Spallation-based neutron target for direct studies of neutron-induced reactions in inverse kinematics

Reifarth, R.; Göbel, K.; Heftrich, T.; Weigand, M.; Jurado, B.; Käppeler, F.; Litvinov, Yu. A.

doi:10.1103/physrevaccelbeams.20.044701

Cited by 34 publications

(18 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The experimental developments have focused on two approaches that combine theory and experiment in order to get at the neutron capture cross-sections, the β-Oslo method (Spyrou et al, 2014(Spyrou et al, , 2017Tornyi et al, 2014;Guttormsen et al, 1987) and surrogate reactions (Escher et al, 2012), mostly (d, p) to get access to (n, γ) rates. New initiatives have also recently been proposed for direct neutron capture studies at ring experiments (Reifarth et al, 2017). This proposal is particularly challenging since the idea is to combine, for the first time, a method that couples radioactive beam with radioactive target experiments.…”

Section: Experimental Developments For R-process Studiesmentioning

confidence: 99%

“…Recently a new method has been proposed for the direct study of neutron capture on short-lived nuclei, using high intensity radioactive beams in a storage ring on a thermalized neutron target gas produced on-line by proton-induced spallation reactions. (Reifarth et al, 2017). The cross section of the neutron capture reactions would be measured in inverse kinematics, detecting the heavy ion recoils in the ring, using for example the Schottky method developed at the GSI storage ring facilities (Nolden et al, 2011).…”

Section: N-capture In Ring Experimentsmentioning

confidence: 99%

See 1 more Smart Citation

Origin of the Heaviest Elements: the Rapid Neutron-Capture Process

Cowan,

Sneden,

Lawler

et al. 2019

Preprint

View full text Add to dashboard Cite

The production of about half the heavy elements (beyond Fe and Ni) found in nature is assigned to a specific astrophysical nucleosynthesis process: the rapid neutron capture process (r process). Although this idea has been postulated more than six decades ago, the full understanding faces two types of uncertainties/open questions: (a) The nucleosynthesis path in the nuclear chart runs close to the neutron-drip line, where presently only limited experimental information is available, and one has to rely strongly on theoretical predictions for nuclear properties. (b) While for many years the occurrence of the r process has been associated with supernovae, where the innermost ejecta close to the central neutron star were supposed to be neutron-rich, more recent studies have cast substantial doubts on this environment. Possibly only a weak r process, not producing

show abstract

Section: Experimental Developments For R-process Studiesmentioning

confidence: 99%

Section: N-capture In Ring Experimentsmentioning

confidence: 99%

Origin of the Heaviest Elements: the Rapid Neutron-Capture Process

Cowan,

Sneden,

Lawler

et al. 2019

Preprint

View full text Add to dashboard Cite

show abstract

“…The use of a storage ring enables an efficient use of the rare isotopes, and provides the highest possible luminosity of the rare-isotope beam. Initial studies of this kind have recently been published by Reifarth et al [241,242] and Glorius et al [243], using either a reactor or a spallation target to provide the neutron source. These studies will be outlined and discussed in the following.…”

Section: Approaches For Direct Measurements Of Neutron-induced Reactimentioning

confidence: 99%

Novel techniques for constraining neutron-capture rates relevant for r-process heavy-element nucleosynthesis

Larsen

Spyrou

Liddick

et al. 2019

Progress in Particle and Nuclear Physics

View full text Add to dashboard Cite

The rapid-neutron capture process (r process) is identified as the producer of about 50% of elements heavier than iron.This process requires an astrophysical environment with an extremely high neutron flux over a short amount of time (∼ seconds), creating very neutron-rich nuclei that are subsequently transformed to stable nuclei via β − decay. In 2017, one site for the r process was confirmed: the advanced LIGO and advanced Virgo detectors observed two neutron stars merging, and immediate follow-up measurements of the electromagnetic transients demonstrated an "afterglow" over a broad range of frequencies fully consistent with the expected signal of an r process taking place. Although neutronstar mergers are now known to be r-process element factories, contributions from other sites are still possible, and a comprehensive understanding and description of the r process is still lacking. One key ingredient to large-scale r-process reaction networks is radiative neutron-capture (n, γ) rates, for which there exist virtually no data for extremely neutronrich nuclei involved in the r process. Due to the current status of nuclear-reaction theory and our poor understanding of basic nuclear properties such as level densities and average γ-decay strengths, theoretically estimated (n, γ) rates may vary by orders of magnitude and represent a major source of uncertainty in any nuclear-reaction network calculation of rprocess abundances. In this review, we discuss new approaches to provide information on neutron-capture cross sections and reaction rates relevant to the r process. In particular, we focus on indirect, experimental techniques to measure radiative neutron-capture rates. While direct measurements are not available at present, but could possibly be realized in the future, the indirect approaches present a first step towards constraining neutron-capture rates of importance to the r process.

show abstract

“…the CRYRING at GSI/FAIR [90] or the CSR at MPK/Heidelberg [91]. The neutron target could be either a reactor coupled with the storage ring to obtain an interaction zone near the core [92] or the moderator surrounding a spallation target [93]. Different materials with low neutron-absorbing cross sections like D 2 O, Be or C are suited [94].…”

Section: Inverse Kinematicsmentioning

confidence: 99%

Neutron-induced cross sections -- from raw data to astrophysical rates

Reifarth,

Erbacher,

Fiebiger

et al. 2019

Preprint

Self Cite

View full text Add to dashboard Cite

Neutron capture cross sections are one of the most important nuclear inputs to models of stellar nucleosynthesis of the elements heavier than iron. The activation technique and the time-of-flight method are mostly used to determine the required data experimentally. Recent developments of experimental techniques allow for new experiments on radioactive isotopes. Monte-Carlo based analysis methods give new insights into the systematic uncertainties of previous measurements. We present an overview over the state-of-the-art experimental techniques, a detailed new evaluation of the 197 Au(n,γ) cross section in the keV-regime and the corresponding re-evaluation of 63 more isotopes, which have been measured in the past relative to the gold cross section.

show abstract

Spallation-based neutron target for direct studies of neutron-induced reactions in inverse kinematics

Cited by 34 publications

References 25 publications

Origin of the Heaviest Elements: the Rapid Neutron-Capture Process

Origin of the Heaviest Elements: the Rapid Neutron-Capture Process

Novel techniques for constraining neutron-capture rates relevant for r-process heavy-element nucleosynthesis

Neutron-induced cross sections -- from raw data to astrophysical rates

Contact Info

Product

Resources

About