Abstract
USING nickel as a receiving plate for the recoil of radio-elements produced in the Fermi effect I have found, contrary to the statements of Fermi and his co-workers1, that this metal acquires a slight activity under neutron bombardment. This effect must be attributed to nickel, because it is exhibited by chemically pure nickel plates and nickel oxide. Further investigations have shown that the induced radioactivity of nickel is composed of two parts, cne decaying with a period of about 20 minutes and another with a period of the order of a few hours. The activity of both products is very small: nickel plates of 0.1 mm. thickness exposed for 12 hours to the full neutron radiation of 40 millicuries of radon mixed with beryllium give an initial effect of 1.5 impulses per minute. The long-life activity is enhanced 4–5 times, when neutrons are allowed to pass through water ; the short-period product shows no increase in this case. It is therefore probable that the first product is an isotope of nickel. The possible reactions leading to this product are: Reaction (2) is more probable since its end product would be the stable isotope 63 of copper. The small relative importance of Ni62 in nickel would account for the smallness of the effect observed.
Similar content being viewed by others
Article PDF
References
E. Fermi, E. Amaldi, O. D'Agostino, F. Rasetti, E. Segrè, Proc. Roy. Soc., A, 146, 483; 1934. 149, 522 ; 1935.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
ROTBLAT, J. Induced Radioactivity of Nickel and Cobalt. Nature 136, 515 (1935). https://doi.org/10.1038/136515a0
Issue Date:
DOI: https://doi.org/10.1038/136515a0
This article is cited by
-
Radioactive Isotopes of Copper
Nature (1937)
-
Radioactive Isotopes of Nickel and Copper
Nature (1936)
-
Induced Radioactivity of Nickel and Tin
Nature (1936)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.