A new method detects residual contaminants in ultra-pure helium gas, critical to nuclear physics experiments

The gas that makes balloons float is also vital to scientific experiments. In these experiments, natural helium (He) is purified, but it contains a tiny bit of a slightly different form of helium, known as the isotope ³He. A sample can contain just one ³He in every million helium atoms. That’s too much for many experiments. Many experiments require ultra-pure helium, with a ³He component at least another million times smaller, or one in a trillion of the He atoms. Although techniques are believed to produce ultra-pure helium, until recently no experimental methods have confirmed that the amount of ³He present in a sample is indeed that small. Now, scientists at the ATLAS facility at Argonne National Laboratory have used accelerator mass spectrometry (AMS) to precisely measure the very small concentrations of ³He present. Read more.

Finding may help researchers fine-tune metal-oxide catalysts to enhance energy storage technology

Chemical reactions that release oxygen in the presence of a catalyst, known as oxygen-evolution reactions, are a crucial part of chemical energy storage processes, including water splitting, electrochemical carbon dioxide reduction, and ammonia production. The kinetics of this type of reaction are generally slow, but compounds called metal oxides can have catalytic activities that vary over several orders of magnitude, with some exhibiting the highest such rates reported to date. The physical origins of these observed catalytic activities is not well-understood.

Now, a team at MIT has shown that in some of these catalysts oxygen doesn’t come only from the water molecules surrounding the catalyst material; some of it comes from within the crystal lattice of the catalyst material itself. Read more.

The first well-characterized materials containing berkelium differ from expectations

Berkelium is one of the few elements that has yet to be characterized in detail, largely because the only available isotope, ²⁴⁹Bk, has a half-life of only 320 days. Using single crystal x-ray diffraction, researchers at Florida State University structurally characterized a complex containing the actinide-group element berkelium. The characterization reveals unexpected findings, such as a lack of structural similarities between berkelium and its lanthanide analog terbium. Read more.

As major research reactors supplying Mo-99 are aging and ceasing production, an alternative method offers a simplified way to diversify production and help ensure continued Mo-99 supplies for uninterrupted nuclear medicine services. Read more.