Direct evidence revealed for rare pulsing pear-shapes in Gadolinium nuclei
For the first time, scientists have acquired direct evidence of rare, pulsing pear-shaped structures within atomic nuclei of the rare-earth element Gadolinium, thanks to new research led by the University of Surrey, the National Physical Laboratory (NPL) and the IFIN-HH research institute in Bucharest, Romania.

The study, published in Physical Review Letters, provides definitive proof of a strong collective ‘octupole excitation’ in the nucleus of Gadolinium-150, a long-lived radioactive isotope of this rare-earth element, which is used in applications such as superconductors, nuclear power operations and MRI contrast materials.
The experimental signature is interpreted as the protons and neutrons inside the atomic nucleus vibrating in a coordinated pattern, resulting in a pulsing, asymmetric, pear-shaped structure.
Using high-precision gamma-ray measurements of emissions from the nucleus of Gadolinium-150, researchers were able to observe the signature fingerprints of these incredibly tiny pear-shaped structures. Atomic nuclei are so small that even the most advanced optical microscopes are unable to detect them, but information on their structure can be obtained by measuring the characteristic (gamma-ray) emissions as they relax.
The findings open a new window into the quantum world, providing what can be described as a ‘femtoscope’ – a high-precision ‘nuclear microscope’ – that allows scientists to look deep into the subatomic structures that shape our universe.
The results also represent a unique challenge to current theoretical models, which struggle to explain how these shapes can arise from complex interactions of the protons and neutrons which make up the Gadolinium-150 nucleus.
The research involved an international collaboration of 12 institutions from the UK, Romania, India, Japan, China and the Czech Republic.
The National Physical Laboratory is the UK’s National Metrology Institute and is responsible for traceability of all radioactivity measurements in the UK to the SI unit of the becquerel (Bq).
###
Notes to editors
- Dr Esra Yuksel and Professor Patrick Regan are available for interview; please contact mediarelations@surrey.ac.uk
- The full paper is available at https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.092501
Media Contacts
External Communications and PR team
Phone: +44 (0)1483 684380 / 688914 / 684378
Email: mediarelations@surrey.ac.uk
Out of hours: +44 (0)7773 479911