Research Profile
Dr. Orville Bignall conducts research with two of his students, Fedrick “Nick” Reynolds, left, and Bakari Underwood, as part of the Faculty and Student Team (FaST) Program, administed by the Oak Ridge Institute for Science and Education (ORISE) for the U.S. Department of Energy. The trio had a chance to use Oak Ridge National Laboratory’s Spallation Neutron Source during their research.
Teacher and Students Focus in on World’s Most Powerful Neutron-Producing Beam
Not many people get a chance to conduct research using the world’s most powerful pulsed neutron-producing beam. Three members of the U.S. Department of Energy’s (DOE) Faculty and Student Team (FaST) had that opportunity last summer.
Dr. Orville Bignall and two of his students from Tennessee State University (TSU), Bakari Underwood and Fedrick “Nick” Reynolds, conducted characterization studies of the H- ion beam in the linear accelerator at Oak Ridge National Laboratory (ORNL). To perform these studies, they utilized wire scanners that have been placed in the different segments of ORNL’s Spallation Neutron Source (SNS). The SNS provides neutron beams that are used for scientific research and industrial development.
Bignall, an associate professor of physics at TSU, and his team measured the intensity profile across a beam of negative ions as it passed the wire scanners at speeds approximating 55 percent the speed of light. In the accumulator ring, the beam is converted into a proton beam (positive ions), after having been accelerated to speeds nearing 87 percent that of light. Upon exiting the accumulator ring, the proton beam travels down a transport line to its collision with a mercury target. The collision causes many neutrons (approximately 30 per proton) to be spalled out of the mercury. These neutrons are then used for material science research. The steering mechanism that delivers the beam from its source to the target was the focus of the FaST members’ studies.
Their research was centered on ensuring the beam’s focusing and steering mechanisms were not changed over time by problems with magnets, power supplies or other issues. Neutron-scattering has a wide variety of applications in studies of the polymers that make up the composites used in jet aircrafts, credit cards, shatter-proof windshields, weather satellites and more.
Bignall said he enjoyed the collaboration with ORNL scientists at SNS and plans to draw on some of this summer’s research in his teaching at TSU. "The FaST program has provided me with the unique opportunity to embed research into an undergraduate physics curriculum, which sees no infusion of physics research," he said. "It also gives me the opportunity to interact with some very helpful and courteous people who are willing to share their time and expertise to ensure that project goals are met and the scope of the research is broadened to whatever the new directions are that it will sustain."
Reynolds, a physics major at TSU, said, "The FaST program is an excellent opportunity for students to gain hands-on experience and a deeper understanding of how their college major relates to the world."
Underwood, also a TSU physics major, said being a first time intern it was helpful to research with a faculty member who had "the time to answer specific questions and concerns that you might have. The FaST program is an excellent program for faculty and students to work together outside of the class in a different environment."
Administered for ORNL by the Oak Ridge Institute for Science and Education, the FaST Program is a cooperative effort between the DOE Office of Science and the National Science Foundation. It is designed to provide cutting-edge research opportunities to faculty and students who are from colleges and universities that have limited research facilities or from institutions which serve populations that are underrepresented in the fields of science, engineering, and technology. For more information, see the Web site at www.scied.science.doe.gov.