Publications by authors named "Craig Marianno"

Mobile radiation detection systems are used widely in remediation and nuclear security. However, their detection efficiency and thus their minimum detectable activity is not completely understood. It is recognized that the detector's velocity will affect its detection efficiency.

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Radiological emergency response may require responders to operate in contaminated environments. To provide more realistic training to these individuals, it has been proposed to disperse low amounts of short-lived radioactive material in simulated emergency scenarios. To demonstrate the applicability and safety of such activities, a limited exercise was conducted where 18F was sprayed in a small area and survey activities were executed.

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A preliminary dose assessment for an emergency response exercise using unsealed radioactive sources was performed based on conservative calculation methods. The assessment was broken into four parts: activation, distribution, exercise participation, and post-exercise monitoring. The computer code MicroShield was used to determine external exposure from the source during and after distribution.

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Urban search and rescue (USAR) dogs are valuable members of their teams and play key roles in performing successful missions. A pair of dogs can do the work of dozens of people, the dogs are able to quickly sniff around collapsed structures and zip through constricted hallways with far greater accuracy than their plodding human counterparts. While in contaminated areas, their human counterparts are afforded the benefit of personal protective equipment (PPE) to keep exposures to chemical, biological and radiological substances to a minimum; USAR dogs, on the other hand, are not.

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The Department of Nuclear Engineering at Texas A&M University currently supports exercises at Disaster City, a mock community used for emergency response training that features full-scale, collapsible structures designed to simulate various levels of disaster and wreckage. Emergency response exercises can be enhanced by using unsealed radioactive sources to simulate a more realistic response environment following an incident involving the dispersion of radioactive material. Limited exercises are performed worldwide using unsealed radioactive sources, and most of that information is not publicly available.

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Calibration sources based on the primordial isotope potassium-40 (K) have reduced controls on the source's activity due to its terrestrial ubiquity and very low specific activity. Potassium-40's beta emissions and 1,460.8 keV gamma ray can be used to induce K-shell fluorescence x rays in high-Z metals between 60 and 80 keV.

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Radiation transport simulation models can provide estimations of radiation effects such as detector response and detection capabilities. The objective of this research was to develop a methodology for quick, efficient, and effective determination of the composition of shielding materials to be used in radiation transport models. A C++ code, MatFit, was developed that used the concept of densitometry and the iterative method developed for the Spectrum Analysis by Neutron Detectors II (SAND II) computer program to estimate the elemental composition of shielding materials.

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Signal processing within a radiation detector affects detection efficiency. Currently, organizations such as private industry, the U.S.

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The ORTEC digiBASE-E (ORTEC, 801 S. Illinos Ave., Oak Ridge TN 37831) is a compact photomultiplier tube endcap designed to handle all of the necessary power and signal processing requirements of a scintillation gamma-ray detector.

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Accurate quantification of radionuclides detected during a scanning survey relies on an appropriately determined scan efficiency calibration factor (SECF). Traditionally, instrument efficiency is determined with a stationary instrument and a fixed source geometry. However, as is often the case, the instrument is used in a scanning mode where the source to instrument geometry is dynamic during the observation interval.

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