Abstract
The spectrometer consists of a 4″×4″ NaJ-crystal with a double lead shield — the inner one being of selected lead — and a guard anticoincidence ring in between. The apparatus is situated in a cellar covered by 3 meters of soil. The total background above 0.03 MeV is 120 cpm, being extremely stable with an intrinsic r.m.s. variation below ±2 per mil. The crystal is surrounded by a sample container of volume 1.8 liters. An energy dependent gamma detection limit (2σ) ranging between 0.3 and 0.8 dpm has been obtained. This corresponds to a maximum detectable halflife of 1.0 to 2.7× 1018 years per mole of the radioactive nuclide in the sample container. In the case of vanadium-50 (isotopic abundance 0.25%) a lower limit of the half-life was found to be 9.0×1016 and 6.9×1016 years respectively for the two modes of decay V50-EC-Ti50*-γ(1.58 MeV) — Ti50 and V50-β−-Cr50*-γ(0.78 MeV)-Cr50.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Part of this paper was reported at the Conference on Low-Level Radioactivity Measurements-Limitations and New Techniques (the Institute of Physics and the Physical Society, 5–6 July, 1965, London).
This work was supported by the Heidelberg Academy of Science. Special thanks are due to ProfessorHaxel, the director of this Institute, for his stimulating interest and to Dr. H.Rebel and Dr. G.Schatz for helpful discussions. The authors thank especially Dr. D.E.Watt for advice and assistance in procuring the vanadium sample. The authors are also grateful to Johnson, Matthey & Co., Ltd., 73/83, Hatton Gordon, London, E.C. 1 and to Unterharzer Berg- und Hüttenwerke GmbH, Herzog JuliusHütte, über Goslar, for their generosity in lending the vanadium and copper samples used in this investigation.
Rights and permissions
About this article
Cite this article
Sonntag, C., Münnich, K.O. A search for the decay of Vanadium-50 with a low-level gamma-spectrometer. Z. Physik 197, 300–308 (1966). https://doi.org/10.1007/BF01325946
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01325946