To operate a coal power plant as efficiently as possible, it's important to know how much carbon and oxygen are in the coal. To reduce fouling and slagging in boilers, it's wise to burn coal low in chlorine. To conduct the analysis, the system bombards a sample with neutrons. Fast neutrons collide with some atoms, triggering the release of gamma rays. Between pulses, thermal neutrons are captured by other atoms, causing more gamma rays to be emitted.
Detectors measure the energies of the combined gamma rays, which are unique for each element.
These gamma-ray fingerprints enable concentrations of elements such as hydrogen, carbon, oxygen, nitrogen, chlorine, sulfur, and other elements in the sample to be determined accurately. Using both fast and slow neutrons allows a greater number of common elements to be detected. Western Kentucky University researchers, led by George Vourvopoulos, have demonstrated the technique's ability to distinguish between actual and mock explosives in munitions shells in military proving grounds. They have also shown how the technique can be used to inspect pallets of rice, sugar, or coffee for cocaine and other contraband materials. Oak Ridge National Laboratory researchers are investigating whether the technique can also be used to analyze the elemental content of environmental restoration wastes destined to be incinerated.