Preliminary Report on the Radioactivity Produced in Y, Zr, and Mo

Discovery of gallium, germanium, lutetium, and hafnium isotopes

“…While the possibility of isomorphism cannot be overlooked, the identification of Ge 69 seems reasonable." The reported half-life agrees with the currently accepted value of 39.05(10) h. No reference to the 26 h half-life reported by Sagane was given in the paper, but it probably refers to reference [64]. However, in that paper, Sagane assigned this half-life to 71 Ge, reporting a half-life of 30 min for 69 Ge.…”

“…60 70 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020 Year Discovered protons from the Tokyo synchrocyclotron bombarded a natural zinc target. 62 Ga was produced in the reaction 64 Zn(p,3n) and β-activities were measured with a plastic scintillator. "The obtained data points were analyzed with a least squares fitting program by taking into account the following three components: a 20-msec 12 B, an unknown 62 Ga, and a constant long lived background activity.…”

“…Protons from the Oak Ridge 86-in. cyclotron bombarded enriched 64 Zn targets and 64 Ga was produced in the (p,n) charge exchange reaction. Gamma-ray spectra…”

“…62 Ge and 63 Ge were identified by measuring the rigidity, ∆E, E total , and velocity in the A1200 fragment separator. "Several new isotopes at or near the proton-drip line are indicated in the mass spectra: 61 Ga, 62 Ge, 63 Ge, 65 As, 69 Br, and 75 Sr." 64 Ge." These half-lives agree with the presently adopted values of 63.7(25) s and 30.9(5) s for 64 Ge and 65 Ge, respectively.…”

“…"Several new isotopes at or near the proton-drip line are indicated in the mass spectra: 61 Ga, 62 Ge, 63 Ge, 65 As, 69 Br, and 75 Sr." 64 Ge." These half-lives agree with the presently adopted values of 63.7(25) s and 30.9(5) s for 64 Ge and 65 Ge, respectively. The previously reported half-life of 65 Ge mentioned in the quote (1.5(2) min) was evidently incorrect [60] and an earlier attempt to observe 64 Ge was unsuccessful [61].…”