Seminar: Scintillator Applications in Homeland Security

Abstract:

Scintillation detection systems have become widely available for vehicular and pedestrian portal monitoring and for use by first responders (fire and police personnel).  Some systems are spectroscopic; others operate as sensitive dosimeters, while others operate as directional detectors.  Some systems are stationary, while others are mobile.  These instruments all have, at their cores, scintillators and photosensors, and must operate in environments very different from those found in traditional counting/spectroscopy laboratories and physics experiments.  We will describe the radiation fields that can reasonably be expected from various sources and backgrounds, and the effects of self-shielding and shielding by vehicles, cargo, and people.  The interplay between flux reaching the detector and the output of the detector will be examined, and the implications for the properties of scintillators for these applications will be discussed.

Bio:

Zane W. Bell is a Senior Scientist at the Oak Ridge National Laboratory and an adjunct faculty member of the Clemson University Department Environmental Engineering and Earth Sciences.  He received his B.S. and M.S. in physics from Rensselaer Polytechnic Institute in 1973, his Ph.D. in experimental nuclear physics from the University of Illinois at Urbana-Champaign in 1979 and joined Oak Ridge National Laboratory in the same year.  In 1986 he received an M.S. in electrical engineering from the University of Tennessee at Knoxville.  He has performed measurements of neutron cross sections, developed fast timing electronics for nuclear measurements, and studied analog and digital pulse shape discrimination methods for distinguishing neutron events from gamma ray events in liquid organic scintillators.  He has also been engaged in nondestructive evaluation with ultrasound and filmless radiography, design and development of sensors for monitoring fissile material, design and development of nuclear instrumentation, development of neutron-detecting scintillators and semiconductors.  He has led project teams in the development of instruments for neutron detection using boron-coated diodes, boron- and gadolinium-loaded scintillators, and the Cherenkov effect.  Dr. Bell has worked with the Department of Homeland Security’s Domestic Nuclear Detection Office on the Intelligent Radiation Sensor System and Advanced Radiation Monitoring Device projects.  He has served as the ORNL representative on the Radiation Detection Panel, an advisory group to the U.S. Department of Energy, and is the author or co-author of over 60 publications and oral presentations (5 invited), and 7 patents.  He and his colleagues won a 2013 R&D 100 award for LiInSe2 neutron detecting semiconductor.  Since 2004, he has served as a senior editor for IEEE Transactions on Nuclear Science.  Dr. Bell regularly participates in International Talk Like a Pirate Day festivities each September 19.

Hosted by Professor Xiaodong Sun