The EAPS neutron activation laboratory does gamma-ray spectroscopy of samples subjected to a high flux of thermal neutrons in the MIT Nuclear Reactor. Most samples are analyzed by Instrumental Neutron Activation Analysis (INAA); i.e., no chemical processing is done. This approach provides precise abundance data at the parts per million level for Na, Cs, Sc, Cr, Co, Hf, Ta, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu and Th. Two important aspects of this technique are: (a) the sample is not destroyed and (b) there is no contamination of the sample by impurities in chemical reagents. The gamma ray spectroscopy is done with Ge semi-conductor detectors interfaced to multichannel analyzers, under the control of a DEC MicroVax computer using the software reduction package TEABAGS. Although a wide range of materials ranging from spec-pure graphite and SiO2 to blood serum and lichen have been analyzed, most of the samples studied are powdered rocks. In addition to INAA, precise data for a wide variety of other elements, such as platinum group metals, can be obtained by utilizing chemical procedures to isolate elements or groups of elements prior to gamma-ray spectrometry.

Under the supervision of Professor Fred Frey this facility has gradually devleoped since the mid-1970's and the most recent incremental upgrade was in 1990. Since 1980, the immediate laboratory supervisor has been Dr. P. Ila (M.S., Georgia Institute of Technology; PhD, Andhra University, India). Her formal education was in the fields of Nuclear Physics and Radiation Health Physics. She has worked in and supervised an instrumental neutron activation facility since 1976.

A major use of the facility is to support the research of Fred Frey and collaborators in their studies of volcanic rocks formed in intraplate, divergent plate and convergent plate tectonic settings. Recent research has been on Andean lavas in Chile and Argentina, and on the largest terrestrial volcanoes, (known as hotspot volcanoes) which form long, linear chains of volcanoes, e.g., Hawaii in the Pacific Ocean and Ninetyeast Ridge in the Indian Ocean. We are now participating in the Hawaiian Scientific Drilling Project which will recover a 4.5 km core through Mauna Kea Volcano. Also in 1999 we will be part of Ocean Drilling Project LEG 183 whose objective is to sample and study one of the largest submarine igneous provinces in the world- the Kerguelen Plateau. There are also a variety of other applications, e.g., in archaeology, and the facility has recently been used by researchers from the University of Massachusetts, University of Virginia, Southern Methodist University and the Woods Hole Oceanographic Institution.

To learn more about our facility, please vist the Neutron Activation web site.