Mass measurements in the vicinity of the doubly magic waiting point 56Ni
/ Authors
A. Kankainen, V. Elomaa, T. Eronen, D. Gorelov, J. Hakala, A. Jokinen, T. Kessler, V. Kolhinen, I. Moore, S. Rahaman
and 5 more authors
M. Reponen, J. Rissanen, A. Saastamoinen, C. Weber, J. Aysto
/ Abstract
Masses of {sup 56,57}Fe, {sup 53}Co{sup m}, {sup 53,56}Co, {sup 55,56,57}Ni, {sup 57,58}Cu, and {sup 59,60}Zn have been determined with the JYFLTRAP Penning trap mass spectrometer at the Ion-Guide Isotope Separator On-Line facility with a precision of {delta}m/m{<=}3x10{sup -8}. The Q{sub EC} values for {sup 53}Co, {sup 55}Ni, {sup 56}Ni, {sup 57}Cu, {sup 58}Cu, and {sup 59}Zn have been measured directly with a typical precision of better than 0.7 keV and Coulomb displacement energies have been determined. The Q values for proton captures on {sup 55}Co, {sup 56}Ni, {sup 58}Cu, and {sup 59}Cu have been measured directly. The precision of the proton-capture Q value for {sup 56}Ni(p,{gamma}){sup 57}Cu, Q{sub (p,{gamma})}=689.69(51) keV, crucial for astrophysical rp-process calculations, has been improved by a factor of 37. The excitation energy of the proton-emitting spin-gap isomer {sup 53}Co{sup m} has been measured precisely, E{sub x}=3 174.3(10) keV, and a Coulomb energy difference of 133.9(10) keV for the 19/2{sup -} state has been obtained. Except for {sup 53}Co, the mass values have been adjusted within a network of 17 frequency ratio measurements between 13 nuclides, which allowed also a determination of the reference masses {sup 55}Co, {sup 58}Ni, and {sup 59}Cu.
Journal: Physical Review C