Practical reactor production of Ar-41 from argon clathrate

The radionuclide Ar-41 has many ideal properties as a gas flow tracer. Howe ver, the modest cross-section of Ar-40 for thermal neutron activation makes preparation of suitable activities of Ar-41 technically difficult particul arly for low flux reactors. Argon can however be trapped in a molecular com plex called a clathrate that can then be irradiated. We prepared argon clat hrate and explored its irradiation and stability characteristics. Argon cla thrate can be used to provide gigabecquerel quantities of Ar-41 even with l ow power reactors. (C) 2000 Elsevier Science Ltd. All rights reserved.