Ryan Ringle

Bio: Ryan Ringle is an academic researcher from Michigan State University. The author has contributed to research in topics: Penning trap & Ion trap. The author has an hindex of 28, co-authored 112 publications receiving 2220 citations. Previous affiliations of Ryan Ringle include TRIUMF & Michigan Technological University.

First Penning-trap mass measurement of the exotic halo nucleus 11Li.

Abstract: In this Letter, we report a new mass for {sup 11}Li using the trapping experiment TITAN at TRIUMF's ISAC facility. This is by far the shortest-lived nuclide, t{sub 1/2}=8.8 ms, for which a mass measurement has ever been performed with a Penning trap. Combined with our mass measurements of {sup 8,9}Li we derive a new two-neutron separation energy of 369.15(65) keV: a factor of 7 more precise than the best previous value. This new value is a critical ingredient for the determination of the halo charge radius from isotope-shift measurements. We also report results from state-of-the-art atomic-physics calculations using the new mass and extract a new charge radius for {sup 11}Li. This result is a remarkable confluence of nuclear and atomic physics.

First use of high charge states for mass measurements of short-lived nuclides in a Penning trap.

Abstract: Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, using the TITAN facility at TRIUMF. Compared to singly charged ions, this provides an improvement in experimental precision that scales with the charge state $q$. Neutron-deficient Rb isotopes have been charge bred in an electron beam ion trap to $q=8\ensuremath{-}12+$ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly charged ions at a radioactive beam facility opens the door to unrivaled precision with gains of 1--2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed $\ensuremath{\beta}$ emitter $^{74}\mathrm{Rb}$ (${T}_{1/2}=65\text{ }\text{ }\mathrm{ms}$). The determination of its atomic mass and an improved ${Q}_{EC}$ value are presented.

The on-line charge breeding program at TRIUMF's Ion Trap For Atomic and Nuclear Science for precision mass measurements.

Abstract: TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) constitutes the only high precision mass measurement setup coupled to a rare isotope facility capable of increasing the charge state of short-lived nuclides prior to the actual mass determination in a Penning trap. Recent developments around TITAN's charge breeder, the electron beam ion trap, form the basis for several successful experiments on radioactive isotopes with half-lives as low as 65 ms and in charge states as high as 22+.

Experiments with thermalized rare isotope beams from projectile fragmentation: a precision mass measurement of the superallowed beta emitter 38Ca.

Abstract: The mass of the short-lived radio nuclide {sup 38}Ca (T{sub 1/2}=440 ms) has been measured with the 9.4-T Penning trap mass spectrometer of the Low-Energy Beam and Ion Trap Facility. A mass uncertainty of {delta}m=280 eV has been achieved, corresponding to {delta}m/m=8x10{sup -9}. The result makes {sup 38}Ca, a superallowed beta emitter, a new candidate to test the conserved-vector-current hypothesis. The experiment is also the first demonstration that short-lived radioactive isotopes produced by projectile fragmentation of relativistic heavy-ion beams can be slowed down and prepared such that precision experiments of this kind are possible.

Precision mass measurements of rare isotopes near N=Z=33 produced by fast beam fragmentation

Abstract: Mass measurements of $^{63,64}\mathrm{Ga}$, $^{64,65,66}\mathrm{Ge}$, $^{66,67,68}\mathrm{As}$ and $^{69}\mathrm{Se}$ performed at the LEBIT facility at the NSCL by Penning trap mass spectrometry are presented. The rare isotopes were produced by fast beam fragmentation and in-flight separation, then converted to a low energy beam using a gas stopping technique. Masses of the $N=Z$ nuclei $^{66}\mathrm{As}$ and $^{64}\mathrm{Ge}$ have been determined with uncertainties of $\ensuremath{\delta}\mathrm{m}/\mathrm{m}=5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}$ and $6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$, respectively, representing a more than ten-fold improvement in precision over previous measurements. For $^{63,64}\mathrm{Ga}$, $^{65,66}\mathrm{Ge}$, $^{67,68}\mathrm{As}$, and $^{69}\mathrm{Se}$ relative mass uncertainties of $\ensuremath{\delta}\mathrm{m}/\mathrm{m}l5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ were obtained. $^{69}\mathrm{Se}$ is found to be 135 keV more bound than the value listed in the 2003 Atomic Mass Evaluation. Using theoretical Coulomb shift energies in combination with the experimental mass values for $^{65,66}\mathrm{Ge}$, $^{67}\mathrm{As}$, and $^{69}\mathrm{Se}$, masses for $^{65}\mathrm{As}$, $^{66,67}\mathrm{Se}$, and $^{69}\mathrm{Br}$ are predicted with an estimated uncertainty of 100 keV. These mass values, in conjunction with our measurements, were used to calculate improved effective lifetimes of the rp-process waiting point nuclei $^{64}\mathrm{Ge}$ and $^{68}\mathrm{Se}$. We find that $^{64}\mathrm{Ge}$ is less of a waiting point while $^{68}\mathrm{Se}$ poses a larger delay in the rp-process than previously thought. The improved mass values in this region were also used to investigate the neutron-proton pairing energy of odd-odd $N=Z$ nuclei.

The jina reaclib database: its recent updates and impact on type-i x-ray bursts

Abstract: We present results from the JINA REACLIB project, an ongoing effort to maintain a current and accurate library of thermonuclear reaction rates for astrophysical applications. Ongoing updates are transparently documented and version tracked, and any set of rates is publicly available and can be downloaded via a Web interface at http://groups.nscl.msu.edu/jina/reaclib/db/. We discuss here our library V1.0, a snapshot of recommended rates for stable and explosive hydrogen and helium burning. We show that the updated reaction rates lead to modest but significant changes in full network, one-dimensional X-ray burst model calculations, compared with calculations with previously used reaction rate sets. The late time behavior of X-ray burst light curves shows significant changes, suggesting that the previously found small discrepancies between model calculations and observations may be solved with a better understanding of the nuclear input. Our X-ray burst model calculations are intended to serve as a benchmark for future model comparisons and sensitivity studies, as the complete underlying nuclear physics is fully documented and publicly available.

Annual Review of Nuclear and Particle Science

Abstract: The contents of this review reflect some of the shifts of emphasis that are occurring among the fields of astrophysics, nuclear physics, and elementary particle physics. Particle physics has made great advances in the unification of the fundamental forces of nature. Discussions and planning for a next big step in accelerator-colliders are presented. The technology of superconducting magnet systems as well as the fundamental physical principles of particle accelerators are discussed. Also presented are: high-resolution electronic particle detectors; nuclear physics changes such as pion interactions within nuclei; discussion of future relativistic heavy-ion colliders; the role of rotational degrees of freedom in heavy-ion collisions at low and moderate energies; hyperon beta decays; and the analysis of materials via nuclear reaction techniques. Neutrinos, their interactions and possible masses, have an important bearing on cosmology and the matter density of the universe in addition to their inherent interest in the microscopic world and this is also examined.