Synthesis of element 107

Bohrium is a chemical element in the periodic table that has the symbol Bh and atomic number 107.

“…In the first experiments on the bombardment of 209Bi by 54Cr ions we observed a spontaneously fissioning emitter with an approximate half-life 5 sec. The results of experiments with the crossing reactions 209Bi + 54Cr, 208Pb + 55M and 205Tl + 58Fe have indicated that the yield of the observed activity exhibits the same regularities that can be expected when the 107th element is produced.

…In the succeeding experiments the speed of the experimental procedure was greatly increased, and bombardment of 209Bi by 54Cr ions revealed a spontaneously fissioning emitter with T1/2 ~ 2 msec. The yield of this emitter correlated in all experiments with the yield of the long-lived activity with T1/2 ~ 5 sec, which can be regarded as the result of the spontaneous fission of the isotope 257105, produced after α decay of 261107…”

From “Experiments on the synthesis of element 107” Yu.Ts.Oganesyan, A.G.Demin, N.A.Danilov, M.P.Ivanov, A.S.Il’inov, N.N.Kolesnikov, B.N.Markov, Plotko V.M., S.P.Tretyakova and G.N.Flerov, JINR E7-9686 (1976)
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“Experimental Studies of the Formation and Radioactive Decay of Isotopes with Z=104-109” Yu.Ts.Oganessian, M.Hussonnois, A.G.Demin, Yu.P.Kharitonov, H.Bruchertseifer, O.Constantinescu, Yu.S.Korotkin, S.P.Tretyakova, V.K.Utyonkov, I.V.Shirokovsky and J.Estevez, JINR E2-84-651 (1984), p.4-7
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