Liverpool physicists join world’s premier nuclear physics facility


A model of the FAIR facility, currently under construction in Germany

University of Liverpool physicists are to take part in the most advanced international nuclear physics facility in the world which will study extremely exotic nuclei and nuclear matter.

The Science and Technology Facilities Council (STFC) has signed an agreement to make the UK an associate member of FAIR (Facility for Antiproton and Ion Research), a £1.35 billion international project.

The FAIR facility which is currently under construction in Darmstadt, Germany will provide new opportunities to study extremely exotic nuclei and nuclear matter which will contribute to fundamental physics, as well as having an enormous impact on astrophysics; from the evolution of the early universe to the structure of neutron stars.

It will house several main experiments including R3B (Reactions with Relativistic Radioactive Beams) which is being built by a large international collaboration and for which the University’s Semiconductor Detector Centre is in the process of constructing the Silicon Tracker.


A computer aided design (CAD) drawing of the R3B silicon tracker being constructed by the University’s Department of Physics

The R3B experiment will exploit the FAIR radioactive ion beams of high intensity and purity which will be available with energies up to 1 to 2 GeV per nucleon, the highest energies worldwide for such ion beams.

The R3B Silicon Tracker, fully funded by STFC and currently in its design and prototyping phase, consists of three layers of double-sided Silicon microstrip sensors, with 100 micron thickness for the inner layer and 300 micron thickness for the two outer layers.  It is a key component of the R3B experiment, surrounding a liquid hydrogen target. It will provide vertexing and tracking of the high momentum particles created in the interaction of the radioactive ion beam with this target.

”Being part of the FAIR project is a great opportunity and will strongly benefit the international R3B collaboration which the University’s Physics department is a major contributor to”

Dr Marielle Chartier, from the Department of Physics who is leading the project at the University of Liverpool, said: “Being part of the FAIR project is a great opportunity to demonstrate the UK’s world leading expertise in nuclear physics and will strongly benefit the international R3B collaboration which the University’s Physics department is a major contributor to.

“Future experiments will help us to understand the nature of nucleon-nucleon correlations beyond the mean-field level in isospin asymmetric nuclei and nuclear matter which is a fundamental issue in nuclear physics today.

“The modification of these correlations as a function of the density, temperature and isospin asymmetry of the nuclear medium will determine the nature of many-body systems as diverse as finite atomic nuclei, extended nuclear matter and compact astrophysical objects such as neutron stars.

“Theoretically, it remains a very challenging problem to incorporate such correlations in the nuclear many-body system starting from the bare nucleon-nucleon interaction and experimental studies are therefore very important.”


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