M. Bichler J. Caggiano L.D. Cecil Masri Y. El R. Golser C.L. Jiang A. Heinz D. Henderson W. Kutschera B.E. Lehmann P. Leleux H.H. Loosli R.C. Pardo M. Paul K.E. Rehm P. Schlosser R.H. Scott W.M. Smethie Jr. R. Vondrasek P.H. Collon 2004 Initial experiments at the ATLAS facility [Nucl. Instr. and Meth. B 92 (1994) 241] resulted in a clear detection of cosmogenic 39Ar signal at the natural level. The present paper summarizes the recent developments of 39Ar AMS measurements at ATLAS: the use of an electron cyclotron resonance (ECR) positive ion source equipped with a special quartz liner to reduce 39K background, the development of a gas handling system for small volume argon samples, the acceleration of 39Ar8+ ions to 232 MeV, and the final separation of 39Ar from 39K in a gas-filled spectrograph. The first successful AMS measurements of 39Ar in ocean water samples from the Southern Atlantic ventilation experiment (SAVE) are reported. Published by Elsevier B.V. application/pdf 10.1016/j.nimb.2004.04.081 en Development of an AMS method to study oceanic circulation characteristics using cosmogenic 39Ar text