Radiation detection and measurement is a cross-cutting area that impacts many fundamental and applied areas of science and engineering, from fundamental explorations of matter or the observable universe to the measurement of reaction cross sections, medical diagnostics, discovery of oil, and nondestructive assay of materials made in industry.
Scintillation Detector Materials and Application Engineering
Our research on scintillation materials ranges from the discovery of new compounds to the characterization of unique properties to the incorporation of novel materials in innovative detection and imaging systems. Graduate students often grow crystals of previously unknown compositions and study the interaction of radiation with their new materials, sometimes in collaboration with national laboratory researchers. Scintillation materials that reach a more developed stage may be utilized in novel detection systems that have important applications in nuclear security and/or medical imaging. Special scintillators with the ability to precisely measure the energy of absorbed gamma radiation are critical for identifying illicit sources of radioactive materials, while scintillation detectors with faster timing response may ultimately enable earlier and more accurate diagnosis of diseases such as cancer and Alzheimer’s disease.
Semiconductor Detector Development
There are several ongoing projects in this area that span many application spaces. Current semiconductor development projects include boron nitride, lithium indium diselenide, diamond, and methylammonium lead tribromide in applications ranging from advanced multimodal sensors in Generation IV reactors to cold neutron imaging.
Neutron Instrumentation for Neutron Science Facilities
One important focus of our scintillator and semiconductor system development is to enable new instrument capabilities at neutron science facilities worldwide. There are tens of them operating and more under construction, including the European Spallation Source. One special focus is high resolution sensors for neutron imaging, working toward a goal of 1 micron spatial resolution. Other work is ongoing or has been completed on a high rate instrument for reflectometry and He-3 replacement technologies. We have close partnerships with ORNL Neutron Sciences and the Paul Scherrer Institute. ORNL, providing many beamlines between the Spallation Neutron Source and the High Flux Isotope Reactor, is a worldwide leader in neutron science. The Paul Scherrer Institute is a worldwide leader in high resolution neutron imaging.
Radiation Imaging Systems for Nuclear Materials
Ongoing or recently completed work pertains to systems that image gammas, X-rays, fast neutrons, slow neutrons, or muons. Much of the work is relevant for imaging of nuclear materials or nuclear material assemblies in an effort to detect, localize, and characterize them. Both passive and active sensing of radiation are being studied, where active sensing requires an interrogating source such as a X-ray linear accelerator or a deuterium-tritium neutron generator. ORNL is an important partner in much of this work. Another partner in this area is Varex Imaging.
Radiation Detector Data Processing and Algorithm Development
Our group also does research on the processing of the data generated from said materials and systems, as well as algorithm development relevant for detection, localization, and characterization of nuclear and radiological materials.
Researchers in this area have available to them lab and office space at UT-Knoxville in Ferris Hall, the Science and Engineering Research Facility (SERF), and the Joint Institute of Advanced Materials (JIAM).
Located on the main campus in the University’s Science and Engineering Research Facility, this center combines the resources of several departments, including Nuclear Engineering, on research projects dedicated to the development of innovative materials for state-of-the-art radiation sensors and imaging systems. The SMRC has supported graduate and undergraduate students from Nuclear Engineering, Materials Science and Engineering, Energy Science and Engineering, and Chemistry. It has extensive crystal growth facilities, as well as numerous instruments for the investigation of fundamental materials properties and the response of novel materials to radiation. The SMRC has active research projects on scintillation materials in various physical forms, including inorganic single crystals, polycrystalline ceramics, and organic plastics.
Micro-Processing Research Facility
The Micro-Processing Research Facility (MPRF) at the University of Tennessee is a UT Core Facility and housed within the Joint Institute for Advanced Materials (JIAM). The MPRF provides researchers the ability to conduct micro-processing fabrication processes. Services include optical lithography, thin film deposition, capacitively coupled reactive ion etching, and silicon-based plasma enhanced chemical vapor deposition processes. This equipment is housed in a class 100 clean room with all necessary facilities and supporting process equipment. In combination with other JIAM facilities, the MPRF provides researchers with the means to conduct cutting-edge investigations in materials science and engineering.
Radiation Imaging, DEtection, Algorithms, and Systems (Rad IDEAS) Lab
In the Rad IDEAS Lab, we have a host of gamma, neutron, and alpha sources; radiation sensor and optical components; single and multichannel nuclear electronic modules; data acquisition electronics; oscilloscopes; and high-performance multicore workstations for data acquisition, processing, and simulations. This laboratory is mainly used for new proof-of-concept-level experiments in radiation detection and imaging, or to prepare experimental systems for measurements to be conducted offsite.
Dual Hybrid Detection-Localization-Imaging (Dual Hybrid DLI) System
The Dual Hybrid Detection-Localization-Imaging (DLI) trailer contains large volumes of NaI detectors and organic scintillators built into a one dimensional coded aperture imaging array. It may be used for mobile gamma imaging and detection, mobile or stationary background measurement or gammas or neutrons, or graduate student laboratory exercises.
Other Relevant ORNL Facilities
Other relevant equipment and facilities include Associated Particle Imaging (API) Deuterium-Tritium (D-T) neutron generators; Cf-252 ionization chambers; the Nuclear Materials Identification Systems (NMIS), including laboratory and fieldable versions; portable neutron coded aperture imaging systems; other gamma ray coded aperture imaging systems; access to nuclear safeguards laboratories where uranium standards are stored; and a portal monitoring facility. Many of our students use ORNL facilities, sometimes as a major component of their research.
Varex Imaging Facility
UT owns and operates a 6/9 MV linear accelerator at a Varex Imaging facility near to Chicago O’Hare (ORD) airport. This linac may be used for experiments relevant to cargo scanning for security, industrial, or medical applications.
In 2021, facilities that will be commissioned in the new Nuclear Engineering building include a linear accelerator lab (featuring the 6/9 MV linac), D-T and Deuterium-Deuterium (D-D) generators, and accelerator-driven subcritical assemblies.