Abstract: A multi-radiation identification and dosimetry system and method that allows for monitoring of alpha, beta, and gamma radiation is disclosed. The system/method incorporates a segmented silicon drift detector (SSDD) that allows measurement of directly absorbed radiation in the semiconductor (betas, conversion electrons, Lx lines, and alphas) on one SSDD segment and radiation from a radiation scintillation detector (RSD) on multiple segments of the SSDD. With the anode side of the SSDD directed toward the radiation inspection surface (RIS), the SSDD+RSD stacked radiation detector collects radiation which is processed by a charge sensitive amplifier (CSA) and then processed by a time stamping differentiator (TSD). A computing control device (CCD) may be configured to collect the time stamp differentiation data from the various SSDD segments to permit the simultaneous discrimination of several types of radiation by and presentation of these radiation types and counts on a display monitor.

Abstract: A nuclide decay discriminator system and method is disclosed. The system utilizes a digital computing device (DCD) to capture radiation counts from a radiation detection device (RDD) such as a photon detector via the use of one or more integrated analog-to-digital converters (ADC). The radiation count information is then processed using a recursive procedure in the DCD that determines the desired nuclide to be evaluated and then defines the possible nuclide decay transition states. For each possible nuclide decay state, a recursive permutation of possible state transitions from this nuclide state is determined using a state permutation engine (SPE). Combinations of these state transition branches are linked to form state transition chains each having individual probabilities associated with the overall state transition chain. These state transition chain probabilities are applied to the RDD ADC data to form observed RDD radiation data radiation count probabilities and displayed in real-time.

Abstract: A nuclide decay discriminator system and method is disclosed. The system utilizes a digital computing device (DCD) to capture radiation counts from a radiation detection device (RDD) such as a photon detector via the use of one or more integrated analog-to-digital converters (ADC). The radiation count information is then processed using a recursive procedure in the DCD that determines the desired nuclide to be evaluated and then defines the possible nuclide decay transition states. For each possible nuclide decay state, a recursive permutation of possible state transitions from this nuclide state is determined using a state permutation engine (SPE). Combinations of these state transition branches are linked to form state transition chains each having individual probabilities associated with the overall state transition chain. These state transition chain probabilities are applied to the RDD ADC data to form observed RDD radiation data radiation count probabilities and displayed in real-time.

Abstract: A radiation detector system/method that simultaneously detects alpha/beta, beta/gamma, or alpha/beta/gamma radiation within an integrated detector is disclosed. The system incorporates a photomultiplier tube with radiation scintillation materials to detect alpha/beta/gamma radiation. The photomultiplier tube output is then shape amplified and fed through discriminators to detect the individual radiation types. The discriminator outputs are fed to an anti-coincidence and pulse width and timing analysis module that determines whether individual alpha/beta/gamma pulses are valid and should be counted by corresponding alpha/beta/gamma pulse radiation counters. The system may include a radiation detection method to affect alpha/beta/gamma radiation detection in a variety of contexts. The system/method may be implemented in a variety of applications, including but not limited to whole body radiation contamination detectors, laundry radiation scanners, tool/article radiation detectors, and the like.

Abstract: A small anode germanium well (SAGe well) radiation detector system/method providing for low capacitance, short signal leads, small area bottom-oriented signal contacts, enhanced performance independent of well diameter, and ability to determine radiation directionality is disclosed. The system incorporates a P-type bulk germanium volume (PGEV) having an internal well cavity void (IWCV). The external PGEV and IWCV surfaces incorporate an N+ electrode except for the PGEV external base region (EBR) in which a P+ contact electrode is fabricated within an isolation region. The PGEV structure is further encapsulated to permit operation at cryogenic temperatures. Electrical connection to the SAGe well is accomplished by bonding or mechanical contacting to the P+ contact electrode and the N+ electrode. The EBR of the PGEV may incorporate an integrated preamplifier inside the vacuum housing to minimize the noise and gain change due to ambient temperature variation.

Abstract: A spatially-aware radiation probe system/method allowing for detection and correction of radiation readings based on the position and/or movement of a radiation detector is disclosed. The system incorporates a radiation detector combined with a spatially-aware sensor to permit detection of spatial context parameters associated with the radiation detector and/or object being probed. This spatial context information is then used by analysis software to modify the detected radiation values and/or instruct the radiation probe operator as to appropriate measurement activity to ensure accurate radiation measurements. The spatially-aware sensor may include but is not limited to: distance sensors to determine the distance between the radiation detector and the object being monitored; accelerometers integrated within the radiation detector to detect movement of the radiation detector; and/or axial orientation sensors to determine the axial orientation of the radiation detector.

Abstract: A surface contamination monitoring system/method configured to correct the detected the radioactive net count rate (NCR) value of a whole-body surface contamination monitoring device based on monitored subject height and thickness is disclosed. The system includes a height detection means for determining the height of a monitored subject and a thickness detection means for determining the thickness of at least a portion of the monitored subject. The net count rate (NCR) is corrected based on the determined height and thickness of the monitored subject as applied to site calibration factor data and self-shielding factor data to produce a corrected net count rate (CNR). If the corrected net count rate (CNR) registers above a preset alarm threshold, the monitored subject is considered contaminated and an appropriate alarm is registered.

Abstract: A radiation detector system and method that significantly reduces the cost of conventionally constructed radiation detectors is disclosed. The disclosed system generally comprises an injection molded detector body incorporating plastic material with embedded feed-thrus that are encapsulated within the detector body. This detector body is mated to a detector window assembly using a gasket or other means of sealing to inhibit gas leakage. The mating methodology between the detector body and the detector window assembly is by means of plastic snap-on tabs in these structures that permit semi-permanent mating while also allowing the structures to be easily disassembled for repair and maintenance. The present invention system/method permits a significant hardware cost reduction as compared to conventional prior art radiation detector construction methodologies.

Abstract: A radiation detector system/method that simultaneously detects alpha/beta, beta/gamma, or alpha/beta/gamma radiation, within an integrated detector is disclosed. The system incorporates a photomultiplier tube with radiation scintillation materials to detect alpha/beta/gamma radiation. The photomultiplier tube output is then shape amplified and fed through discriminators to detect the individual radiation types. The discriminator outputs are fed to anti-coincidence and pulse width and timing analysis module that determines whether individual alpha/beta/gamma pulses are valid and should be counted by corresponding alpha/beta/gamma pulse radiation counters. The system may include a radiation detection method to affect alpha/beta/gamma radiation detection in a variety of contexts. The system/method may be implemented in a variety of applications, including but not limited to whole body radiation contamination detectors, laundry radiation scanners, tool/article radiation detectors, and the like.

Abstract: A spatially-aware radiation probe system/method allowing for detection and correction of radiation readings based on the position and/or movement of a radiation detector is disclosed. The system incorporates a radiation detector combined with a spatially-aware sensor to permit detection of spatial context parameters associated with the radiation detector and/or object being probed. This spatial context information is then used by analysis software to modify the detected radiation values and/or instruct the radiation probe operator as to appropriate measurement activity to ensure accurate radiation measurements. The spatially-aware sensor may include but is not limited to: distance sensors to determine the distance between the radiation detector and the object being monitored; accelerometers integrated within the radiation detector to detect movement of the radiation detector; and/or axial orientation sensors to determine the axial orientation of the radiation detector.

Abstract: A system and method for correcting, based on a monitored subject's height and thickness, the net count rate value of a whole-body surface contamination monitoring device. The device includes a height detection means for determining the height of a subject being monitored, and a thickness detection means for determining the thickness of at least a portion of the body of the subject being monitored. The net count rate is based on site calibration factor data and self-shielding factor data, wherein both types of factor data consider the determined height and thickness.

Abstract: A radiation analysis system/method that automatically optimizes the efficiency calibration of a counting system based on benchmark data and variable parameters associated with radiation source/sensor/environment (RSSE) combinations is disclosed. The system/method bifurcates RSSE context (SSEC) model parameters into WELL-KNOWN (fixed) parameters (WNP) and NOT-WELL-KNOWN (variable) parameters (NWP). The NWP have associated lower/upper limit values (LULV) and a shape distribution (LUSD) describing NWP characteristics. SSEC models are evaluated using randomized statistical NWP variations or by using smart routines that perform a focused search within the LULV/LUSD to generate model calibration values (MCV) and calibration uncertainty values (UCV) describing the overall SSEC efficiencies. Sensor measurements using the MCV/UCV generate a measurement value and uncertainty estimation value.

Abstract: A surface contamination monitoring system/method configured to correct the detected the radioactive net count rate (NCR) value of a whole-body surface contamination monitoring device based on monitored subject height and thickness is disclosed. The system includes a height detection means for determining the height of a monitored subject and a thickness detection means for determining the thickness of at least a portion of the monitored subject. The net count rate (NCR) is corrected based on the determined height and thickness of the monitored subject as applied to site calibration factor data and self-shielding factor data to produce a corrected net count rate (CNR). If the corrected net count rate (CNR) registers above a preset alarm threshold, the monitored subject is considered contaminated and an appropriate alarm is registered.

Abstract: A radiation analysis system/method that automatically optimizes the efficiency calibration of a counting system based on benchmark data and variable parameters associated with radiation source/sensor/environment (RSSE) combinations is disclosed. The system/method bifurcates RSSE context (SSEC) model parameters into WELL-KNOWN (fixed) parameters (WNP) and NOT-WELL-KNOWN (variable) parameters (NWP). The NWP have associated lower/upper limit values (LULV) and a shape distribution (LUSD) describing NWP characteristics. SSEC models are evaluated using randomized statistical NWP variations or by using smart routines that perform a focused search within the LULV/LUSD to generate model calibration values (MCV) and calibration uncertainty values (UCV) describing the overall SSEC efficiencies. Sensor measurements using the MCV/UCV generate a measurement value and uncertainty estimation value.

Abstract: A large area SDD detector having linear anodes surrounded by steering electrodes and having an oblong, circular, hexagonal, or rectangular shape. The detectors feature stop rings having a junction on the irradiation side and an ohmic contact on the anode side and/or irradiation side. The irradiation and anode stop ring biasing configuration influences the leakage current flowing to the anode and, hence, the overall efficiency of the active area of the detector. A gettering process is also described for creation of the disclosed SDD detectors. The SDD detector may utilize a segmented configuration having multiple anode segments and kick electrodes for reduction of the detector's surface electric field. In another embodiment, a number of strip-like anodes are linked together to form an interdigitated SDD detector for use with neutron detection. Further described is a wraparound structure for use with Ge detectors to minimize capacitance.

Abstract: A system for determining the calibration factor uncertainty of a radiation sensor. A computing device accepts a mathematical model of the sensor, sample, and other items affecting the calibration factor, wherein each known mathematical model parameter is assigned its normal dimensions or values and each not-well-known parameter is assigned a variable with an upper and lower limit, and a shape parameter that describes the parameter may vary within or about the limits. Random values consistent with the upper and lower limits and shape parameters for each of the variable parameters in the model are then selected, to create a mathematical model of one possible variation of source-detector measurement configuration. The selection and calibration factor computation are then repeated a large number of times and statistical parameters describing the calibration factor and uncertainty are then computed. Another embodiment performs the steps at different energies for spectroscopic detectors.

Abstract: A method, system, and software for calculating the true coincidence summing effects for radionuclide spectroscopy analysis. A set of equations which can be implemented with a stored computer program performs calculations to correct the spectroscopic analysis data for gamma-gamma coincidence events, gamma-X-ray coincidence events, as well as gamma-annihilation photon coincidence events. The net gamma-ray, KX-ray and annihilation photon summing-out probabilities for the analytic gamma-ray is the total summing-out probability from all gamma-ray summing-out chains subtracted by the total summing-out probability from all gamma-ray sub-cascade chains involving the analytic gamma-ray. A total efficiency calculation is performed to eliminate the need for using radioactive sources to create summing specific calibration measurements and for increased accuracy.

Abstract: A method is provided for simplifying the calibration of neutron multiplicity counters. The method includes multiplicity counter dead time correction algorithms that preclude the need for extended calibration steps with known radiation sources. The algorithms include approximations that allow calculation of the counter's efficiency without knowledge of sample source activity or origin.

Abstract: A scintillation-based detection device and method for continuous monitoring of flowing liquids for the presence of radionuclides. A side-stream pipe directs a portion of the monitored liquid from the main flow transfer pipe through and/or around the detector. Within the side-stream pipe is a scintillation detector assembly, having) either a nested-cylindrical or stacked-element shape. The real-time to near real-time detection capabilities are influenced by the total surface area of the detector assembly. The detectors are operated in anti-coincidence mode to distinguish pure beta-emitters from beta-gamma emitters and from pure gamma events. A gross beta count, gross gamma count, or some combination may also be determined.

Abstract: Methods of detecting radioactivity in dynamic situations in which radiation is detected from large and small radioactive objects with at least one radiation detector as the objects pass through the field of view and combinations are made from those measurements which are either adjacent in time, from multiple detectors, or at different energies. An elevated signal is reported when an analysis of the various combinations shows an elevated signal in anyone combination. Small amounts of radioactivity can be detected even in the presence of large amounts.