Fundamental Physics Research

In the last decades, several ISOL (Isotope Separation On-Line) facilities have been built around the world with the initial goal to advance fundamental knowledge of the atomic nucleus. Due to the success of these facilities, demand for radioactive ion beams exceeds what most facilities can offer. Unfortunately, many facilities have had to limit the number of experiments or beam times available to scientists.

The goal of the ISOL laboratory within MYRRHA’s Proton Target Facility (PTF) is to focus on experiments that require long periods of uninterrupted radioactive ion beams – a difficult, if not impossible act to perform in existing facilities. These experiments need sufficient time in order to reach the required accuracy for their specific scientific goals.

The PTF will be designed to simultaneously produce radioisotopes for medical applications and isotopes needed for fundamental physics research.



One type of experiment that could be performed in the PTF looks in extremely high detail to radiation emitted during nuclear beta-decay, a process unstable atoms use to become more stable. These experiments hunt to further explain weak interaction, one of the four fundamental forces in nature that is responsible for nuclear beta-decay.

Nature consists of four fundamental forces: gravity, weak interaction, electromagnetic interaction and strong interaction. Of these, we experience gravity (keeping us with our feet on the ground) and electromagnetic interaction (light, electricity, magnetism, etc.) on a daily basis. Strong and weak interaction are more difficult to observe, as they are active in the atomic nucleus. These four fundamental forces are incorporated into the Standard Model theory, which is known to be incomplete. For instance, it does not explain dark energy or the dominance of matter over anti-matter in our universe. So scientists worldwide are trying to search for experimental evidence to further complement this theory. Powerful accelerators play a significant role in creating this evidence, since new 

phenomena can be generated at extremely high energy levels. Alternatively, reviewing “known” phenomena in extremely high detail may reveal small discrepancies with respect to the Standard Model.


Another type of experiment can look in great detail to neutrons (that form the atomic nucleus together with protons) that are emitted from short lived beta-decaying radioisotopes. These so-called “beta-delayed neutrons” are important in several domains. On a fundamental level, they are significant in the formation of new elements in stellar explosions or supernovae. On a more applied level, they are crucial in nuclear reactor control. The properties of these neutrons (their energy, emission pattern and probability to emerge) are extremely sensitive to the underlying atomic nucleus’ structure. Such measurements can assist theoretical models describing the nucleus as a complex multi particle quantum mechanical system.

Also, condensed matter physics (which looks into the microscopic properties of matter) can benefit from radioisotopes. In such experiments, a radioisotope is implanted in a certain type of material. Its radioactive nucleus will then have a specific interaction with the surrounding environment. When the radiation emitted by this radioisotope is measured (this can be gamma rays or electrons), it will reveal information on the properties of the environment in which it was implanted. As such, detailed material properties can be probed with high sensitivity levels. Materials that can be investigated, may include superconductors and new semiconductor materials.