Something to peak your interest

Nuclei, consisting of protons and neutrons, can be a variety of shapes. So, how do we know what shape the nucleus of an element is? We figure this out by firing a beam of particles (e.g. protons) at a target made up of that element. The beam-target interaction causes the protons and neutrons in the target to vibrate. The shape of the spectrum provides information about the shape of the nucleus. A single peak indicates a spherical nucleus, whereas a double peak indicates either a rugby-ball- or a Smartie-shaped nucleus – that is, a deformed nucleus.

We studied neodymium and samarium (in particular 150Nd and 152Sm) and obtained, contrary to common knowledge, only one wide peak as opposed to the expected two peaks.

What does this mean and why do we care?

These nuclei may not be as deformed as we thought. Their properties are, however used in calculations applicable to nuclear reactor design so accurate, up-to-date information is crucial. These results were published in Physics Letters B: L M Donaldson et al., Phys. Lett. B 776 (2018) 133-138.