Nuclear nonproliferation is of critical importance for global security.Dangerous fissile materials including highly enriched uranium and weapons-grade plutonium are especially important to detect.Active interrogation ...Nuclear nonproliferation is of critical importance for global security.Dangerous fissile materials including highly enriched uranium and weapons-grade plutonium are especially important to detect.Active interrogation techniques may result in much better sensitivity but are difficult with conventional portal monitors that rely on detecting thermal neutrons.Also,most conventional portal monitoring systems rely on ^(3)He,which has a finite and continually decreasing supply.By designing a highly segmented array of organic scintillators,we posit that we can accurately and quickly identify fissile materials,including weapons-grade plutonium and highly enriched uranium,being smuggled.We propose a new design for a fast-neutron detector that overcomes the limitations of the current generation of portal monitors.MCNP6 simulations have been performed in conjunction with the UMPBT statistical model to determine the sensitivity limitations of the proposed detector.Results suggest that the proposed detector may be 10 times more efficient than current-generation thermal neutron detectors and may be able to positively identify a 81 mg 235U source in as little as 192 seconds utilizing active interrogation techniques.展开更多
The present work deals with the integration of remote-sensing,surface-geology and gravity-survey data to improve the structural knowledge of the Tarhunah area,northwest Libya.Geological information and remote-sensing ...The present work deals with the integration of remote-sensing,surface-geology and gravity-survey data to improve the structural knowledge of the Tarhunah area,northwest Libya.Geological information and remote-sensing data provided information about the surface structure.A gravity survey was conducted to decipher the subsurface structure.The results revealed that a basin having a width of 39 to 48 km trends NE.A two-dimensional(2-D)schematic model shows that the basin gradually deepens toward the southwest.Faults determined from a horizontal gradient,tilt derivative,and Euler deconvolution show a depth range of 2.5 to 7.5 km.The integration and interpretation of the results indicate that volcanic activity was related to the tectonic activity of an anticlinal structure called the Jabal Uplift.展开更多
基金supported by the National Nuclear Security Administration(NNSA)through the Center for Excellence in Nuclear Training and University Based Research(CENTAUR)under Award No.DE-NA0003841by the U.S.Department of Energy,Office of Science,Office of Nuclear Physics,under Award No.DE-FG02-93ER40773the College of Science at Texas A&M University through Strategic Transformative Research Program(CoS STRP).
文摘Nuclear nonproliferation is of critical importance for global security.Dangerous fissile materials including highly enriched uranium and weapons-grade plutonium are especially important to detect.Active interrogation techniques may result in much better sensitivity but are difficult with conventional portal monitors that rely on detecting thermal neutrons.Also,most conventional portal monitoring systems rely on ^(3)He,which has a finite and continually decreasing supply.By designing a highly segmented array of organic scintillators,we posit that we can accurately and quickly identify fissile materials,including weapons-grade plutonium and highly enriched uranium,being smuggled.We propose a new design for a fast-neutron detector that overcomes the limitations of the current generation of portal monitors.MCNP6 simulations have been performed in conjunction with the UMPBT statistical model to determine the sensitivity limitations of the proposed detector.Results suggest that the proposed detector may be 10 times more efficient than current-generation thermal neutron detectors and may be able to positively identify a 81 mg 235U source in as little as 192 seconds utilizing active interrogation techniques.
文摘The present work deals with the integration of remote-sensing,surface-geology and gravity-survey data to improve the structural knowledge of the Tarhunah area,northwest Libya.Geological information and remote-sensing data provided information about the surface structure.A gravity survey was conducted to decipher the subsurface structure.The results revealed that a basin having a width of 39 to 48 km trends NE.A two-dimensional(2-D)schematic model shows that the basin gradually deepens toward the southwest.Faults determined from a horizontal gradient,tilt derivative,and Euler deconvolution show a depth range of 2.5 to 7.5 km.The integration and interpretation of the results indicate that volcanic activity was related to the tectonic activity of an anticlinal structure called the Jabal Uplift.
