RECENT ON-SITE GAMMA MEASUREMENTS AT THE TRINITY TEST SITE AND A COMPARISON TO TRINITITE SAMPLES

Year
2011
Author(s)
David J. Mercer - Los Alamos National Laboratory
Phillip A. Hypes - Los Alamos National Laboratory
Paul R. J. Saey - Division of Safegaurds, International Atomic Energy Agency
Abstract
The world’s first nuclear device was detonated on 16 July 1945 near Alamogordo, New Mexico. The device, called “The Gadget,” was placed on a 100-foot-tall steel tower and detonated with a yield of about 20 kilotons. The desert soil was drawn into the fireball, was melted and mixed with radioactive debris, and then rained down to form a green glass that would be named “Trinitite.” This material was heavily scavenged by mineral collectors, and in 1952 most of the remaining material in the crater was bulldozed and buried. Visible particles of Trinitite near ground zero are very sparse; however, the soil still retains some radioactivity. During a recent visit to the site, we collected spectra at several locations near ground zero using a mechanically cooled high-resolution gamma spectroscopy system. We report results from these measurements, as well as laboratory measurements of Trinitite samples and glass samples obtained from nuclear detonation sites in Nevada and Semipalatinsk.