The CALIFA detector is ready to operate in Germany after 20 years of work

The Spanish team on the project with Dolores Cortina (IFIC) on the left
The Spanish team on the project with Dolores Cortina (IFIC) on the left
The Institute of Corpuscular Physics (IFIC, UV-CSIC) is part of the team that has travelled to the city of Darmstadt to install the last modules of the CALIFA detector, a calorimeter that will be installed in R3B, one of the scientific collaborations in nuclear physics from the new international research centre FAIR. This milestone represents the culmination of almost 20 years of work in the design and subsequent construction of the detector, in a project led by the Galician Institute of High Energy Physics (IGFAE, USC).

Researchers from the Institute of Corpuscular Physics (IFIC, CSIC-UV), the Institute of Structure of Matter (IEM, CSIC), the Galician Institute of High Energy Physics (IGFAE, USC) and the University of Vigo have travelled these days to the city of Darmstadt to install these latest detection modules designed and built in Spain. CALIFA will be installed in the R3B experiment, which currently has the participation of more than 250 scientists from 15 countries, is dedicated to the study of the structure and dynamics of the atomic nucleus and has been coordinated since May 2017 by IFIC researcher Dolores Curtain. The project has also involved several Galician companies specialised in carbon fibre manufacturing, precision machining and metrology.

In this last phase, the Spanish team has completed the construction and assembly of the CALIFA detection modules known as CEPA. This step will substantially improve the detection of gamma radiation and high-energy charged particles that are produced at the time of the nuclear reaction. This will significantly increase the efficiency of the R3B experiment, and will facilitate the performance of precision measurements making the most of the advantages of the accelerated ion beams in FAIR.

With the delivery of CEPA, a construction phase of CALIFA that has lasted more than 10 years closes, in which personnel from Spain, Germany and Sweden have participated. The current cost of the detector exceeds 3.8 million euros. Once the work is completed, CALIFA’s final cost will exceed 5 million.

The CALIFA calorimeter is capable of simultaneously detecting charged particles and gamma radiation, covering an unprecedented energy range, from kiloelectronvolts (KeV) to hundreds of megaelectronvolts (MeV). The detection technology used in this type of detectors, as well as the techniques for reconstructing the information collected, are similar to those developed in the field of medical imaging. In fact, the R&D carried out for CALIFA has given rise to a "proof of concept" project whose purpose is to accelerate the transfer of knowledge and results generated in the field of fundamental research.

About R3B and FAIR

The R3B experiment (Reactions with Relativistic Radioactive Beams) uses radioactive ions at speeds close to light, with which an extensive research program is developed on crucial questions for nuclear physics. Among them, the study of fundamental properties of atomic nuclei and the force responsible for uniting the protons and neutrons that form them, as well as the importance of the correlations that occur between nucleons, stand out. Thus, R3B also aims to reproduce the reactions that take place in stars and that are responsible for generating their energy and creating the elements that we see in the Universe.

R3B is one of the experiments being developed at FAIR (Facility for Antiproton and Ion Research in Europe), a new international research centre for the study of the structure and properties of the visible matter that forms the Universe. It is currently under construction and is located near Darmstadt. Once the work is completed, FAIR will be equipped with the most powerful antiproton and heavy ion accelerators in the world. The centre will host more than 3,000 people from 50 countries, who will carry out basic and applied research work in the field of nuclear physics. Its construction, whose cost is around 1.5 billion euros, is funded by a consortium of nine countries.