title: 41Ca, 14C and 10Be concentrations in coral sand from the Bikini atoll.
abstract: Activation measurements of materials exposed to nuclear bomb explosions are widely used to reconstruct the neutron flux for retrospective dosimetry. In this study the applicability of coral CaCO3 as a biogenic neutron fluence dosimeter is tested. The long-lived radioisotopes (41)Ca, (14)C and (10)Be, which had been produced in nuclear bomb explosions, are measured in several coral sand samples from the Bikini atoll at the 600 kV and 200 kV AMS facilities of ETH Zurich. Elevated concentrations of all studied isotopes are found in a sample from the crater that was initially formed by the high-yield nuclear explosion Castle Bravo in 1954 and that had been used as site for several tests afterward. The observed (14)C concentration is considered too large to originate from neutron irradiation of CaCO3 alone. The relatively low concentration of (10)Be found in the crater sample indicates that production of (10)Be during nuclear bomb testing is generally minor. A simple neutron fluence reconstruction is performed on basis of the (41)Ca/(40)Ca ratio.
authors.affiliation: Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland. Electronic address: lachner@phys.ethz.ch.
authors.forename: Johannes
authors.initials: J
authors.lastname: Lachner
authors.affiliation: Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Marcus
authors.initials: M
authors.lastname: Christl
authors.affiliation: Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Vasily
authors.initials: V
authors.lastname: Alfimov
authors.affiliation: Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Irka
authors.initials: I
authors.lastname: Hajdas
authors.affiliation: Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Kubik
authors.affiliation: Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Tim
authors.initials: T
authors.lastname: Schulze-König
authors.affiliation: Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Lukas
authors.initials: L
authors.lastname: Wacker
authors.affiliation: Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Hans-Arno
authors.initials: HA
authors.lastname: Synal
mesh_terms: D000818:Animals; D037421:Anthozoa; D001608:Beryllium / Q000032:analysis*; D002119:Calcium Carbonate / Q000737:chemistry; D008849:Micronesia; D054043:Nuclear Weapons; D011834:Radiation Monitoring; D011848:Radioactive Pollutants / Q000032:analysis*; D011868:Radioisotopes / Q000032:analysis*
chemical_list: D011848:Radioactive Pollutants; D011868:Radioisotopes; D002119:Calcium Carbonate; D001608:Beryllium
keywords: (10)Be; (14)C; (41)Ca; Bikini atoll; Low-energy Accelerator Mass Spectrometry; Neutron irradiation; Nuclear weapon tests