Moscovium and the Heaviest Elements: Dubna, Livermore and the Hot Fusion Breakthrough

Overview

The podcast chronicles the ongoing quest to push the periodic table to its heaviest, shortest-lived elements, highlighting Moscovium and the teams that discovered and studied it. It explains the hot fusion approach that uses neutron-rich beams to stabilize superheavy nuclei and details the collaboration between Dubna in Russia and Lawrence Livermore National Laboratory in the United States.

Key insights

• Moscovium (element 115) was produced using a calcium-48 beam directed at americium targets, a method that helped overcome the Coulomb barrier in superheavy element formation.
• Calcium-48 is neutron-rich, costly, and energy-intensive to produce, yet it enabled the creation of the elements 114, 116, and ultimately gave access to heavier isotopes through decay chains.
• Only about 100 atoms of moscovium have been observed, with isotopes such as MC289 and MC290 displaying extremely short half-lives, underscoring the rarity of these discoveries.
• The podcast also discusses the naming of Moscovium after the Moscow region and Livermorium after the city of Livermore, connecting scientific achievement with regional heritage.

Context and the race for the heaviest elements

The podcast examines the unprecedented challenge of creating and studying the heaviest chemical elements, tracing the historical rivalry between Dubna's Joint Institute for Nuclear Research and Berkeley Lab in the United States. It explains how early 21st century collaborations, particularly between Dubna and Lawrence Livermore National Laboratory, aimed to complete the eighth row of the periodic table by producing elements heavier than oganesson. The broader scientific goal is to understand the limits of nuclear stability and the properties of superheavy elements that exist for only milliseconds.

Hot fusion and the calcium-48 beam

The core production method discussed is hot fusion. In this process, a beam of ions is fired at a target nucleus to create a heavier element through fusion if overcome the electrostatic repulsion. The podcast highlights a key innovation: using a calcium-48 beam, a neutron-rich isotope with eight extra neutrons compared with the most abundant calcium. This approach helps discard excess neutrons as ballast, allowing the resulting nucleus to stabilize long enough for detection. Calcium-48 is exceptionally precious and expensive, and the accelerator consumes approximately 0.5 milligrams per hour during operation. This beam was instrumental in the discoveries of elements 114 and 116, and adjusting the target allowed researchers to reach element 118.

Production routes to Moscovium

There are two documented pathways to moscovium. The direct collision route involves bombarding americium with calcium, yielding isotopes with half-lives around 100 milliseconds. A second route uses decay chains from heavier, previously discovered elements. In particular, alpha decay from element 117 (tennessine) can transmute into moscovium. The collaboration produced MC289 and MC290 through these chains, but even these isotopes decay in less than a second. Across the campaigns, roughly a hundred atoms of moscovium have been observed, making it one of the rarest elements recorded in the laboratory setting.

The naming and the next stop on the table

In the podcast, the Dubna-Livermore team also discusses the naming of new elements. Moscovium is named after the Moscow region, while livermorium is named for the city of Livermore, reflecting local heritage. The episode previews the next segment, where Kit Chapman speaks with Livermore’s mayor John Marchand about the naming ceremony and the significance of the element to the city. The episode ends with encouragement to explore Chemistry World’s special collection celebrating Mendeleev’s birthday and to engage with the Chemistry in Its Element podcast series.

Relation to broader science and accessibility

Beyond the specifics of Moscovium, the podcast highlights how the creation of superheavy elements informs fundamental chemistry and nuclear physics. It also underscores the role of international collaboration in pushing scientific boundaries and the public-facing importance of linking discoveries to regional and national identities. The described research exemplifies the broader mission of trusted STEM content and the value of curation and context in science communication.