Abstract: A substance analyzer utilizing Prompt Gamma Neutron Activation Analysis for identifying characteristics of a substance and method of manufacturing the same are disclosed. The analyzer is small enough to be portable and to allow its use in many applications where current analyzers cannot be utilized. The analyzer uses a neutron radiation source and a gamma-ray detector to activate the sample material and detect the prompt gamma rays emitted by the sample material. A novel housing for such an analyzer and method for making the housing are also described. Novel methods of operating such an analyzer including via a communications network are also disclosed. Also disclosed are data analysis methods that improve the accuracy and sensitivity of the results of such material analysis.

Abstract: A substance analyzer utilizing Prompt Gamma Neutron Activation Analysis for identifying characteristics of a substance and method of manufacturing the same are disclosed. The analyzer is small enough to be portable and to allow its use in many applications where current analyzers cannot be utilized. The analyzer uses a neutron radiation source and a gamma-ray detector to activate the sample material and detect the prompt gamma rays emitted by the sample material. A novel housing for such an analyzer and method for making the housing are also described. Novel methods of operating such an analyzer including via a communications network are also disclosed. Also disclosed are data analysis methods that improve the accuracy and sensitivity of the results of such material analysis.

Abstract: A substance analyzer utilizing Prompt Gamma Neutron Activation Analysis for identifying characteristics of a substance and method of manufacturing the same are disclosed. The analyzer is small enough to be portable and to allow its use in many applications where current analyzers cannot be utilized. The analyzer uses a neutron radiation source and a gamma-ray detector to activate the sample material and detect the prompt gamma rays emitted by the sample material. A novel housing for such an analyzer and method for making the housing are also described. Novel methods of operating such an analyzer including via a communications network are also disclosed. Also disclosed are data analysis methods that improve the accuracy and sensitivity of the results of such material analysis.

Abstract: A high-energy photon imaging system including an imaging head, a signal processor, a data acquisition system and an image processing computer. The imaging head includes a detector comprising a plurality of closely-packed detection modules. Each detection module comprises a plurality of detection elements mounted to a circuit carrier. The detection elements produce electrical pulses having amplitudes indicative of the magnitude of radiation absorbed by the detection elements. The circuit carrier includes channels for conditioning and processing the signals generated by corresponding detection elements and for preparing the processed signals for further processing by a signal processor. Each conditioning and processing channel stores the amplitudes of the detection element electrical pulses exceeding a predetermined threshold. The detection modules employ a fall-through circuit which automatically finds only those detection elements that have a stored pulse amplitude exceeding the threshold.

Abstract: A high-energy photon imaging system including an imaging head, a signal processor, a data acquisition system and an image processing computer. The imaging head includes a detector comprising a plurality of closely-packed detection modules. Each detection module comprises a plurality of detection elements mounted to a circuit carrier. The detection elements produce electrical pulses having amplitudes indicative of the magnitude of radiation absorbed by the detection elements. The circuit carrier includes channels for conditioning and processing the signals generated by corresponding detection elements and for preparing the processed signals for further processing by a signal processor. Each conditioning and processing channel stores the amplitudes of the detection element electrical pulses exceeding a predetermined threshold. The detection modules employ a fall-through circuit which automatically finds only those detection elements that have a stored pulse amplitude exceeding the threshold.

Abstract: A radiation detector for detecting ionizing radiation. The detector includes a semiconductor having at least two sides. A bias electrode is formed on one side of the semiconductor. A signal electrode is formed on a side of the semiconductor and is used to detect the energy level of the ionizing radiation. A third electrode (the control electrode) is also formed on the semiconductor. The control electrode shares charges induced by the ionizing radiation with the signal electrode, shielding the signal electrode until the charge clouds are close to the signal electrode. The control electrode also alters the electric field within the semiconductor, such that the field guides the charge clouds toward the signal electrode when the clouds closely approach the signal electrode. As a result, signal loss due to trapped charge carriers (i.e., electrons or holes) is minimized, and low-energy tailing is virtually eliminated.

Abstract: A radiation detector for detecting ionizing radiation. The detector includes a semiconductor having at least two sides. A bias electrode is formed on one side of the semiconductor. A signal electrode is formed on a side of the semiconductor and is used to detect the energy level of the ionizing radiation. A third electrode (the control electrode) is also formed on the semiconductor. The control electrode shares charges induced by the ionizing radiation with the signal electrode, shielding the signal electrode until the charge clouds are close to the signal electrode. The control electrode also alters the electric field within the semiconductor, such that the field guides the charge clouds toward the signal electrode when the clouds closely approach the signal electrode. As a result, signal loss due to trapped charge carriers (i.e., electrons or holes) is minimized, and low-energy tailing is virtually eliminated.

Abstract: A high-energy photon imaging system including an imaging head, a signal processor, a data acquisition system and an image processing computer. The imaging head includes a detector comprising a plurality of closely-packed detection modules. Each detection module comprises a plurality of detection elements mounted to a circuit carrier. The detection elements produce electrical pulses having amplitudes indicative of the magnitude of radiation absorbed by the detection elements. The circuit carrier includes channels for conditioning and processing the signals generated by corresponding detection elements and for preparing the processed signals for further processing by a signal processor. Each conditioning and processing channel stores the amplitudes of the detection element electrical pulses exceeding a predetermined threshold. The detection modules employ a fall-through circuit which automatically finds only those detection elements that have a stored pulse amplitude exceeding the threshold.

Abstract: A high-energy photon imaging system including an imaging head, a signal processor, a data acquisition system and an image processing computer. The imaging head includes a detector including a plurality of closely-packed detection modules. Each detection module includes a plurality of detection elements mounted to a circuit carrier. The detection elements produce electrical pulses having amplitudes indicative of the magnitude of radiation absorbed by the detection elements. The circuit carrier includes channels for conditioning and processing the signals generated by corresponding detection elements and for preparing the processed signals for further processing by a signal processor. Each conditioning and processing channel stores the amplitudes of the detection element electrical pulses exceeding a predetermined threshold. The detection modules employ a fall-through circuit which automatically finds only those detection elements that have a stored pulse amplitude exceeding the threshold.

Abstract: A high-energy photon imaging system including an imaging head, a signal processor, a data acquisition system and an image processing computer. The imaging head includes a detector including a plurality of closely-packed detection modules. Each detection module includes a plurality of detection elements mounted to a circuit carrier. The detection elements produce electrical pulses having amplitudes indicative of the magnitude of radiation absorbed by the detection elements.

Abstract: A high-energy photon imaging system including an imaging head, a signal processor, a data acquisition system and an image processing computer. The imaging head includes a detector comprising a plurality of closely-packed detection modules. Each detection module comprises a plurality of detection elements mounted to a circuit carrier. The detection elements produce electrical pulses having amplitudes indicative of the magnitude of radiation absorbed by the detection elements. The circuit carrier includes channels for conditioning and processing the signals generated by corresponding detection elements and for preparing the processed signals for further processing by a signal processor. Each conditioning and processing channel stores the amplitudes of the detection element electrical pulses exceeding a predetermined threshold. The detection modules employ a fall-through circuit which automatically finds only those detection elements that have a stored pulse amplitude exceeding the threshold.

Abstract: A radiation detector for detecting ionizing radiation. The detector includes a semiconductor having at least two sides. A bias electrode is formed on one side of the semiconductor. A signal electrode is formed on a side of the semiconductor and is used to detect the energy level of the ionizing radiation. A third electrode (the control electrode) is also formed on the semiconductor. The control electrode shares charges induced by the ionizing radiation with the signal electrode, shielding the signal electrode until the charge clouds are close to the signal electrode. The control electrode also alters the electric field within the semiconductor, such that the field guides the charge clouds toward the signal electrode when the clouds closely approach the signal electrode. As a result, signal loss due to trapped charge carriers (i.e., electrons or holes) is minimized, and low-energy tailing is virtually eliminated.

Abstract: A cross-strip radiation detector for detecting ionizing radiation with two non-parallel sets of signal strips formed on the same side of the detector. The detector includes a semiconductor having at least two sides. A bias electrode is formed on one side of the semiconductor. A signal electrode is formed on a side of the semiconductor and is used to detect the energy level of the ionizing radiation. A third electrode (the control electrode) is also formed on the semiconductor. The control electrode shares charges induced by the ionizing radiation with the signal electrode, shielding the signal electrode until the charge clouds are close to the signal electrode. The control electrode also alters the electric field within the semiconductor, such that the field guides the charge clouds toward the signal electrode when the clouds closely approach the signal electrode. Large detector arrays can be formed by butting such coplanar cross-strip detectors side-by-side without little dead area.

Abstract: A cross-strip radiation detector for detecting ionizing radiation. The detector includes a semiconductor having at least two sides, a radiation side and an opposing signal collecting side. A plurality of parallel radiation-side electrode strips are formed on the radiation side of the semiconductor. Multiple of signal-collecting-side electrodes are formed on a signal collecting side of the semiconductor and are connected to form a plurality of parallel signal strips that are not parallel to the radiation-side electrode strips. For common semiconductors, anodes are used to detect the energy level of the ionizing radiation. The signals from the cathode strips are used in conjunction with the signals from the anodes to determine the location of an ionizing event. At least one additional electrode, a control electrode, may also be formed on the semiconductor to alter the electric field within the semiconductor to improve the collection efficiency of the signal electrode.

Abstract: A high-energy photon imaging system including an imaging head, a signal processor, a data acquisition system and an image processing computer. The imaging head includes a detector comprising a plurality of closely-packed detection modules. Each detection module comprises a plurality of detection elements mounted to a circuit carrier. The detection elements produce electrical pulses having amplitudes indicative of the magnitude of radiation absorbed by the detection elements. The circuit carrier includes channels for conditioning and processing the signals generated by corresponding detection elements and for preparing the processed signals for further processing by a signal processor. Each conditioning and processing channel stores the amplitudes of the detection element electrical pulses exceeding a predetermined threshold. The detection modules employ a fall-through circuit which automatically finds only those detection elements that have a stored pulse amplitude exceeding the threshold.

Abstract: A high-energy photon imaging system including an imaging head, a signal processor, a data acquisition system and an image processing computer. The imaging head includes a detector comprising a plurality of closely-packed detection modules. Each detection module comprises a plurality of detection elements mounted to a circuit carrier. The detection elements produce electrical pulses having amplitudes indicative of the magnitude of radiation absorbed by the detection elements. The circuit carrier includes channels for conditioning and processing the signals generated by corresponding detection elements and for preparing the processed signals for further processing by a signal processor. Each conditioning and processing channel stores the amplitudes of the detection element electrical pulses exceeding a predetermined threshold. The detection modules employ a fall-through circuit which automatically finds only those detection elements that have a stored pulse amplitude exceeding the threshold.

Abstract: A radiation detector for detecting ionizing radiation. The detector includes a semiconductor having at least two sides. A bias electrode is formed on one side of the semiconductor. A signal electrode is formed on a side of the semiconductor and is used to detect the energy level of the ionizing radiation. A third electrode (the control electrode) is also formed on the semiconductor. The control electrode shares charges induced by the ionizing radiation with the signal electrode, until the charge clouds are close to the signal electrode. The control electrode also alters the electric field within the semiconductor, such that the field guides the charge clouds toward the signal electrode when the clouds closely approach the signal electrode. As a result, trapping of charge carrying radiation (i.e., electrons or holes) is minimized, and low-energy tailing is virtually eliminated.

Abstract: A calibration block is used for calibrating a bulk material analyzer that has an activation region in which bulk material is received for analysis and a chute for passing the bulk material through the activation region. The block is dimensioned to be of almost the same cross-sectional size as the interior of the chute and extends both above and below the activation region when inserted in the chute. The calibration block is manufactured by (a) providing a mixture of known materials of known proportions that do not chemically react with each other, including a bonding agent; (b) homogenizing the mixture to make a thick paste in which the known materials are bound without segregation of known materials that have different densities; (c) molding the homogeneous mixture into the shape of a block having predetermined dimensions; and (d) solidifying the molded mixture to provide the calibration block.

Abstract: A complete PGNAA bulk material analyzer is self contained in a sealed and air conditioned housing. Bulk material is channeled by an open-ended vertical chute having a one-foot-by-three-foot cross-sectional dimension through an activation region between three neutron sources and two gamma ray detectors. The sources are symmetrically disposed on one of the three-foot long sides of the chute from one end of such side to the other. The detectors are symmetrically disposed on the opposite side of the chute between positions opposing the positions of the sources on the one side of the chute. The chute is dimensioned to enable free flow of various bulk materials. It handles coal of up to a top size of four inches and with typical surface moisture contents and agglomeration characteristics. The relative disposition of the sources and detectors results in the measurements being independent of the lateral distribution of the bulk material within the chute.

Abstract: A fission chamber detector system for monitoring neutron flux density in a nuclear reactor includes a preamplifier and signal conditioning unit for amplifying and conditioning neutron signal pulses produced by fission chamber detectors located adjacent the reactor core. The preamplifier and signal conditioning unit are located outside of the containment vessel for the reactor. The amplifier and signal conditioning unit amplify and condition the neutron signal pulses to provide signals that can be transmitted by twisted shielded pairs to a remotely located signal processing unit. The preamplifiers include an input stage that enables the preamplifiers to be controlled remotely to either pass or inhibit neutron signal pulses to an amplifier stage from the fission chambers, and to pass test signals to the amplifier stage.