The LENA Gamma-Gamma Spectrometer
The spectrometer is a composite device for the efficient measurement of very weak gamma-ray signals caused by nuclear fusion reactions in the presence of ambient radioactive "noise" from decays in the surrounding material. It consists of a high-purity Germanium, surrounded by a 16-segment NaI(Tl) annular counter and a 5-sided plastic scintillator shield. A number of conditions in energy and timing can be imposed on the signals for each nuclear radiation detection event, thereby reducing the radioactive background by orders of magnitude. The spectrometer has also been used for detecting weak radioactivity present in an old meteorite, and it could also be a useful device for measurements related to homeland security.
The Project Team: TUNL Faculty: Art Champagne, Christian Iliadis, Robert Janssens, Richard Longland