US Scientists Forge New Path to Heaviest Element Ever

In a landmark achievement, scientists at the Lawrence Berkeley National Laboratory have successfully created livermorium, one of the heaviest elements on Earth, using a novel technique that could pave the way to even heavier discoveries.

This marks the first time a titanium beam has been successfully used to synthesise a superheavy element. The process involves heating a sample of the rare titanium-50 isotope to nearly 1,650°C (3,000°F) to release ions that are then beamed at another element. This method has yielded a breakthrough in the quest to create heavier elements than ever before, ultimately aiming for the creation of unbinilium, an element with 120 protons.

Livermorium, first synthesised in 2000, holds 116 protons and is not the heaviest element created by humans (that title belongs to oganesson with 118 protons). However, its creation through the fusion of a titanium beam with plutonium serves as a crucial test run for the larger goal of producing unbinilium, the heaviest element ever.

"This reaction had never been demonstrated before, and it was essential to prove it was possible before embarking on our attempt to make 120," explained nuclear chemist Jacklyn Gates, lead researcher at Berkeley Lab.

The traditional method for creating superheavy elements relies on calcium-48, a highly stable isotope with a "magic number" of protons and neutrons. However, titanium-50, while not "magic," possesses the 22 protons needed to reach those heavier atomic weights without disintegrating.

"It was an important first step to try to make something a little bit easier than a new element to see how going from a calcium beam to a titanium beam changes the rate at which we produce these elements," explained physicist Jennifer Pore from Berkeley Lab.

The team's successful creation of livermorium, despite requiring 22 days of operation at Berkeley Lab's 88-inch cyclotron and yielding only two atoms, provides confidence in the method's efficacy for producing unbinilium.

The new approach promises a significantly faster route to creating unbinilium than previous methods. However, the process still remains a lengthy and complex undertaking. "We think it will take about 10 times longer to make 120 than 116," notes Berkeley Lab nuclear physicist Reiner Kruecken.

This breakthrough marks a resurgence in the superheavy element race for Berkeley Lab, a renowned institution that has played a pivotal role in elemental discovery throughout the 20th century.

A global race to synthesise unbinilium has been underway since at least 2006, with attempts by a Russian team at the Joint Institute for Nuclear Research and a German team at the GSI Helmholtz Centre for Heavy Ion Research between 2007 and 2012.

Now, with research teams from the US, China, and Russia vying for the coveted discovery, the potential applications of unbinilium remain an intriguing topic of discussion.

"It's really important that the US is back in this race, because superheavy elements are very important scientifically," said nuclear physicist Witold Nazarewicz, who was not involved in the research, highlighting the scientific significance of exploring these extreme elements.

The creation of unbinilium is anticipated to occur near the theoretical "island of stability," a region where superheavy elements with "magic numbers" of protons and neutrons are predicted to exhibit exceptionally long half-lives. This discovery offers a unique opportunity to explore the extreme limits of atomic behaviour, test existing nuclear physics models, and map the boundaries of atomic nuclei.

The research has been submitted to Physical Review Letters and is available as a preprint on arXiv.