The Ame2003 atomic mass evaluation

Abstract

This paper is the first of two parts presenting the result of a new evaluation of atomic masses (AME2003). In this first part we give full information on the used and rejected input data and on the procedures used in deriving the tables in the second part. We first describe the philosophy and procedures used in selecting nuclear-reaction, decay, and mass spectrometric results as input values in a least-squares evaluation of best values for atomic masses. The calculation procedures and particularities of the AME are then described. All accepted data, and rejected ones with a reported precision still of interest, are presented in a table and compared there with the adjusted values. The differences with the earlier evaluation are briefly discussed and information is given of interest for the users of this AME. The second paper for the AME2003, last in this issue, gives a table of atomic masses, tables and graphs of derived quantities, and the list of references used in both this evaluation and the NUBASE2003 table (first paper in this issue).

Isomeric states in neutron-deficientA~80–90nuclei populated in the fragmentation ofAg107Garnsworthy1, Regan2, Piétri3 et al. 2009Phys. Rev. C31161View full textAdd to dashboardCite

“…A mixing ratio of δ(E1/M2) = 1.07 is required for α tot = 3.49(18) matching the measured value or δ(E1/M2) = 0.76, α tot = 2.47 (13), to match the calculated pure E2 value [49]. It is also noteworthy that the isomeric state in 86 Tc lies in the vicinity of the proton separation energy of 1393(409) keV [50], thus raising the possibility of direct proton emission from the isomer competing with internal γ -ray decay. However, the experimental arrangement used here does not allow us to observe this possible decay mode.…”

R-matrix analysis of16O compound nucleus reactions

“…The critical excitation energy range in 16 O covers the broad range between and beyond the alpha and proton separation energies (S α = 7.16191 and S p = 12.12741 * Electronic Address: rdeboer1@nd.edu MeV respectively [4]). The complexity of the reaction mechanisms of 15 N+p and 12 C+α have made it extremely difficult to determine the reaction cross sections and subsequently the reaction rates in the specific range of stellar burning with the desired accuracy and precision.…”

Accurate mass measurements on neutron-deficient krypton isotopes

“…where A is the atomic mass number of the nucleus and u the atomic mass unit, defined as 1/12 of the mass of 12 C. The mass excesses of all known nuclides are tabulated in the AtomicMass Evaluation (AME), which takes all available experimental data as input [28]. Each nuclide can be linked to up to four other nuclides.…”

“…A detailed description of the procedure is given in Ref. [28]. Table II shows the mass excess values resulting directly from our measurements of the cyclotron frequencies, from the AME prior to the ISOLTRAP measurement [27] and those including our data.…”