University of the Western Cape student a part in UWC’s International Research Collaboration in Neutrino Physics

These tiny, nearly massless, fast-moving particles produced in nuclear fusion processes that power the sun and stars can solve challenges with fundamental physics questions. The research also increases local expertise about radon – a substance which poses a health hazard in the gold mining industry.

UWC Physics student, Goitse Ramonnye, is graduating in absentia on 20 April after being employed in the Netherlands with an organisation called the Nuclear Research and Consultancy Group (NRG). Her Master’s work is linked to nEXO, which is an experiment to look for very rare nuclear decays that involve neutrinos.

Ramonnye is the first student at UWC to graduate as part of this collaboration. Her work was done at UWC and was aimed at measuring radon gas, one of the naturally occurring background radioactive materials that interfere with neutrino measurements.

According to Professor Robbie Lindsay from the Department of Physics and Astronomy, UWC’s expertise in radon is useful in this work. Ramonnye’s thesis tested how well our existing apparatus could measure this and indicated where we need to get better equipment.

Ramonnye is the first UWC graduate linked to nEXO – a large international collaboration that the UWC Physics Department has joined. It is a $250m project searching for an exotic nuclear decay which will change physics if discovered.

The nEXO experiment will measure rare decays in 4000 kg of liquid Xenon in SNOLAB, a 2km underground science laboratory specialising in neutrino and dark matter physics, and is linked to a nickel mine in Canada.

Several UWC students are working on the nEXO project and have done research at some of the top universities and institutes in the world. These include Stanford University and SNOLAB.

Professor Lindsay said Ramonnye’s research will provide a better understanding and more accurate measurement of radon. Her work, led by Prof Lindsay and Prof Smarajit Triambak, the South African Research Chair in Nuclear Physics at UWC, also includes radon measurements in Steenkampskraal – a mine that is being redeveloped close to Vanrhynsdorp.

Ramonnye, a 27-year-old from Luka, a small village in Rustenburg within the North West province, said from the Netherlands that the opportunity of being part of an international research exchange means a lot to her.

“Collaborating or working internationally is a way of life for me. I live for research. I’m very happy that my research will add to the body of knowledge and contribute to advancement in this field,” she said.

“The strength of this study comes from the entire nEXO project. I am glad that I can contribute to more world class fundamental physics research and development.”

More About Neutrinos
Neutrinos come from violent astrophysical events like exploding stars and gamma ray bursts, are abundant in the universe, and can move as easily through lead as we move through air. Neutrinos belong to the family of particles called leptons, which are subject to the weak force that underlies certain processes of radioactive decay.

Important breakthroughs in physics do not happen often, but when they occur, they profoundly influence civilisation.
Neutrinos explained
Science tells us that on a small scale, everything is made up of atoms which consist of protons, neutrons and electrons. But neutrons and protons are not elementary, and a neutron outside an atom can decay into a proton and an electron.

When this decay was studied, the next mystery appeared: energy seemed to get lost in this process. A prediction which eventually proved to be correct, was that another particle is created in this process. That particle is the neutrino which hardly interacts with anything and is notoriously hard to study.

Neutrinos are very light particles created in huge numbers in the reactions taking place in the sun. However, measurements on earth did not detect as many neutrinos as predicted. After many careful experiments, physicists realised that neutrinos come in three different types, and that they can change from one “flavour” to another.

This mystery about the nature of neutrinos has now led to several major collaborations worldwide aimed at understanding if and where the “standard model” of physics is going wrong.

The experimentalists are going to extraordinary lengths to solve this mystery: The ICECUBE experiment in Antarctica is measuring neutrinos coming from outer space in a cubic kilometre with hundreds of detectors. nEXO will use tons of liquid Xenon in a large underground laboratory.