New tech uses isomeric beams to study how and where the galaxy makes one of its most common elements

June 19, 2018, US Department of Energy
The map shows the galactic gamma radiation from aluminum-26 decay as measured by the COMPTEL telescope. Credit: US Department of Energy

Our galaxy produces and destroys the element aluminum-26 in the process of making magnesium-26. As it forms, it can be momentarily "stuck" in a mirror-image (isomeric) state. Getting stuck lets other reactions occur that destroy the element. Measuring how much aluminum-26 the galaxy makes is tough because scientists have to know how much is destroyed. For the first time, scientists produced an aluminum-26 beam in an isomeric state. They used the beam to determine how fast aluminum-26 is destroyed. The resulting study offers the first experimental result for aluminum-26 synthesis.

As a consequence of this new isomeric beam, our understanding of how much aluminum-26 is being formed and destroyed in the galaxy has changed. The impact? We have more realistic data to use in the calculations that attempt to explain the observations made by gamma-ray telescopes. Further, the successful production and use of an isomeric beam can be generalized to other examples. It lets researchers explore the influence of long-lived in the creation of elements by the stars.

Satellites equipped with gamma-ray telescopes have proven to be powerful tools for finding evidence that elements are continually being produced in our galaxy. For example, the detection of a gamma ray associated with the decay of radioactive aluminum-26 would not be possible if aluminum-26 wasn't being continually formed, as it would all have decayed away long ago. However, while this observation indicates that aluminum-26 is continually being formed in the galaxy, it does not tell us where the formation occurs (e.g., novae, supernovae, or giant stars). To understand the observations, experiments in the laboratory must be performed to determine what conditions are most suited to form aluminum-26 in the cosmos. One problem in determining this is the fact that aluminum-26 has an excited state that survives for a few seconds before it decays to the of magnesium-26. Because this state lives so much longer than other excited states, it is classified as isomeric. When aluminum-26 is formed in the galaxy, it is possible that it could be momentarily "stuck" in the isomeric state, allowing time for another reaction to occur that destroys the . To fully understand how much aluminum-26 is being formed in the galaxy, one needs to understand how much of this isotope is destroyed while "stuck" in this long-lived state.

To determine the production and destruction rates of aluminum-26, one must create a beam of aluminum-26 when it is in the ground state and when it is in the long-lived state. While the former has been accomplished at a number of laboratories, the latter was only recently made possible at the ATLAS facility at Argonne National Laboratory. Using this isomeric beam of aluminum-26, researchers determined for the first time the probability that a portion of the aluminum-26 was destroyed before reaching the ground state because the passed through the isomer.

Explore further: Wet aluminum hydroxide and oxyhydroxide particles release hydrogen when irradiated

More information: S. Almaraz-Calderon et al. Study of the Alm26(d,p)Al27 Reaction and the Influence of the Al26 0+ Isomer on the Destruction of Al26 in the Galaxy, Physical Review Letters (2017). DOI: 10.1103/PhysRevLett.119.072701

Related Stories

Examining exploding stars through the atomic nucleus

February 18, 2017

Imagine being able to view microscopic aspects of a classical nova, a massive stellar explosion on the surface of a white dwarf star (about as big as Earth), in a laboratory rather than from afar via a telescope.

Research reveals star forming activity

January 11, 2006

Where do elements, such as iron in our blood or calcium in our bones, come from? Astronomers say they come from thermonuclear reactions in hundreds of millions of stars that burn at high temperatures in our galaxy. Stars ...

Recommended for you

Giant flare detected on a pre-main sequence M star

November 13, 2018

Using the Next Generation Transit Survey (NGTS), astronomers have identified an energetic flare displaying quasi-periodic pulsations on the pre-main sequence M star NGTS J121939.5-355557. The newly detected flare is one of ...

Galaxies like Russian dolls

November 13, 2018

Jairo Méndez Abreu and Adriana de Lorenzo-Cáceres, researchers at the Instituto de Astrofísica de Canarias (IAC), have discovered a peanut-shaped structure in the inner bar of a double-barred galaxy close to the Milky ...

Scientists capture the sound of sunrise on Mars

November 9, 2018

Scientists have created the soundtrack of the 5,000th Mars sunrise captured by the robotic exploration rover, Opportunity, using data sonification techniques to create a two-minute piece of music.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.