# US 9,651,688 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 9,651,688 B2 - Document ID: US9651688B2 - Status: Granted - Kind: B2 - Application number: 15/082,226 - Filed: 2016-03-28 - Published: 2016-11-03 - Granted: 2017-05-16 - 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/US9651688B2 ## 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 first signal on the input electrode; measuring a second signal on the output electrode; and detecting a neutron based on a comparison of the first and second signals. ### 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 polarity of the second signal is opposite to that of the first signal 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 second signal 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 polarity of the first and second signals are the same for a first period of time and opposite for a second period of time. ### Claim 5 (depends on 4) The method of claim 4 in which 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 polarity of the second signal is opposite to that of the first signal. ### Claim 6 (depends on 1) The method of claim 1, comprising detecting an avalanche of secondary electrons reaching an anode of the microchannel plate. ### Claim 7 (depends on 1) The method of claim 1, comprising integrating the first signal over a period of time to generate a first integral, integrating the second signal over the period of time to generate a second integral, wherein detecting a neutron comprises detecting a neutron based on a comparison of the first and second integrals. ### Claim 8 (depends on 7) The method of claim 7 in which detecting a neutron comprises detecting a neutron when the first integral and the second integral have different polarities. ### Claim 9 (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. ### Claim 10 (depends on 9) The method of claim 9, comprising measuring a third signal at the anode, wherein detecting a neutron comprises detecting a neutron when, during a period of time, the first and second signals have different polarities, and the second and third signals have the same polarity. ### Claim 11 (depends on 1) The method of claim 1 in which detecting a neutron comprises detecting a neutron when the first signal remains positive relative to a baseline value for a period of time, and the 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. ### Claim 12 (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 13 (depends on 12) The method of claim 12 in which the hydrogen-containing material comprises a polymer. ### Claim 14 (depends on 12) The method of claim 12 in which the hydrogen-containing material comprises plastic. ### Claim 15 (depends on 12) The method of claim 12 in which the hydrogen-containing material is doped with at least one of boron-10 or lithium-6. ### Claim 16 (depends on 12) The method of claim 12 in which the hydrogen-containing material defines microchannels, and a layer of neutron sensitive material is disposed on walls of the microchannels. ### Claim 17 (depends on 16) The method of claim 16 in which the neutron sensitive material comprises at least one of boron-10 or lithium-6. ### Claim 18 A method comprising: discriminating between a neutron and a gamma ray by using a first signal on a first electrode and a second signal on a second electrode, the first and second signals being influenced by moving charged particles generated as a result of an interaction between an incident particle or radiation 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, in which a first voltage is provided to the first electrode, a second voltage is provided 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; and generating a detection signal indicating that a neutron has been detected when the first signal and the second signal have different polarities. ### Claim 19 (depends on 18) The method of claim 18 in which the material comprises at least one of an array of microscopic channels, interconnected fibers, or interconnected microspheres. ### Claim 20 (depends on 18) The method of claim 18 in which the material comprises a hydrogen-containing material. ### Claim 21 (depends on 20) The method of claim 20 in which the hydrogen-containing material comprises a polymer. ### Claim 22 (depends on 20) The method of claim 20 in which the hydrogen-containing material comprises plastic. ### Claim 23 (depends on 18) The method of claim 18 in which the charged particles comprise electrons traveling in the bulk of the material. ### Claim 24 (depends on 18) The method of claim 18, comprising detecting an avalanche of secondary electrons traveling in a channel in the material, wherein detecting the first and second signals comprises detecting the first and second signals after detecting the avalanche of secondary electrons. ### Claim 25 (depends on 18) The method of claim 18 in which generating a detection signal comprises generating a detection signal indicating that a neutron has been detected when the second signal also has an amplitude above a predetermined threshold. ### Claim 26 A method for detecting a neutron, the method comprising: providing a microchannel plate having an input electrode and an output electrode, the input and output electrodes being connected to different voltages to provide a high voltage direct current field between the input and output electrodes to accelerate electrons in channels of the microchannel plate; and generating a signal indicating detection of a neutron when, for a first period of time, a first signal at the output electrode has a polarity different from the polarity of a second signal at the input electrode. ### Claim 27 (depends on 26) The method of claim 26 in which generating a signal indicating detection of a neutron comprises generating a signal indicating detection of a neutron when the first and second signals have the same polarity for a second period of time prior to the first period of time. ### Claim 28 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 comparison of a first signal on the input electrode and a second 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, the first and second signals have different polarities, and the second and third signals have the same polarity. ### 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 polarity of the second signal is opposite to that of the first signal for a period of time. ### Claim 30 (depends on 29) The neutron detector of claim 29 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 31 (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 polarity of the first and second signals are the same for a first period of time and opposite for a second period of time. ### Claim 32 (depends on 28) The neutron detector of claim 28 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 the second signal is opposite to that of the first signal. ### Claim 33 (depends on 28) The neutron detector of claim 28 in which the data processor is configured to integrate the first signal over a period of time to generate a first integral, integrate the second signal 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 34 (depends on 33) The neutron detector of claim 33 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 35 (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 first signal remains positive relative to a baseline value for a period of time, and the 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. ### Claim 36 (depends on 28) The neutron detector of claim 28, comprising a first high pass filter coupled to the first electrode, a first amplifier to amplify the first signal, a second high pass filter coupled to the second electrode, and a second amplifier to amplify the second signal. ### Claim 37 (depends on 28) The neutron detector of claim 28 in which the microchannel plate has a structure between the input and output electrodes, the structure comprising a hydrogen-containing material. ### Claim 38 (depends on 37) The neutron detector of claim 37 in which the hydrogen-containing material comprises a polymer. ### Claim 39 (depends on 37) The neutron detector of claim 37 in which the hydrogen-containing material comprises plastic. ### Claim 40 (depends on 37) The neutron detector of claim 37 in which the hydrogen-containing material is doped with at least one of boron-10 or lithium-6. ### Claim 41 (depends on 37) The neutron detector of claim 37 in which the hydrogen-containing material defines microchannels, and a layer of neutron sensitive material is disposed on walls of the microchannels. ### Claim 42 (depends on 41) The neutron detector of claim 41 in which the neutron sensitive material comprises at least one of boron-10 or lithium-6. ### Claim 43 (depends on 28) The neutron detector of claim 28, comprising additional pairs of input and output electrodes, a portion of the glass plate being disposed between each pair of input and output electrodes, and for each additional pair of input and output electrodes, the data processor is configured to discriminate between a neutron and a gamma ray by using a third signal on the input electrode and a fourth signal on the output electrode, the third and fourth signals being influenced by moving charged particles generated as a result of an interaction between an incident particle or radiation and the portion of the glass plate disposed between the pair of input and output electrodes, the data processor configured to determine that a neutron has been detected when the third signal and the fourth signal have different polarities for a period of time. ### Claim 44 (depends on 43) The neutron detector of claim 43 in which the material disposed between the first and second electrodes comprises a hydrogen-containing material. ### Claim 45 (depends on 44) The neutron detector of claim 44 in which the hydrogen-containing material comprises a polymer. ### Claim 46 (depends on 44) The neutron detector of claim 44 in which the hydrogen-containing material comprises plastic. ### Claim 47 (depends on 44) The neutron detector of claim 44 in which the hydrogen-containing material is doped with at least one of boron-10 or lithium-6. ### Claim 48 (depends on 44) The neutron detector of claim 44 in which the hydrogen-containing material defines microchannels, and a layer of neutron sensitive material is disposed on walls of the microchannels. ### Claim 49 (depends on 48) The neutron detector of claim 48 in which the neutron sensitive material comprises at least one of boron-10 or lithium-6. ### Claim 50 (depends on 49) The neutron detector of claim 49 in which the microchannel plate has a structure between the input and output electrodes, the structure comprising a hydrogen-containing material. ### Claim 51 (depends on 50) The neutron detector of claim 50 in which the hydrogen-containing material comprises a polymer. ### Claim 52 (depends on 50) The neutron detector of claim 50 in which the hydrogen-containing material comprises plastic. ### Claim 53 (depends on 50) The neutron detector of claim 50 in which the hydrogen-containing material is doped with at least one of boron-10 or lithium-6. ### Claim 54 (depends on 50) The neutron detector of claim 50 in which the hydrogen-containing material defines microchannels, and a layer of neutron sensitive material is disposed on walls of the microchannels. ### Claim 55 (depends on 54) The neutron detector of claim 54 in which the neutron sensitive material comprises at least one of boron-10 or lithium-6. ### Claim 56 (depends on 49) The neutron detector of claim 49 in which the microchannel plate has a plurality of output electrodes, each output electrode being coupled to an electronic circuit for detecting a signal on the corresponding output electrode. ### Claim 57 (depends on 43) The neutron detector of claim 43, comprising additional pairs of electrodes, a portion of the material being disposed between each pair of electrodes, and for each pair of electrodes, the data processor is configured to discriminate between a neutron and a gamma ray by using a third signal on one of the pair of electrodes and a fourth signal on another of the pair of electrodes, the third and fourth signals being influenced by moving charged particles generated as a result of an interaction between an incident particle or radiation and the portion of material disposed between the pair of electrodes, the data processor configured to determine that a neutron has been detected when the third signal and the fourth signal have different polarities for a period of time. ### Claim 58 A neutron detector comprising: a first electrode; a second electrode; 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; and a data processor configured to discriminate between a neutron and a gamma ray by using a first signal on the first electrode and a second signal on the second electrode, the first and second signals 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, the data processor configured to determine that a neutron has been detected when the first signal and the second signal have different polarities for a period of time; wherein the data processor is configured to detect an avalanche of secondary electrons traveling in a channel in the material, and detect the first and second signals after detecting the avalanche of secondary electrons. ### Claim 59 (depends on 58) The neutron detector of claim 58 in which the material comprises at least one of an array of microscopic channels, interconnected fibers, or interconnected microspheres. ### Claim 60 (depends on 58) The neutron detector of claim 58 in which the charged particles comprise electrons traveling in the bulk of the material. ### Claim 61 (depends on 58) The neutron detector of claim 58 in which the data processor is configured to generate a detection signal indicating that a neutron has been detected when the second signal also has an amplitude above a predetermined threshold. ### Claim 62 A neutron detector comprising: a microchannel plate having an input electrode and an output electrode, the input and output electrodes being connected to different voltages 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 configured to determine that a neutron has been detected when, for a first period of time, a first signal at the output electrode has a polarity different from the polarity of a second signal at the input electrode. ### Claim 63 (depends on 62) The neutron detector of claim 62 in which the data processor is configured to generate a signal indicating detection of a neutron when the first and second signals have the same polarity for a first period of time, and have opposite polarities for a second period of time. ### Claim 64 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 comparison of a first signal on the input electrode and a second signal on the output electrode; wherein the data processor is configured to determine that a neutron has been detected when the first signal remains positive relative to a baseline value for a period of time, and the 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. ### Claim 65 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; providing a third voltage to an anode associated with the microchannel plate, the third voltage being more positive than the second voltage; measuring a first signal on the input electrode; measuring a second signal on the output electrode; and detecting a neutron based on a comparison of the first and second signals. ### Claim 66 (depends on 65) The method of claim 65, comprising measuring a third signal at the anode, wherein detecting a neutron comprises detecting a neutron when, during a period of time, the first and second signals have different polarities, and the second and third signals have the same polarity. ### Claim 67 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 first signal on the input electrode; measuring a second signal on the output electrode; and detecting a neutron based on a comparison of the first and second signals; wherein detecting a neutron comprises detecting a neutron when the first signal remains positive relative to a baseline value for a period of time, and the 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.