Within the Low-Energy activity, there is research within nuclear physics by the two experiments ISOLDE and AEgIS at CERN. A major motivation for studying the atomic nucleus is to gain a fundamental understanding of our world, including its origin and future, as well as its current state. Nuclear physics has as its objective the investigation and understanding of nuclei: the hearts of atoms and the place where almost all mass of visible matter resides. Nuclear physics can explain how stars continually work to release virtually all of the useful energy in the world, while at the same time assembling the various elements. Thus today there is a strong collaboration between nuclear physics and astrophysics.

ISOLDE  is an interdisciplinary facility covering nuclear structure,  nuclear chemistry,  astrophysics, atomic physics, solid-state physics, and medical physics, with more than 1300 users from 43 countries. ISOLDE has been the leading facility globally to produce isotope-separated short-lived radioactive ions for several decades. It is today the world’s premier facility to produce re-accelerated radioactive ion beams (RIB), providing more than 1300 different isotopes from 73 chemical elements. Norway has a rich history within the ISOLDE collaboration in nuclear physics and nuclear chemistry.  In recent years,  the  Nuclear  Physics group in  Oslo has had a very high success rate in proposing experiments. The group has led four individual ISOLDE experiments with either Andreas Görgen or Sunniva Siem being the spokesperson for the collaboration.  The  Oslo group is planning to pursue both physics cases,  related to nuclear shapes and neutron capture rates,  with further proposals in the future, including a  campaign of experiments with  OSCAR  at  ISOLDE.  Furthermore, the collaboration has ambitious plans to upgrade the experimental facility,  for example, by constructing a  storage ring for  RIB.

The "Miniball" detector receiving beams from the Radioactive Beam Experiment (REX) and the Isotope-Separator On-Line (ISOLDE) facilities. (Image: CERN)

AEgIS is one of the few international collaborations based at the CERN flagship Antiproton Decelerator (AD), the only facility where cold antiprotons are available. In 2021, the AD will start feeding the Extremely Low Energy Antiproton facility which will provide the antimatter experiments with antiprotons of only  100  keV kinetic energy.  This will be a  considerable boost to the number of antiprotons that can be used for physics experiments. After having validated the charge exchange reaction as a  mechanism for pulsed antihydrogen formation in  2018,  AEgIS is entering  Phase  2  which consists in an upgrade of the antihydrogen production trap to increase the efficiency and the directionality of the antihydrogen production. Several technological developments will be deployed that will put  AEgIS in a  competitive position for measuring the effect of the Earth’s gravitational field on antihydrogen. Norway has been actively involved in AEgIS since its beginning more than 10 years ago through several master, PhD and postdoctoral students based in the UiB and UiO groups.

There are many potential applications of nuclear physics, e.g. in energy production, medical diagnosis and treatments. There are still several challenges, which make nuclear physics an exciting and active field of future research. Some of the experiments cover topics such as nuclear shapes, shape coexistence, and highly excited nuclei's statistical properties.

Leader: Sunniva Siem
Deputy: Andreas Görgen