Woodruff School of Mechanical Engineering

Faculty Candidate Seminar


Gallium Nitride Neutron Detector and Its Evaluation with a Collimated Neutron Beam


Dr. Lei Raymond Cao


The Ohio State University


Thursday, November 20, 2014 at 11:00:00 AM


MRDC Building, Room 4211


Chaitanya Deo


The giant leap in light-emitting diode (LED) industry toward general lighting came when the first practical bright blue LED using nitride-based compound semiconductors (e.g. GaN) was developed in mid-1990, which led to the 2014 Nobel Prize in physics. The exceptional electronics and mechanical properties observed in GaN makes it a potential candidate for radiation detection in harsh environment. When properly doped or coated with neutron-sensitive materials, GaN could be turned into an effective and inexpensive neutron detection device. We have fabricated GaN based Schottky structure sensors and have demonstrated their neutron response, using a thermal neutron beam as a high-flux testing source. We have also studied the devices’ performance in high temperature and high radiation environment, which lead to the potential applications of this sensor in a harsh radiation environment such as in nuclear reactors and/or in-pile experiments. A neutron beam facility that has been recently built at the Ohio State University Research Reactor (OSURR), which delivers a well-thermalized neutron beam with adjustable beam size from 30 mm to 1 mm, will also be introduced, including its applications for testing of other novel neutron sensors and characterizing advanced energy storage materials such as Li-ion batteries.


Dr. Lei Raymond Cao is an assistant professor in the Nuclear Engineering Program at The Ohio State University (OSU) since January 2010. Dr. Cao received his BS in Experimental Nuclear Physics from Lanzhou University in 1994, MS degree in Nuclear and Particle Physics from China Institute of Atomic Energy in 2002, and PhD degree from Nuclear and Radiation Engineering Program at the Department of Mechanical Engineering at University of Texas at Austin in 2007. Prior to joining OSU, Dr. Cao was a research associate at the Center for Neutron Research, U.S. National Institute of Standards and Technology for two and a half years. Before that, he has also received a 6-months training at the Positron Emission Tomography Laboratory at Harvard Medical School. Dr. Cao’s researches focus on nuclear instrumentation and radiation detection, semiconductor neutron sensor, radiation effects, and nuclear analytical technologies. He has published 40 journal articles and 27 conference proceedings. Dr. Cao is the Vice Chair of the Isotope and Radiation Division at the American Nuclear Society and is also an Assistant Program Chair or a technical committee member for two international conferences in his field.


Refreshments will be served.