Yorkshire Philosophical Society

Event Information

Exotic isotopes – what can we learn from them?

Prof. Andrei Andreyev, Anniversary Professor of Physics, University of York

There are 86 stable elements on Earth, with 284 stable isotopes between them, spanning the range between hydrogen and uranium. However, it is predicted that in theory approximately 6000 unstable (radioactive) isotopes could also exist, albeit most of them only for a very short period of time.  Because of this, all these so called exotic isotopes have to be man-made. In this lecture nuclear physicist Professor Andrei Andreyev from the University of York will explain how such isotopes can be produced in a laboratory, e.g. by combining state-of-the art particle accelerators, the unique selectivity of laser-based atomic techniques and powerful multi-detector systems, being developed by large international collaborations.  Following examples of a purely fundamental interest in such isotopes, Professor Andreyev will show how understanding of their unique properties helps fellow scientists to develop  safer methods of producing nuclear energy and advanced cancer treatments.

Report

This was a wide ranging talk with superb overheads, considerable detail and humour, that elicited many questions. There are now about 2700 man-made radio-isotopes, made in nuclear reactors; in nuclear explosions; and more cleanly in particle accelerators such as the Large Hadron Collider.

Fundamental research on the shapes of atomic nuclei shows that prolate, like a rugby ball, is most common, but others include oblate and pear-shaped. Applications include radiopharmaceuticals, which have a radioactive isotope with a limited half-life (eg 8 hours for 210At) to kill the cancer cells, combined with a carrier molecule to deliver it to a specific area.

Radioactive dating of organic remains, such as Ötzi the Iceman, relies on cosmic rays interacting with atmospheric nitrogen to make 14C which then decays slowly. Many of the world’s nuclear power stations are being shut down, and the future may lie with using thorium instead of uranium isotopes.

Rod Leonard