KNOXVILLE, Tenn. (AP) — A retired University of Tennessee engineering professor went on trial Monday, accused of passing secrets from his work on a U.S. Air Force contract to two foreign graduate students, one from China and the other from Iran.

J. Reece Roth, a 71-year-old expert in plasma physics, faces 18 counts of conspiracy, fraud and violating the Arms Export Control Act. He could receive up to 160 years in prison and more than $1.5 million in fines if convicted.

The law bars exchange of sensitive, though in this case not "classified," information to foreign nationals without permission.

A Knoxville company and a former protege of Roth have pleaded guilty and await sentencing.