AMS measurements of South American rainwater samples

Accelerator mass spectrometry (AMS) is one of the most powerful application s of heavy-ion beams in fields not directly related to nuclear physics basi c research. The development of this highly sensitive technique at the elect rostatic accelerator of the TANDAR laboratory has recently been accomplishe d. Aiming at environmental applications of our AMS activities, we have esta blished a research program using the long-lived radioisotope Cl-36 as an at mospheric tracer, in cooperation with the AMS group of the Technical Univer sity of Munich. The subject of the investigation was the global fallout of Cl-36 and its latitudinal distribution. Precipitation samples were collecte d at different latitudes in Argentina, Chile, and Antarctic, covering a ran ge from 24 degrees S to 62 degrees S. The resulting Cl-36/Cl ratios varied from 1 x 10(-14) to 62 x 10(-14). Systematics studies of this radioisotope may provide a monitor for atmospheric releases (anthropogenic contribution) and a baseline for natural Cl-36 concentration.