![no gamma control for monitor no gamma control for monitor](https://i.ytimg.com/vi/z99akbPVzpc/maxres2.jpg)
The gamma monitor also provides a permanent record of the daily performance of each ion exchange system. The real-time data obtained from an operating process allow operators to optimize many process parameters. The short half-life and 208-keV gamma energy of /sup 237/U make it an ideal radiotracer to mark the position of macro amounts of uranium impurity in the separation process. However, a small fraction of /sup 241/Pu decays by alpha emission to 6.8-day /sup 237/U. Plutonium-241, which is always present in plutonium processed at Los Alamos, decays primarily by beta emission to form /sup 241/Am. Because natural and depleted uranium present in typical process streams have no gamma rays suitable for measurement by such passive methods, uranium measurement requires a novel and less direct technique. The gamma monitor employs passive gamma spectrometry to measure /sup 241/Am and /sup 239/Pu, based on their 59.5-keV and 129-keV gamma rays, respectively. An on-line gamma monitor has been developed to profile uranium, plutonium, and americium in waste and product streams of the anion exchange process used to recover and purify plutonium at the Los Alamos Plutonium Facility.