C. Wallner et al., Development of a very sensitive AMS method for the detection of supernova-produced longliving actinide nuclei in terrestrial archives, NUCL INST B, 172, 2000, pp. 333-337
For a search of supernova-produced actinide atoms in terrestrial archives,
techniques for measuring minute amounts of atoms of actinides with AMS have
been developed at the Munich tandem accelerator laboratory. A large analyz
ing magnet has been installed, able to bend even the heavy transuranic ions
at the high energies achievable with our MP tandem. The final detector is
a time-of-flight and a multiple energy loss measurement which allows a near
ly background-free detection of individual actinides like Pu-244. A, effici
ent chemical preparation method has been developed for the extraction of sm
all amounts of plutonium from samples up to nearly 1 kg. Furthermore, the p
reparation of sputter cathodes, containing the final sample material, was o
ptimized for high yields of negative molecules in the Cs-sputter ion source
. The first search for supernova-originated Pu-244 in a deep sea ferromanga
nese crust has already been carried out. (C) 2000 Elsevier Science B.V. All
rights reserved.