Abstract: An apparatus for cosmogenic neutron sensing to detect moisture includes a thermal neutron proportional counter. A housing is formed at least partially from a moderating material, which is positioned around the thermal neutron proportional counter. A proportional counter electronics unit is within the housing and has a preamplifier and a shaping amplifier. The preamplifier and shaping amplifier are directly connected to the thermal neutron proportional counter. At least one photovoltaic panel provides electrical power to the thermal neutron proportional counter. A data logger is positioned vertically above the thermal neutron proportional counter and proportional counter electronics unit. A signal from the thermal neutron proportional counter is transmitted through the proportional counter electronics unit and is received by the data logger. The signal indicates a moisture content within a measurement surface of the thermal neutron proportional counter.

Abstract: A wide area cosmogenic neutron sensor is used for detecting moisture within a measurement surface. A neutron detector is positioned on a stand structure holding the detector above a measurement surface. A moderator material and neutron shield are positioned around at least a portion of the neutron detector. The neutron shield substantially covers an entirety of a bottom of the neutron detector and is not positioned on a top side of the neutron detector. Wide area cosmogenic neutrons propagating from the measurement surface travel through an air space before arriving at the moderated neutron detector.

Abstract: A local area, thermal cosmogenic neutron sensor is used for detecting moisture within a measurement surface. A neutron detector is positioned on a stand structure holding the detector above a measurement surface. A neutron shield is positioned around at least a portion of the neutron detector. The neutron shield substantially covers lateral sides of the neutron detector and substantially an entirety of a top of the neutron detector and is not positioned on a bottom side of the neutron detector. Local area, thermal cosmogenic neutrons propagating from the measurement surface travel through an air space before arriving at the neutron detector.

Abstract: An apparatus for cosmogenic neutron sensing to detect moisture includes a thermal neutron proportional counter. A housing is formed at least partially from a moderating material, which is positioned around the thermal neutron proportional counter. A proportional counter electronics unit is within the housing and has a preamplifier and a shaping amplifier. The preamplifier and shaping amplifier are directly connected to the thermal neutron proportional counter. At least one photovoltaic panel provides electrical power to the thermal neutron proportional counter. A data logger is positioned vertically above the thermal neutron proportional counter and proportional counter electronics unit. A signal from the thermal neutron proportional counter is transmitted through the proportional counter electronics unit and is received by the data logger. The signal indicates a moisture content within a measurement surface of the thermal neutron proportional counter.

Abstract: A local area cosmogenic neutron sensor is used for detecting moisture within a measurement surface. A neutron detector is positioned on a stand structure holding the detector above a measurement surface. A moderator material and neutron shield are positioned around at least a portion of the neutron detector. The neutron shield substantially covers lateral sides and an entirety of a top of the neutron detector and is not positioned on a bottom side of the neutron detector. A thermal neutron shield is positioned below the neutron detector and in a path of neutron travel between the measurement surface and the neutron detector to substantially block environmental thermal neutrons from reaching the neutron detector, which improves the signal-to-noise ratio and signal contrast of the local area cosmogenic neutron sensor.

Abstract: A wide area cosmogenic neutron sensor is used for detecting moisture within a measurement surface. A neutron detector is positioned on a stand structure holding the detector above a measurement surface. A moderator material and neutron shield are positioned around at least a portion of the neutron detector. The neutron shield substantially covers an entirety of a bottom of the neutron detector and is not positioned on a top side of the neutron detector. Wide area cosmogenic neutrons propagating from the measurement surface travel through an air space before arriving at the moderated neutron detector.

Abstract: A local area cosmogenic neutron sensor is used for detecting moisture within a measurement surface. A neutron detector is positioned on a stand structure holding the detector above a measurement surface. A moderator material and neutron shield are positioned around at least a portion of the neutron detector. The neutron shield substantially covers lateral sides and an entirety of a top of the neutron detector and is not positioned on a bottom side of the neutron detector. A thermal neutron shield is positioned below the neutron detector and in a path of neutron travel between the measurement surface and the neutron detector to substantially block environmental thermal neutrons from reaching the neutron detector, which improves the signal-to-noise ratio and signal contrast of the local area cosmogenic neutron sensor.

Abstract: A cosmogenic neutron sensor includes a hydrogen-sensitive neutron detector orientable above a measurement surface. A neutron shield is positionable on the hydrogen-sensitive neutron detector. The neutron shield is positioned to interact with at least a portion of cosmogenic neutrons propagating in a direction of the hydrogen-sensitive neutron detector.

Abstract: A moderated neutron detector includes a neutron detector having a first volume. A moderating enclosure is positioned around the neutron detector and encloses a second volume. The second volume is between 2 and 80 times larger than the first volume. A method for increased neutron detection includes the following steps: positioning a neutron detector within a moderating enclosure, wherein the neutron detector has a first volume, wherein the moderating enclosure encloses a second volume, and wherein the second volume is between 2 and 80 times larger than the first volume; increasing a quantity of neutrons impingent upon the neutron detector; and measuring the quantity of neutrons impinging upon the neutron detector.

Abstract: A moderated neutron detector includes a neutron detector having a first volume. A moderating enclosure is positioned around the neutron detector and encloses a second volume. The second volume is between 2 and 80 times larger than the first volume. A method for increased neutron detection includes the following steps: positioning a neutron detector within a moderating enclosure, wherein the neutron detector has a first volume, wherein the moderating enclosure encloses a second volume, and wherein the second volume is between 2 and 80 times larger than the first volume; increasing a quantity of neutrons impingent upon the neutron detector; and measuring the quantity of neutrons impinging upon the neutron detector.

Abstract: A cosmogenic neutron sensor includes a hydrogen-sensitive neutron detector orientable above a measurement surface. A neutron shield is positionable on the hydrogen-sensitive neutron detector. The neutron shield is positioned to interact with at least a portion of cosmogenic neutrons propagating in a direction of the hydrogen-sensitive neutron detector.

Abstract: An external cavity structure including: a light source for generating a light beam; a dispersive system which in combination with the light source defines a cavity, the dispersive system for directing a selected wavelength of the light beam back into the light source, the dispersive system including a grating for selecting said wavelength of the light beam; and a beam-conditioner positioned within the cavity along a light path between the light source and the dispersive system, the beam conditioner including a beam deflecting element for changing the direction of propagation of the light beam as that light beam that travels between the light source and the dispersive system.

Abstract: An interferometric system including: an interferometer that directs a measurement beam at an object point to produce a return measurement beam, focuses the return measurement beam to an image point in an image plane, and mixes the return measurement beam with a reference beam at the image point to form a mixed beam; a beam combining layer located at the image plane which is responsive to the mixed beam and produces an optical beam therefrom, wherein the layer comprises a thin film with an array of transmissive openings formed therein and further comprises a fluorescent material associated with each of the openings of the array of openings; a detector that is responsive to the optical beam from the beam combining layer; and an imaging system that directs the optical beam from the beam combining layer onto the detector.