Science News Archive

A team of international researchers went back to the formation of the solar system 4.6 billion years ago to gain new insights into the cosmic origin of the heaviest elements on the periodic table.

Hot nuclear matter

A new approach gives detailed information about the spatial correlations of protons and neutrons and the size of nuclear fragments as a function of temperature and density

Varying Shapes of Selenium Isotopes

The chain of Selenium isotopes, with Z=34 protons, is thought to undergo a sudden shape change around N=36 from a disk-like to an elongated shape, which provides stringent test of nuclear structure models.

Fusion Reactions Between Neutron-rich Nuclei

Fusion reactions between neutron-rich nuclei have been proposed as a potentially important heat source in the outer-crust of an accreting neutron star, possibly triggering an X-ray superburst.

Copper-56 put on the scale

The mass measurement of 56Cu is reported, a quantity critical for understanding the reaction flow in the rapid proton capture process that fuels X-ray bursts.

Enhancement of the Triple Alpha Process

The production of carbon-12 in nature is proportional to the probability of decay of the Hoyle state to the ground state of carbon-12.

How Does Sulfur-44 Get its Spin?

A measurement performed at NSCL provided new insights into the structure of the rare isotope sulfur-44, which has an excess of 12 neutrons as compared to the most abundant stable sulfur-32 isotope found in nature.

Laser-precision studies of nuclear radii

One of the most fundamental properties of the nucleus is its size. Generally, nuclear radii follow a smooth trend: they gradually increase with the number of constituent protons and neutrons. However, when looked through a magnifying glass, measured radii display local variations, which signal structural changes. To measure such variations, superb precision is needed. To measure such small effects on radii of short-lived isotopes, a novel experimental scheme has been developed at the National Superconducting Cyclotron Laboratory at Michigan State University (MSU). The method involves laser spectroscopy of isotopes produced through a fast in-flight separation followed by gas stopping.

Bubble Nucleus Discovered at MSU

Research conducted at NSCL has shed new light on the structure of the nucleus, that tiny congregation of protons and neutrons found at the core of every atom. “The finding is somewhat unexpected,” said Alexandra Gade, chief scientist at MSU’s NSCL, where the work took place. “We’ve confirmed something that has been suspected for about 40 years but hadn’t been observed. This result furthers our understanding of how the nucleus is put together.”

A View in the Broken Nuclear Mirror

For a pair of mirror nuclei, where the number of neutrons in one matches the number of protons in the other, one expects their properties to be essentially the same. An experiment at NSCL compared an exotic mirror pair and unraveled the impact of angular momentum.

Exploding Stars and Their Elusive Nuclear Reactions

An experiment performed at NSCL on the campus of Michigan State University revealed that challenging reactions can be conquered by an indirect approach that exploits the formation of unstable nuclei in beta decay and the detection of the gamma-ray radiation liberated in the process with the SuN detector.

Tracing the Origins of Stardust in the Nuclear Physics Laboratory

Stardust from ancient stellar explosions finds its way to earth in the form of microscopic rocks called presolar grains. Identifying the origin of these grains is difficult, but a new experiment may shed some light on this 5-billion-year-old question.

Core-Collapse Supernovae to Nuclear Electron Capture

A new open source weak interaction rate library with the aim of standardizing the incorporation of weak rates in astrophysical simulations is now available. This library brings together all major weak interaction rate tables and is easily expanded to incorporate new tables of arbitrary grid resolution and ranges of density and temperature. It's first implementation was in the sensitivity study of core-collapse supernovae to nuclear electron capture.

Wigner’s Equation Passes the Test

Eugene Wigner won the 1963 Nobel Prize. Among his contributions was a simple quadratic equation known as the Isobaric Multiplet Mass Equation (IMME). Over time, questions arose about this equation. Recently, scientists were able to precisely measure nuclear structure effects at NSCL. As a result of their measurements, they showed that the IMME is revalidated.

A Radar Gun for Nuclei

Measuring the energies of the neutrons emitted following beta decay is important for applications in nuclear energy and nuclear astrophysics. However, neutrons are notoriously difficult to detect directly because they are not electrical charged. A team of scientists at NSCL recently demonstrated a technique using Doppler shift that can determine the energies of these neutrons without detecting them directly.

Discovery of Germanium 59

A team of NSCL researchers discovered the lightest known isotope of germanium: Ge-59.