrode of a microchannel plate, providing a second voltage to an output electrode of the microchannel plate, the second voltage being more positive than the first voltage, measuring a signal on the output electrode, and detecting a neutron based on a comparison of the signal at the output electrode with a baseline value. ## Claims ### Claim 1 A method for detecting a neutron, the method comprising: providing a first voltage to an input electrode of a microchannel plate; providing a second voltage to an output electrode of the microchannel plate, the second voltage being more positive than the first voltage to provide a high voltage direct current field between the input and output electrodes to accelerate electrons in channels of the microchannel plate; measuring a signal on the output electrode; and detecting a neutron based on a comparison of the signal at the output electrode with a baseline value. ### Claim 2 (depends on 1) The method of claim 1 in which detecting a neutron comprises determining that a neutron has been detected when the signal at the output electrode is negative for a period of time. ### Claim 3 (depends on 2) The method of claim 2 in which detecting a neutron comprises determining that a neutron has been detected when the amplitude of the signal at the output electrode is also above a predetermined threshold. ### Claim 4 (depends on 1) The method of claim 1 in which detecting a neutron comprises determining that a neutron has been detected when the signal at the output electrode is positive for a first period of time and negative for a second period of time. ### Claim 5 (depends on 1) The method of claim 1, comprising detecting an avalanche of secondary electrons reaching an anode of the microchannel plate, wherein detecting a neutron comprises determining that a neutron has been detected when, for a period of time after the avalanche of secondary electrons have been detected, the signal at the output electrode becomes negative. ### Claim 6 (depends on 1) The method of claim 1, comprising integrating the signal at the output electrode over a period of time to generate an integral, wherein detecting a neutron comprises detecting a neutron when the integral has a negative value. ### Claim 7 (depends on 1) The method of claim 1, comprising providing a third voltage to an anode associated with the microchannel plate, the third voltage being more positive than the second voltage, and measuring a signal at the anode, wherein detecting a neutron comprises detecting a neutron when, during a period of time, the signal at the output electrode has a polarity that is the same as the signal at the anode. ### Claim 8 (depends on 1) The method of claim 1 in which the microchannel plate has a structure between the input and output electrodes, the structure comprising a hydrogen-containing material. ### Claim 9 (depends on 8) The method of claim 8 in which the hydrogen-containing material comprises a polymer. ### Claim 10 (depends on 8) The method of claim 8 in which the hydrogen-containing material comprises plastic. ### Claim 11 (depends on 8) The method of claim 8 in which the hydrogen-containing material is doped with at least one of boron-10 or lithium-6. ### Claim 12 (depends on 8) The method of claim 8 in which the hydrogen-containing material defines microchannels, and a layer of neutron sensitive material is disposed on walls of the microchannels. ### Claim 13 (depends on 8) The method of claim 8 in which the neutron sensitive material comprises at least one of boron-10 or lithium-6. ### Claim 14 A method comprising: providing a first electrode, a second electrode, and a material disposed between the first and second electrodes, the material comprising a first component that is sensitive to neutrons and a second component that is sensitive to gamma rays; providing a first voltage to the first electrode; providing a second voltage to the second electrode, the second voltage being more positive than the first voltage to provide a high voltage direct current field between the first and second electrodes to accelerate electrons between the first and second electrodes; discriminating between a neutron and a gamma ray by using a signal on the second electrode, the signal being influenced by moving charged particles generated as a result of an interaction between an incident particle or radiation and the material disposed between the first and second electrodes; and generating a detection signal indicating that a neutron has been detected when the signal on the second electrode is negative. ### Claim 15 (depends on 14) The method of claim 14 in which the material comprises at least one of an array of microscopic channels, interconnected fibers, or interconnected microspheres. ### Claim 16 (depends on 14) The method of claim 14 in which the material comprises a hydrogen-containing material. ### Claim 17 (depends on 16) The method of claim 16 in which the hydrogen-containing material comprises a polymer. ### Claim 18 (depends on 16) The method of claim 16 in which the hydrogen-containing material comprises plastic. ### Claim 19 (depends on 16) The method of claim 16 in which the hydrogen-containing material is doped with at least one of boron-10 or lithium-6. ### Claim 20 (depends on 16) The method of claim 16 in which the hydrogen-containing material defines microchannels, and a layer of neutron sensitive material is disposed on walls of the microchannels. ### Claim 21 (depends on 20) The method of claim 20 in which the neutron sensitive material comprises at least one of boron-10 or lithium-6. ### Claim 22 (depends on 14) The method of claim 14 in which the charged particles comprise electrons traveling in the bulk of the material. ### Claim 23 (depends on 14) The method of claim 14, comprising detecting an avalanche of secondary electrons traveling in a channel in the material, wherein detecting the signal at the second electrode comprises detecting the signal at the second electrode after detecting the avalanche of secondary electrons. ### Claim 24 (depends on 14) The method of claim 14 in which generating a detection signal comprises generating a detection signal indicating that a neutron has been detected when the signal at the second electrode also has an amplitude above a predetermined threshold. ### Claim 25 A method for detecting a neutron, the method comprising: providing a microchannel plate having an input electrode and an output electrode, the input electrode being connected to a first voltage, the output electrode being connected to a second voltage that is more positive than the first voltage to provide a high voltage direct current field between the input and output electrodes to accelerate electrons in channels of the microchannel plate; measuring a signal on the output electrode; and generating a signal indicating detection of a neutron when, for a first period of time, the signal at the output electrode is negative. ### Claim 26 (depends on 25) The method of claim 25 in which generating a signal indicating detection of a neutron comprises generating a signal indicating detection of a neutron when the signal at the output electrode is positive for a second period of time prior to the first period of time. ### Claim 27 A neutron detector comprising: a microchannel plate having an input electrode, an output electrode, and a glass plate comprising microscopic channels, the input electrode to be connected to a first voltage, the output electrode to be connected to a second voltage different from the first voltage to provide a high voltage direct current field between the input and output electrodes to accelerate electrons in channels of the microchannel plate; and a data processor to determine whether a neutron has been detected based on a polarity of a signal on the output electrode. ### Claim 28 (depends on 27) The neutron detector of claim 27 in which the data processor is configured to determine that a neutron has been detected when the polarity of a second signal measured at the output electrode is opposite to that of a first signal measured at the input electrode for a period of time. ### Claim 29 (depends on 28) The neutron detector of claim 28 in which the data processor is configured to determine that a neutron has been detected when the amplitude of the second signal is also above a predetermined threshold. ### Claim 30 (depends on 27) The neutron detector of claim 27 in which the data processor is configured to determine that a neutron has been detected when the polarity of first and second signals are the same for a first period of time and opposite for a second period of time, in which the first signal is measured at the input electrode and the second signal is measured at the output electrode. ### Claim 31 (depends on 27) The neutron detector of claim 27 in which the data processor is configured to detect an avalanche of secondary electrons reaching an anode associated with the microchannel plate, and determine that a neutron has been detected when, for a period of time after the avalanche of secondary electrons have been detected, the polarity of a second signal measured at the output electrode is opposite to that of a first signal measured at the input electrode. ### Claim 32 (depends on 27) The neutron detector of claim 27 in which the data processor is configured to integrate a first signal measured at the input electrode over a period of time to generate a first integral, integrate a second signal measured at the output electrode over the period of time to generate a second integral, compare the first and second integrals, and determine that a neutron has been detected based on a comparison of the first and second integrals. ### Claim 33 (depends on 32) The neutron detector of claim 32 in which the data processor is configured to determine that a neutron has been detected when the first integral and the second integral have different polarities. ### Claim 34 (depends on 27) The neutron detector of claim 27 in which the microchannel plate comprises an anode connected to a third voltage that is more positive than the second voltage, the second voltage being more positive than the first voltage, and the data processor is configured to determine that a neutron has been detected when, during a period of time, first and second signals have different polarities, and the second signal and a third signal have the same polarity, in which the first signal is measured at the input electrode, the second signal is measured at the output electrode, and the third signal is measured at the anode. ### Claim 35 (depends on 27) The neutron detector of claim 27 in which the data processor is configured to determine that a neutron has been detected when a first signal remains positive relative to a baseline value for a period of time, and a second signal is positive relative to the baseline value for a first sub-period within the period of time and is negative relative to the baseline value for a second sub-period within the period of time, in which the first signal is measured at the input electrode and the second signal is measured at the output electrode. ### Claim 36 (depends on 27) The neutron detector of claim 27, comprising a first high pass filter coupled to the input electrode, a first amplifier to amplify a first signal measured at the input electrode, a second high pass filter coupled to the output electrode, and a second amplifier to amplify a second signal measured at the output electrode. ### Claim 37 A method for detecting a neutron, the method comprising: providing a first voltage to an input electrode of a microchannel plate; providing a second voltage to an output electrode of the microchannel plate, the second voltage being more positive than the first voltage; measuring a signal on the output electrode; and providing a third voltage to an anode associated with the microchannel plate, the third voltage being more positive than the second voltage, and measuring a signal at the anode, wherein detecting a neutron comprises detecting a neutron when, during a period of time, the signal at the output electrode has a polarity that is the same as the signal at the anode. ### Claim 38 (depends on 37) The method of claim 37 in which detecting a neutron comprises determining that a neutron has been detected when the signal at the output electrode is negative for a period of time. ### Claim 39 (depends on 37) The method of claim 37 in which detecting a neutron comprises determining that a neutron has been detected when the signal at the output electrode is positive for a first period of time and negative for a second period of time. ### Claim 40 (depends on 37) The method of claim 37, comprising detecting an avalanche of secondary electrons reaching an anode of the microchannel plate, wherein detecting a neutron comprises determining that a neutron has been detected when, for a period of time after the avalanche of secondary electrons have been detected, the signal at the output electrode becomes negative. ### Claim 41 (depends on 37) The method of claim 37, comprising integrating the signal at the output electrode over a period of time to generate an integral, wherein detecting a neutron comprises detecting a neutron when the integral has a negative value. ### Claim 42 (depends on 37) The method of claim 37 in which the microchannel plate has a structure between the input and output electrodes, the structure comprising a hydrogen-containing material. ### Claim 43 A method comprising: providing a first electrode, a second electrode, and a material disposed between the first and second electrodes, the material comprising a first component that is sensitive to neutrons and a second component that is sensitive to gamma rays; providing a first voltage to the first electrode; providing a second voltage to the second electrode, the second voltage being more positive than the first voltage; discriminating between a neutron and a gamma ray by using a signal on the second electrode, the signal being influenced by moving charged particles generated as a result of an interaction between an incident particle or radiation and the material disposed between the first and second electrodes; generating a detection signal indicating that a neutron has been detected when the signal on the second electrode is negative; and detecting an avalanche of secondary electrons traveling in a channel in the material, wherein detecting the signal at the second electrode comprises detecting the signal at the second electrode after detecting the avalanche of secondary electrons. ### Claim 44 (depends on 43) The method of claim 43 in which the material comprises at least one of an array of microscopic channels, interconnected fibers, or interconnected microspheres. ### Claim 45 (depends on 43) The method of claim 43 in which the material comprises a hydrogen-containing material. ### Claim 46 A method for detecting a neutron, the method comprising: providing a microchannel plate having an input electrode and an output electrode, the input electrode being connected to a first voltage, the output electrode being connected to a second voltage that is more positive than the first voltage; and generating a signal indicating detection of a neutron when a signal at the output electrode is negative for a first period of time, and the signal at the output electrode is positive for a second period of time prior to the first period of time. ### Claim 47 (depends on 46) The method of claim 46 in which the microchannel plate has a structure between the input and output electrodes, the structure comprising a hydrogen-containing material. ### Claim 48 A neutron detector comprising: a microchannel plate having an input electrode, an output electrode, and a glass plate comprising microscopic channels, the input electrode to be connected to a first voltage, the output electrode to be connected to a second voltage different from the first voltage; and a data processor to determine whether a neutron has been detected based on a polarity of a signal on the output electrode, wherein the data processor is configured to determine that a neutron has been detected when the polarity of first and second signals are the same for a first period of time and opposite for a second period of time, in which the first signal is measured at the input electrode and the second signal is measured at the output electrode. ### Claim 49 (depends on 48) The neutron detector of claim 48 in which the data processor is configured to determine that a neutron has been detected when the polarity of a second signal measured at the output electrode is opposite to that of a first signal measured at the input electrode for a period of time. ### Claim 50 (depends on 49) The neutron detector of claim 49 in which the data processor is configured to determine that a neutron has been detected when the amplitude of the second signal is also above a predetermined threshold. ### Claim 51 (depends on 48) The neutron detector of claim 48 in which the data processor is configured to detect an avalanche of secondary electrons reaching an anode associated with the microchannel plate, and determine that a neutron has been detected when, for a period of time after the avalanche of secondary electrons have been detected, the polarity of a second signal measured at the output electrode is opposite to that of a first signal measured at the input electrode. ### Claim 52 (depends on 48) The neutron detector of claim 48 in which the data processor is configured to integrate a first signal measured at the input electrode over a period of time to generate a first integral, integrate a second signal measured at the output electrode over the period of time to generate a second integral, compare the first and second integrals, and determine that a neutron has been detected based on a comparison of the first and second integrals. ### Claim 53 (depends on 52) The neutron detector of claim 52 in which the data processor is configured to determine that a neutron has been detected when the first integral and the second integral have different polarities. ### Claim 54 (depends on 48) The neutron detector of claim 48, comprising a first high pass filter coupled to the input electrode, a first amplifier to amplify a first signal measured at the input electrode, a second high pass filter coupled to the output electrode, and a second amplifier to amplify a second signal measured at the output electrode. ### Claim 55 A neutron detector comprising: a microchannel plate having an input electrode, an output electrode, and a glass plate comprising microscopic channels, the input electrode to be connected to a first voltage, the output electrode to be connected to a second voltage different from the first voltage; and a data processor to determine whether a neutron has been detected based on a polarity of a signal on the output electrode, wherein the microchannel plate comprises an anode connected to a third voltage that is more positive than the second voltage, the second voltage being more positive than the first voltage, and the data processor is configured to determine that a neutron has been detected when, during a period of time, first and second signals have different polarities, and the second signal and a third signal have the same polarity, in which the first signal is measured at the input electrode, the second signal is measured at the output electrode, and the third signal is measured at the anode. ### Claim 56 A neutron detector comprising: a microchannel plate having an input electrode, an output electrode, and a glass plate comprising microscopic channels, the input electrode to be connected to a first voltage, the output electrode to be connected to a second voltage different from the first voltage; and a data processor to determine whether a neutron has been detected based on a polarity of a signal on the output electrode, wherein the data processor is configured to determine that a neutron has been detected when a first signal remains positive relative to a baseline value for a period of time, and a second signal is positive relative to the baseline value for a first sub-period within the period of time and is negative relative to the baseline value for a second sub-period within the period of time, in which the first signal is measured at the input electrode and the second signal is measured at the output electrode.