From the 2011 Physics Alumni Newsletter
Prof. Richard Williams and his group along with collaborators at Fisk University in Nashville, TN have begun working on a research project with important applications to homeland security. Their goal is to discover what fundamentally limits energy resolution of radiation detectors, and to use that knowledge to produce improved material (specifically SrI2:Eu) for a next-generation detector with superior capabilities for port and border security screening, nuclear nonproliferation and stewardship, and nuclear medicine. The plan is to keep the cost of these new detectors low enough so that they can serve wide-spread port security applications. They have received a $900,000 grant from the Office of Nuclear Nonproliferation Research and Development of the National Nuclear Security Administration, within the U.S. Department of Energy. The funds will support this research. The project combines the special measurement and modeling capabilities of Richard’s group with the crystal growth and characterization capabilities of the group at Fisk University headed by Professor Arnold Burger. Richard’s group includes graduate students Joel Grim and Qi Li along with Research Professor Burak Ulcer. They use ultrafast laser pulses to produce electron-hole excitations at very high density that can be chosen to isolate conditions in specific regions of a particle track, in order to study nonlinear quenching and carrier diffusion properties that are believed to account for loss of energy resolution called “nonproportionality”. They conduct numerical modeling of conditions in the particle tracks using the measured data, and this has led to a significant advance in understanding of the relation between nonproportionality and specific material parameters, particularly dipole-dipole transfer rate and carrier mobility. The Fisk University lab is a premier crystal growth facility and was co-discoverer of the superior scintillation properties of SrI2:Eu along with several national laboratories.
Last fall, Physics majors Claire McLellan, Daniel David, and Katelyn Goetz presented their research results at the Plastic Electronics Week conference in Dresden, Germany. This Conference focuses on innovation in electronics, brings together professionals both from academia and industry, and is one of the most prestigious conferences in the field. All three students work with Prof. Oana Jurchescu. Their travel to the conference was supported by the WFU Undergraduate Student Stipend for Participation in International Conference and the Physics Endowment Fund.
As well as helping to send students doing research to national and international conferences, the Physics Endowment Fund is used to support other aspects of student research and scholarship. It also supports the annual faculty and student awards and allows us to provide lunches at the career advising events for our undergraduate and graduate students. The Fund is also used to support the students who are members of our local chapter of the Society of Physics Students in their activities and events throughout the academic year. I want to give special thanks to all of you who designated the Physics Endowment Fund as part of your alumni giving. The members of the Physics Department and the university community greatly appreciate the support of our alumni.
Please come by Olin Physical Laboratory and join the fun if you can. We are looking forward to seeing you. If you can’t make it to Homecoming, please drop me a note or give me a call and tell me what you’re up to. If this letter was forwarded to you, please let us know your current address.