The detection of Ni-63 (T-1/2 = 100.1 yr) by means of accelerator mass spec
trometry (AMS) using a gas-filled magnet (GFM) is described. The experiment
al setup includes a dedicated ion source, a 14 MV MP tandem, a GFM and a mu
ltianode ionization chamber. First results indicate a background level of N
i-63/Ni ratios as low as 2 x 10(-14). This sensitivity will allow - for the
first time ever - to detect Ni-63 induced by fast neutrons in copper sampl
es from Hiroshima and Nagasaki, even for distances beyond 1500 m from the h
ypocenters. Thus, it will be possible to reconstruct experimentally the neu
tron doses of the A-bomb survivors from Hiroshima and Nagasaki. (C) 2000 El
sevier Science B.V. All rights reserved.