Cross sections for 36Cl from Ti at EP = 35-150 MeV: applications to in-situ exposure dating
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Date
2000-10
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Elsevier
Abstract
We have measured the low-energy yield of 36Cl from Ti for proton energies from 35 to 150 MeV. Thin Ti foil irradiations were performed at the Harvard University Cyclotron Laboratory and 36Cl concentrations were determined using the ANTARES AMS facility at ANSTO. Cross-sections ranged smoothly with energy from 0.32±0.05 mb at 35 MeV to 5.3±0.4 mb at 150 MeV. Results for E<110 MeV are new, while the upper region from 110 to 150 MeV agrees well with overlapping data from other studies. The in-situ production rate for 36Cl from Ti at the earth’s surface and high latitude based on this excitation function and calculations of Masarik and Reedy (normalised to the mean measured yield of 36Cl from Ca) is estimated at ∼(13±3) atoms 36Cl (g Ti yr)−1. We thus conclude that in Ti-rich, Ca-poor rocks or in typical basalts, 36Cl yield from Ti can amount to ∼5–10% of total. This is similar to the contribution from slow muon capture on 40Ca and in some cases, from thermal neutron capture on native Cl. © 2000 Elsevier Science B.V.
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Keywords
ANSTO, Protons, Irradiation, In-situ processing, Excitation, Thermal neutrons, Titanium, Calcium
Citation
Fink, D., Vogt, S., & Hotchkis, M. (2000). Cross-sections for 36Cl from Ti at Ep=35–150 MeV: applications to in-situ exposure dating. Paper presented at the 8th International Conference on Accelerator Mass Spectrometry (AMS-8), 6-10 September 1999, Vienna, Austria. In Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 172(1–4), 861-866. doi:10.1016/S0168-583X(00)00200-7