December 2, 2008
New theory of adiabaticity developed
U.S. and French scientists say they've developed a new understanding of a process called adiabaticity that's used to control atoms in magnetic resonance.
Adiabatic processes are what physicists and engineers use to control atoms in nuclear magnetic resonance spectroscopy and during magnetic resonance imaging.Researchers at Ohio State University and three French institutions -- the National Center for Scientific Research, the University of Lyon and the University of Orleans -- said their findings might eventually lead to better control of magnetic resonance imaging and higher resolution MRI diagnoses.
An adiabatic process can be visualized as one where a system is 'held tightly and slowly dragged by a controlling force from one state to the next, said Ohio State chemist Philip Grandinetti of Ohio State.
In MRI, magnetic energy holds the atoms in a patient's body in a steady state while radio waves are the controlling force that drags the atoms from one state to the next.
In a 'perfect' adiabatic process, the controlling force is moved infinitely slowly with the system's trajectory locked to the controlling force's trajectory, said Grandinetti.
The complex study appeared Nov. 25 in the early online edition of the Journal of Chemical Physics.