Hosted by Dr. Yong Yang
Department of Materials Science and Engineering and Nuclear Engineering Seminar Series
Thursday, February 16, 2017 – 1:55 p.m. – 2:55 p.m. – 125 Rhines Hall
Dr. Lin Shao
Texas A&M University (TAMU)
Standardization of Accelerator Irradiation Testing Procedures for Simulation of Neutron Induced Damage in Nuclear Materials
It is well known that currently fast reactors cannot accumulate more than 20 displacements per atom (dpa) per year in iron-base structural alloys. Currently available mixed-spectrum reactors (HFIR, ATR) in the USA cannot accumulate more than 10 dpa per year and usually less. Therefore the international radiation materials community has turned its attention to charged particle simulation techniques at vastly accelerated dpa rates as surrogates for evaluation of new alloy concepts and candidates, especially with respect to void swelling and irradiation creep. The various neutron-atypical artifacts preclude, however, an exact one-to-one ion-neutron comparison for confident near-exact prediction of swelling in a neutron environment. Claims were frequently made that predictive capability was possible, but such claims were never validated and should be taken with a grain of salt. In this talk, the most important “reactor-atypical” characteristics or “artifacts” of charged particle irradiation will be discussed. Such major artifacts include defect imbalance, pulse beam effect and carbon contamination. Standard procedures are proposed to alleviate these issues. After that, we will report our recent finding on nano-grained alloys and ODS alloys, as examples of many on-going projects at Texas A&M University.
Dr. Lin Shao is Associate Professor of Nuclear Engineering at Texas A&M University (TAMU). He received a BS degree from Peking University and Ph.D from Univ. of Houston, both in Physics. Prior to joining TAMU, he was Director Funded Postdoctoral Fellow at Los Alamos National Laboratory. Dr. Shao’s primary research interests are radiation materials science and the development of damage resistant materials. He has published four book chapters, over 180 journal papers. Currently, he is director of the accelerator laboratory at Texas A&M University, which is equipped with five accelerators with terminal voltages ranging from 10 kV to 3 MV. Dr. Shao received a Postdoctoral Distinguished Performance Award from Los Alamos National Laboratory in 2006 and the inaugural Ion Beam Modification of Materials (IBMM) Prize in 2008 for his past contribution in the ion beam field. He also received 2009 NSF career award and numerous teaching awards at TAMU. Since 2007, he has been PI or co-PI of 26 externally funded projects, with a total budget of 13 million dollars.