Digirad Corporation

Sabia Inc.

Gamma-metrics

Other

Clinton LaMar Lingren

James Francis Miller

Stanley J Friesenhahn

Boris Apotovsky

Jack F Butler

F Patrick Doty

Frank L Augustine

William L Ashburn

Stephen James Foster

Richard Louis Conwell

Thomas L Atwell

David B Cook

Abhinandan Sheshadri

Thomas Charles Dannemiller

Nichelle Diane Worthington

Bradley Allen Moyer

Bo Pi

Raymond J Proctor

Ashot Oganesyan

Ernesto A Corte

F Patrick Dory

Methods and systems are provided to improve PGNAA substance analyzers. In one aspect, an analyzer includes: a source of neutrons; an opening to receive a substance; a gamma ray detector; and computational device(s) configured to receive spectral data of detected gamma rays, perform a regression algorithm on the spectral data using spectral responses for known atomic elements to determine coefficients of spectrum, sum effective weight values (corresponding to the coefficients of spectrum) together to form a total effective weight value for the substance being analyzed, divide effective weight values by the total effective weight value for the substance to generate effective weight-percent values corresponding to two or more respective ones of the atomic elements detected in the spectral data, and generate final weight-percent values based on a correlation of previous effective weight-percent values obtained for known samples with elemental or molecular weight-percent values obtained for the known samples.

Weight-percent analysis for prompt gamma neutron activation substance analyzers

Methods and systems are provided to improve prompt gamma neutron activation substance analyzers. In one aspect, a detector unit for prompt gamma neutron activation analysis includes: a scintillator configured to fluoresce when impacted by gamma rays generated by absorption of neutrons by a substance to be analyzed; a photosensor configured to receive fluorescence from the scintillator; electronics coupled with the photosensor, the electronics configured to receive and process analog signals from the photosensor and output digital detection signals for the substance; and a housing containing the scintillator, the photosensor, and the electronics; wherein the housing includes interfaces configured to receive cables capable of providing power, temperature control, and digital communication signals.

Prompt gamma neutron activation substance analyzers

Methods and systems are provided to improve prompt gamma neutron activation substance analyzers. In one aspect, a substance analyzer unit includes: a source of neutrons; an opening arranged with respect to the source of neutrons to receive a substance; and a detector housing having (i) a detector configured and arranged to receive gamma rays generated by absorption of neutrons by the substance, and (ii) electronics coupled with the detector within the detector housing, wherein the electronics are configured to receive and process analog signals from the detector and output digital detection signals.

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.

Method and apparatus for analysis of elements in bulk substance

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. The fall-through circuit searches for the next detection element and associated channel having a valid event. The signal processor performs diagnostics, gain normalization, and response efficiency normalization functions. The data acquisition system controls the acquisition and processing of data received from the conditioning and processing channels, produces image data based upon the data in a format that is compatible with existing imaging cameras, and transmits the data to the image processing computer. The image processing computer formulates images based upon the processed signals and displays the formulated images on a display device.

Semiconductor gamma-ray camera and medical imaging system

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. A fourth electrode can be added to separate the charge-shielding and field shaping functions of the control electrode. More electrodes can be added to further enhance both functions. The invention can be used in several cross-strip detector configurations, in a side-entry radiation detector, and with liquid/gas ionization detectors.

Semiconductor radiation detector with enhanced charge collection

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. The fall-through circuit searches for the next detection element and associated channel having a valid event. The signal processor performs diagnostics, gain normalization, and response efficiency normalization functions. The data acquisition system controls the acquisition and processing of data received from the conditioning and processing channels, produces image data based upon the data in a format that is compatible with existing imaging cameras, and transmits the data to the image processing computer. The image processing computer formulates images based upon the processed signals and displays the formulated images on a display device.

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.

Semiconductor gamma- ray camera and medical imaging system

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. High-voltage decoupling circuitry can be eliminated by maintaining the coplanar signal strips at substantially the same voltage.

Radiation detector with shielding electrode

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. A high-voltage decoupling circuit is implemented on the signal collecting side with high-voltage capacitors arranged in a cord-wood configuration to allow for all-side buttability. A thin circuit layer is formed on a lateral side of the semiconductor to transfer the signals from the radiation side to the signal collecting side. A shield electrode may also be formed on the signal collecting side and be capacitively coupled to the semiconductor to reduce the effect on the anodes of charge trapping in the semiconductor.

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San Diego, CA, United States of America

Clinton LaMar Lingren