A computer chip is in development to improve detection and surveillance for the illegal transport of nuclear materials at U.S. borders.
The development comes from a cross-disciplinary team of chemists and physicists from Washington University in St. Louis and is part of a five-year, $10 million collaboration in low-energy nuclear science led by Texas A&M University.
A novel neutron detection strategy and a related chip are now in the process of testing by Robert J. Charity, research professor of chemistry, and Lee G. Sobotka, professor of chemistry and of physics, both in Arts & Sciences.
Two dozen scientists across all partner universities will be involved in the Center for Excellence in Nuclear Training and University-based Research (CENTAUR), along with their affiliated research groups. One of the center’s major contributions will be research and development expertise related to neutron detectors, which are relevant for both basic low-energy nuclear science and nuclear security applications.
“The problem with existing neutron detectors is that they are too big to get fine position information,” Sobotka said. “They needed to be big to get the required detection efficiency. The solution is to have many — tens of thousands — of small detectors. This had not been contemplated before as it requires a signal processing stream for each of the small detectors.”
Application-Specific Integrated Circuits (ASICs) form the backbone for data processing in computers, cell phones and other electronic devices. These custom chips are made because collecting oft-repeated tasks on one chip makes the overall task faster and less expensive to replicate.
Scientists don’t typically get involved with building their own ASICs, unless there is a highly specific need for the custom processing.
Sobotka, Charity and Jon Elson, research engineer in chemistry, teamed up with long-time collaborator George Engel, a professor in the department of electrical and computer engineering at Southern Illinois University Edwardsville, to build their own ASICs starting in 2001.
The collaboration has recently upgraded two chips that they built and is making a third one honed for a different scientific task. Using the previous versions of just one of these chip designs, the Washington University group has published 25 papers, mostly on the structure of nuclei with exotic neutron-to-proton ratios.
Custom ASICs developed by this group are now used by researchers at Michigan State University, Florida State University, Louisiana State University, Oak Ridge National Laboratory, Texas A&M University and most recently the Japanese lab RIKEN.
CENTAUR researchers will use two of these chips in tandem, coupled with a particular organic crystal as their detector medium, to complete high-resolution experiments with neutrons that current detectors and signal processing electronics do not allow.