Synthesis of Element 104

Rutherfordium is a chemical element in the periodic table that has the symbol Rf and atomic number 104.

“In 1964, in the Nuclear Reactions Laboratory of the Joint Institute for Nuclear Research, by the irradiation of Pu242 with accelerated Ne22 ions, nuclei were synthesized which undergo spontaneous fission with a half-life equal to 0.2 to 0.4 sec approximately. Spontaneous fission of the new emitter was detected in the decay background of spontaneously fissile isomers and other activities which are formed in significant quantities in the reaction Pu + Ne and therefore, in the first paper the half-life could not be measured accurately.

The difficulties which the experimenters encountered are illustrated by the following figures: with a maximum flux intensity of accelerated neon ions (tens of microamperes of ion current) the observed yield amounted approximately to one atom per hour. However, despite these difficulties analysis of the shape of the excitation function for the detected emitter and of the results of control experiments permitted the authors of the paper to draw the conclusion, that the isotope which had been synthesized is one of the isotopes of element 104 and, in all probability, its mass number is 260 [27]… “

From “SYNTHESIS AND SEARCH FOR HEAVY TRANSURANIUM ELEMENTS” G. N. Flerov,(p.4). Translated from Atomnaya Energiya, Vol. 28, No. 4, pp. 302-309, April, 1970.
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Zvara J., Chuburkov Yu.T., Paletka R., Shalaevskii M.R. Experiments on chemistry of Element 104. I // Radiochemistry. 1969. Vol. 11. P. 163.

Zvara J., Chuburkov Yu.T., Belov B.Z., Buklanov G.V., Zakhvataev B.B., Zvarova T.S., Maslov O.D., Paletka R., Shalaevskii M.R. Experiments on chemistry of Element 104. V // Radiochemistry. 1970. Vol. 12. P. 565;
J. Inorg. Nucl. Chem. 1970. V. 32. P. 1885.