posted October 1, 2008

Research Will Trace Presence of Nuclear Materials

 A research project at Hope College is seeking to provide new tools in the ongoing effort to assure national security, focusing on a specific area of nuclear forensics:  how to determine whether or not nuclear materials have ever been present in a particular location.

The project, led by Dr. Graham Peaslee of the Hope College faculty, has recently received a three-year, $149,000 grant from the Department of Homeland Security.  The award is through department's Domestic Nuclear Detection Office, which is seeking to enhance the nation's ability to detect and report attempts to import or transport a nuclear device, Special Nuclear Material or radiological materials intended for illicit use. Special Nuclear Materials are those elements that fission readily and can be made into a nuclear device.

The project is a fundamental research initiative that will focus on developing a method to determine whether or not common minerals have been exposed to neutron irradiation.  The approach, Peaslee noted, is based on the idea that the radiation will have affected the structure of the minerals in a way that can be measured even though they will not be radioactive.

"The primary goal of these measurements will be to assess the feasibility of using common geological materials, as well as the mineral components of common building materials, to tell whether nuclear materials have ever been nearby," said Peaslee, who is professor of chemistry and chairperson of the department, and professor of geological and environmental sciences.

The team will be starting with minerals such as quartzes, feldspars, carbonates and sulfates, testing them both before and after they have been exposed to radiation.  They will specifically study the materials' cathodoluminescence, which is the visible light that they emit when struck by a beam generated by an electron gun.

"There is ample evidence in the cathodoluminescence literature that lattice defects induced by radiation will cause specific spectral changes in certain crystalline materials, but the sensitivity of this effect for neutrons in common minerals is unknown," Peaslee said.

Peaslee noted that while the term cathodoluminescence likely sounds unfamiliar, it's something that can be generated by devices Americans have had in their homes for decades.  It's the same electron gun technology that cathode ray-tube televisions use to generate images.

The Homeland Security funding will support the Hope research through September, 2011.  In addition to Peaslee, the project will include Professor Paul DeYoung of the college's department of physics and the rest of the Hope College Nuclear Group.  The Nuclear Group has been using sophisticated experimental techniques to study radioactive nuclei for the past 14 years, and it has involved more than 60 undergraduates in this research during this time.   Hope students will be participating in this new cathodoluminescence research during both the school year and the summer for the next few years.