KNOXVILLE, Tenn. (AP) — A retired University of Tennessee professor was indicted Tuesday on charges of conspiring to provide military secrets to a Chinese graduate student.

J. Reece Roth, 70, a professor emeritus who headed the school's Plasma Sciences Lab, faces 18 charges related to violating the Arms Export Control Act and trying to defraud the U.S. Air Force.

The charges involve work performed from 2004 to 2006 by Roth, the student and a university spinoff company for an Air Force contract to develop flight controls for unmanned aircraft, or "drones."

Prosecutors said Roth and the company he helped found, Atmospheric Glow Technologies Inc., failed to get government permission before involving foreign national Xin Dai in the work.