Exploring Nuclear Reactions in Exploding Stars and the Origin of Aluminum-26

 

International Conference on Nuclear Physics


Scientists from the University of Surrey and the FRIB Laboratory at MSU teamed up to explore the origin of aluminum-26, a rare isotope that offers a window into dying stars. Their findings, “Exploiting Isospin Symmetry to Study the Role of Isomers in Stellar Environments,” were published in Physical Review Letters.





Aluminum-26 provides rare insight into processes in stars. It decays into magnesium-26, which emits a characteristic gamma ray observable with satellites. Magnesium-26 is detectable in presolar grains of material from stars that existed before the sun. The composition of these grains carries the fingerprints of their parent stars. The destruction rate of aluminum-26 by capturing a proton is critical for interpreting the amount of magnesium-26 observed in the universe. This research showed that the destruction of aluminum-26 by proton capture on the long-lived state is eight times less frequent than previously estimated.


Gavin Lotay, senior lecturer and director of learning and teaching at the University of Surrey, was the project’s spokesperson. Alexandra Gade, professor of physics at FRIB and in MSU’s Department of Physics and Astronomy and FRIB deputy scientific director, led part of the MSU collaboration.


Aluminum-26 has a long-lived quantum state that is difficult to study in a controlled way in the laboratory. The team used a transfer reaction that added a neutron to the radioactive isotope silicon-26 to study excited quantum states in silicon-27. These are the same states that are populated in the proton capture on the long-lived quantum state of aluminum-26. This was possible because protons and neutrons are subject to a symmetry that makes adding a proton to the long-lived state in aluminum-26 equivalent to adding a neutron to the ground state of silicon-26. The measurement used the Gamma-Ray Energy Tracking In-beam Nuclear Array (GRETINA), a national resource, and the laboratory’s S800 Spectrograph.

This research stems from a longstanding collaboration between the FRIB Laboratory and the University of Surrey, where direct nuclear reactions are used to populate quantum states whose exact energies and properties are of relevance to reactions that happen in stars. The staple of the collaboration has been the use of very sensitive gamma-ray spectroscopy to tag and characterize the excited quantum states of interest. Lotay eagerly anticipates the start of science at FRIB to further his research. He has submitted three proposals for beam time at FRIB that will be considered by the first FRIB Program Advisory Committee later this summer.



“We have now reached a truly exciting time in science, where we are able to directly probe the processes that occur in exploding stars,” said Lotay. “These celestial objects are responsible for the rich variety of chemical elements we find all around us and, by coupling gamma-ray spectroscopy with direct reaction techniques, the collaboration has been successful in obtaining key information needed to understand their properties. The collaboration is now poised to significantly expand the scope of its nuclear astrophysics program and capitalize on the vast swathe of opportunities available at the soon-to-open FRIB facility.”

Reference: “Exploiting Isospin Symmetry to Study the Role of Isomers in Stellar Environments” by S. Hallam, G. Lotay, A. Gade, D. T. Doherty, J. Belarge, P. C. Bender, B. A. Brown, J. Browne, W. N. Catford, B. Elman, A. Estradé, M. R. Hall, B. Longfellow, E. Lunderberg, F. Montes, M. Moukaddam, P. O’Malley, W.-J. Ong, H. Schatz, D. Seweryniak, K. Schmidt, N. K. Timofeyuk, D. Weisshaar and R. G. T. Zegers, 29 January 2021, Physical Review Letters.
DOI: 10.1103/PhysRevLett.126.042701

This research was funded by the U.S. Department of Energy (DOE) Office of Science Office of Nuclear Physics; the National Science Foundation; and the DOE National Nuclear Security Administration through the Nuclear Science and Security Consortium and the Science and Technologies Facilities Council of the United Kingdom.

#NuclearPhysics#ParticlePhysics#NuclearScience#QuantumMechanics
#NuclearEnergy#NuclearFission#NuclearFusion#ParticleAccelerator
#AtomicPhysics#NuclearResearch

Comments

Post a Comment

Popular posts from this blog

Shape-shifting experiment challenges interpretation of how cadmium nuclei move

Image
Atomic nuclei take a range of shapes, from spherical (like a basketball) to deformed (like an American football). Spherical nuclei are often described by the motion of a small fraction of the protons and neutrons, while deformed nuclei tend to rotate as a collective whole. A third kind of motion has been proposed since the 1950s. In this motion, known as nuclear vibration, atomic nuclei fluctuate about an average shape. Scientists recently investigated cadmium-106 using a technique called Coulomb excitation to probe its nuclear shape . They found clear experimental evidence that the vibrational description fails for this isotope's nucleus. This finding is counter to the expected results. Research published in Physics Letters B builds on a long quest to understand the transition between spherical and deformed nuclei . This transition often includes vibrational motion as an intermediate step. The new result suggests that nuclear physicists may need to revise the long-standing para...
Read more

HOMESPACE NEWS Mysterious Physics Revealed: “One of the Most Violent Events You Can Imagine in the Universe”

Image
Recent simulations of two black holes colliding at close to the speed of light have shed light on the enigmatic physics behind what has been called by one astrophysicist as “one of the most violent events you can imagine in the universe.” The findings, published in Physical Review Letters, is the first detailed look at the aftermath of such a cataclysmic clash, and shows how a remnant black hole would form and send gravitational waves through the cosmos. Black hole mergers are one of the few events in the universe energetic enough to produce detectable gravitational waves, which carry energy produced by massive cosmic collisions. Like ripples in a pond, these waves flow through the universe distorting space and time. But unlike waves traveling through water, they are extremely tiny, and propagate through “spacetime,” the mind-bending concept that combines the three dimensions of space with the idea of time. This simulation shows two black holes colliding near the speed of light, revea...
Read more

Nuclear power: The safer and cheaper alternative to fossil fuels

Image
As countries across the globe struggle to balance their desire for a reliable energy supply with their contribution to climate change, nuclear power presents a solution. The global reliance on fossil fuels is a function of our energy needs, and although there have been numerous initiatives implemented in order to reduce demand, such as levying large taxes on air transport, appropriate sources of supply still need to be defined. Fossil fuels such as coal, oil and gas have the benefit of being capable of servicing our energy needs. However, they are a chief contributor to climate change, and as countries attempt to meet the Paris Agreement of keeping global temperature below 2o above pre-industrial levels, non-carbon energy sources are essential. Positives and negatives So, what are the pros and cons of nuclear power as a safer, cheaper alternative to fossil fuels? Well, where renewable sources such as wind or solar are clean, they are also intermittent, require an uneven geographical ...
Read more