Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Atomic Nuclei: Nuclear Relaxation Processes01:23

Atomic Nuclei: Nuclear Relaxation Processes

In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis,  the precessing magnetic moments are randomly oriented around the z-axis. This...
2D NMR: Overview of Heteronuclear Correlation Techniques01:18

2D NMR: Overview of Heteronuclear Correlation Techniques

Heteronuclear correlation spectroscopy is an analytical technique that investigates the coupling between different types of nuclei, often a proton and an X-nucleus, such as carbon-13 or nitrogen-15. This method is commonly used in nuclear magnetic resonance (NMR) spectroscopy to gain insights into complex chemical compounds' structural and compositional aspects. A typical heteronuclear correlation spectrum displays X-nucleus chemical shifts on one axis and a proton spectrum on the other axis.
Atomic Nuclei: Nuclear Spin01:08

Atomic Nuclei: Nuclear Spin

All atomic particles possess an intrinsic angular momentum, or 'spin'. Electrons, protons, and neutrons each have a spin value of ½, although protons and neutrons in nuclei may have higher half-integer spins owing to energetic factors.
Atomic nuclei have a net nuclear spin, , which can have an integer or half-integer value. In atomic nuclei, the spins of protons are paired against each other but not with neutrons, and vice versa. Consequently, an even number of protons does not contribute to...
Atomic Nuclei: Types of Nuclear Relaxation01:28

Atomic Nuclei: Types of Nuclear Relaxation

Nuclear relaxation restores the equilibrium population imbalance and can occur via spin–lattice or spin–spin mechanisms, which are first-order exponential decay processes.
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...
Atomic Nuclei: Nuclear Spin State Overview01:03

Atomic Nuclei: Nuclear Spin State Overview

NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...
Atomic Nuclei: Nuclear Spin State Population Distribution01:14

Atomic Nuclei: Nuclear Spin State Population Distribution

Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Porter-Thomas fluctuations in complex quantum systems.

Physical review. E·2021
Same author

Equation of State Effects in Core-Collapse Supernovae.

Physical review letters·2020
Same author

Estimating Parameter Uncertainty in Binding-Energy Models by the Frequency-Domain Bootstrap.

Physical review letters·2018
Same author

Exit-Channel Suppression in Statistical Reaction Theory.

Physical review letters·2017
Same author

Nuclear Matrix Elements for Tests of Local Lorentz Invariance Violation.

Physical review letters·2017
Same author

First Measurement of Several β-Delayed Neutron Emitting Isotopes Beyond N=126.

Physical review letters·2016

Related Experiment Video

Updated: May 22, 2026

NMR 15N Relaxation Experiments for the Investigation of Picosecond to Nanoseconds Structural Dynamics of Proteins
09:25

NMR 15N Relaxation Experiments for the Investigation of Picosecond to Nanoseconds Structural Dynamics of Proteins

Published on: November 1, 2024

Nuclear correlations and the r process.

A Arcones1, G F Bertsch

  • 1Department of Physics, University of Basel, Klingelbergstraße 82, CH-4056, Switzerland. almudena.arcones@physik.tu-darmstadt.de

Physical Review Letters
|May 17, 2012
PubMed
Summary

Long-range correlations in nuclear masses significantly impact heavy element synthesis via the r-process. Including these correlations in nuclear mass theories improves agreement with observed solar system abundances.

Area of Science:

  • Nuclear Physics
  • Astrophysics
  • Cosmochemistry

Background:

  • The rapid neutron-capture process (r-process) is responsible for synthesizing elements heavier than iron.
  • Accurate nuclear mass models are crucial for predicting r-process nucleosynthesis yields.
  • Previous models often neglected long-range correlations in nuclear masses, potentially affecting abundance predictions.

Purpose of the Study:

  • To investigate the impact of long-range correlations in nuclear masses on r-process nucleosynthesis.
  • To assess how these correlations influence the suppression of magic number effects and the resulting elemental abundances.
  • To improve the agreement between theoretical predictions and observed solar system abundances.

Main Methods:

  • Utilizing nuclear mass calculations that incorporate long-range correlations, as previously performed by Delaroche et al.

More Related Videos

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
10:52

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex

Published on: July 27, 2022

Exploring Protein-Glycan Interactions: Advances in Nuclear Magnetic Resonance
10:07

Exploring Protein-Glycan Interactions: Advances in Nuclear Magnetic Resonance

Published on: August 26, 2025

Related Experiment Videos

Last Updated: May 22, 2026

NMR 15N Relaxation Experiments for the Investigation of Picosecond to Nanoseconds Structural Dynamics of Proteins
09:25

NMR 15N Relaxation Experiments for the Investigation of Picosecond to Nanoseconds Structural Dynamics of Proteins

Published on: November 1, 2024

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
10:52

Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex

Published on: July 27, 2022

Exploring Protein-Glycan Interactions: Advances in Nuclear Magnetic Resonance
10:07

Exploring Protein-Glycan Interactions: Advances in Nuclear Magnetic Resonance

Published on: August 26, 2025

  • Analyzing the effects of these correlations on nuclear shell effects, particularly around minor shells.
  • Examining the impact on calculated elemental abundances, focusing on the region before the third r-process peak (A≈195).

    • Main Results:

    • Long-range correlations in nuclear masses significantly suppress magic number effects associated with minor shells.
    • This suppression leads to a reduction in the abundance trough observed before the third r-process peak.
    • The masses of nuclei in the deformed-spherical transition region are shown to strongly influence the trough and the third peak's position.

    Conclusions:

    • A microscopic theory of nuclear masses that includes long-range correlations naturally smoothens separation energies.
    • This improved theoretical framework reduces the abundance trough and enhances agreement with observed solar system abundances.
    • The findings highlight the importance of incorporating nuclear correlations for accurate astrophysical nucleosynthesis modeling.