M. Paul et al., ENVIRONMENTAL SR-90 MEASUREMENTS, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 123(1-4), 1997, pp. 394-399
Sr-90 (T-1/2 = 28.5 years) is a long-lived radionuclide produced in nu
clear fission. Fast radiochemical detection of Sr-90 in environmental
samples is not feasible using current analytical methods. Accelerator
Mass Spectrometry (AMS) measurements of Sr-90 were made with the Rehov
ot 14UD Pelletron accelerator at a terminal voltage of 11 or 12 MV usi
ng our standard detection system, Injection of hydride ions (SrH3-) wa
s chosen owing to high beam intensity and low Coulomb explosion effect
s. Sr-90 ions were identified and discriminated from isobaric Zr-90 by
measuring time of flight, total energy and three independent energy-l
oss signals in an ionization chamber, A reference sample and a ground-
water sample were successfully measured. The detection limit determine
d for a laboratory blank by the residual counts in the Sr-90 region is
Sr-90/Sr = 3 x 10(-13), corresponding in practice to (2-4) x 10(7 90)
Sr atoms or about 0.5-1 pCi/L samples.