1957/02/01 by Walter H. Johnson, A. O. Nier · 62 citations
Physics and Astronomy · #Nuclear physics research studies #Nuclear Physics and Applications #Advanced Chemical Physics Studies #Binding energy #Physics #Pairing #Atomic physics #Nuclear physics #Nucleon #Neutron #Mass number #Quadrupole
paper · doi:10.1103/physrev.105.1014
published in Physical Review 105(3), 1014-1023 (American Institute of Physics)
openalex publication_date 1957/02/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/26
A six-inch double-focusing mass spectrometer employing the peak matching method of measurement has been used to measure 36 atomic masses in the region 130\ensuremath\leqqA\ensuremath\leqq154 and 54\ensuremath\leqqZ\ensuremath\leqq63. Atomic masses of 41 radioactive nuclei have then been calculated from mass differences derived from nuclear reaction and \ensuremathβ-decay energies. Nucleon binding and pairing energies have been calculated from the resulting mass table. The effect of the shell closure at N=82 on the systematics of nuclear binding and pairing energies has been investigated in greater detail than has previously been possible. The discontinuity in neutron binding energy, observed in reaction measurements and \ensuremathβ-decay systematics, is shown to be caused by a decrease in binding energy of neutrons beyond N=82 rather than a particular large binding energy at N=82. The systematic behavior of proton binding and pairing energies is also studied. The nucleon binding and pairing energy results show departures from uniformity in the region near N=90. Electric quadrupole systematics have also indicated a change in nuclear structure in this region. The present atomic masses are also employed in the isotopic identification of several reactions, in the study of several natural alpha decays, and in the interpretation of several \ensuremathβ-decay disintegration schemes.