Discovery of zinc, selenium, bromine, and neodymium isotopes

Abstract

Currently, thirty-two zinc, thirty-two selenium, twenty-nine bromine and thirty-one neodymium isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.[119]. A 40 Ca beam from the Berkeley SuperHILAC bombarded a gas-cooled 92 Mo target. 127 Nd was produced in the fusion-evaporation reaction 92 Mo( 40 Ca,αn) and identified with the on-line isotope separator OASIS. "From the growth and decay data, a half-life of 1.9 ± 0.4 s was deduced, which is in good agreement with the calculated value of 1.8 s for 127 Nd." This half-life is included in the currently accepted average value of 1.8(4) s. 128 NdIn 1985 128 Nd was identified by Lister et al. in "Deformation of Very Light Rare-Earth Nuclei" [120]. A 40 Ca beam from the Daresbury Laboratory Van de Graaff accelerator was incident on a 92 Mo target and 128 Nd was produced in the fusion-evaporation reaction 92 Mo( 40 Ca,2p2n). Gamma rays, neutrons and charged particles were detected and new ground-state bands observed. "This letter reports results on the ground-state bands in the even-even nuclei 128 ." An earlier identification and half-life measurement of 4(2) s [119] was later refuted [121]. 5.4. 129−133 Nd The first identification of 129 Nd, 130 Nd, 131 Nd, 132 Nd, and 133 Nd, was reported in 1977 by Bogdanov et al. in "New Neutron-Deficient Isotopes of Barium and Rare-Earth Elements" [122]. The Dubna U-300 Heavy Ion Cyclotron accelerated a 32 S beam which bombarded enriched targets of 102 Pd and 106 Cd. The isotopes were identified with the BEMS-2 isotope separator. "In the present paper, isotopes were mainly identified by measuring the γ-ray and X-ray spectra of the daughter nuclei formed as a result of measuring the β + decay. In addition, the decay curves of the total β-activity of given isobars have been measured." The reported half-life of 5.9(6) s for 129 Nd is close to the accepted value of 4.9(2) s. The half-life of 28(3) s for 130 Nd is within a factor of two of the currently accepted value of 13(3) s. The half-lives of 24(3) s ( 131 Nd) and 105(10) s ( 132 Nd) are included in the currently accepted average values of 25.4(9) s and 94(8) s. The half-life of 70(10) s for 133 Nd corresponds to the presently adopted half-life. 5.5. 134,135 Nd 134 Nd and 135 Nd were discovered by Abdurazakov et al. in the 1970 paper "New Isotopes 133 Pr, 134 Nd, and 135 Nd; Decay Schemes of 134 Pr and 135 Pr" [123]. Spallation reactions were induced by 660 MeV protons irradiating a gadolinium target at the Joint Institute for Nuclear Reactions in Dubna, Russia. The reaction products were then chemically separated and identified by the measured γ-ray spectra. " 134 Nd was identified and its half-life determined via the strongest γ rays of 134 Pr (T = 17±2 min) with energies 409.2 and 639.0 keV.[The figure] shows the build-up and decline of the intensity of the 409.2 keV γ lray of 134 Pr. The half-life of was found from the...

Current status and future potential of nuclide discoveries

“…Although not impossible it is unlikely that further nuclides will exist for which characteristic resonance parameters can be measured. 63 Se not measured 35 68 Br not measured, but 69 Br unbound 36 68 Kr not measured 37 72 Rb not measured, but 73 Rb unbound 38 72 Sr not measured 39 75 Y not measured 40 77 Zr not measured 41 81 Nb Z. Janas 1999 GANIL [150] 42 82 Mo not measured 43 85 Tc Z. Janas 1999 GANIL [150] For neutron rich nuclei characteristic properties of at least two isotopes beyond the neutron dripline have been identified for the lightest elements, hydrogen, helium and lithium. Neutron rich nuclides between beryllium and magnesium which have been shown or expected to be unbound but have not been observed are listed in Table 5.…”

Comparison of the Application of High-Resolution Inductively Coupled Plasma Mass Spectrometry (HR-ICP-MS) and Collision/Reaction Cell Technology of Inductively Coupled Plasma Mass Spectrometry (ICP-CCT-MS) in the Determination of Selenium in Coal-Bearing Strata

“…Selenium has six natural isotopes with relative atomic masses of 74, 76, 77, 78, 80, and 82 [24,51,61,62]. These isotopes can be subject to various interferences during mass spectrometry analysis, which can be categorized into diatomic ion interferences, isobar interferences, and doubly charged ion interferences (Table 5).…”

Selenium in natural environment and food chains. A Review

“…al., 2009). In nature, a significant number of selenium isotopes are known, six of which are stable, with the following prevalence: 74 Se (0.87% by mass), 76 Se (9.02 %), 77 Se (7.58 %), 78 Se (23.52 %), 80 Se (49.82 %) and 82 Se (9.19 %), and the remaining twenty-six are radioactive, with different half-lives, in the range of mass numbers from 64 to 95 (Gross et. al., 2012).…”