Welcome to the website of the CBM experiment at FAIR


Exploring Cosmic Matter in the Laboratory

The Compressed Baryonic Matter (CBM) experiment will be one of the major scientific pillars of the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. The goal of the CBM research program is to explore the properties of nuclear matter at high densities using high-energy nucleus-nucleus collisions. This includes the study of the equation-of-state, which governs the structure of neutron stars, and the dynamics of supernova explosions and of neutron star mergers. A fundamental aspect of the CBM program is the search for a predicted phase transition at high densities, where the nucleons are expected to dissolve into their elementary constituents, and chiral symmetry is restored.

The CBM detector is designed to measure the collective behaviour of hadrons, together with rare diagnostic probes such as multi-strange hyperons, charmed particles and lepton pairs with unprecedented precision and statistics. Most of these particles will be studied for the first time in the FAIR energy range. In order to achieve the required precision, the measurements will be performed at reaction rates up to 10 MHz. This requires very fast and radiation hard detectors, a novel data read-out and analysis concept including free streaming front-end electronics, and a high performance computing cluster for online event selection. The CBM prototype detectors, the data read-out chain and the event reconstruction algorithms are under commissioning in the miniCBM experiment with heavy-ion beams at GSI-SIS18, and partly used in other experiments like HADES at GSI and STAR at RHIC-BNL during the FAIR phase 0.

The CBM experiment is realized by an international collaboration of 470 scientists from 56 institutions and 12 countries. The last face-to-face collaboration meeting took place in Kolkata (India) from Sept. 29 - Oct.3, 2019.


Progress in construction of the CBM cave

Recent photo of the CBM cave comprising four levels, seen from the beam entrance. The beam dump consisting of 4000 tons of steel and 5000 tons of concrete (see sketch below) is already installed.
CBMcave picture
Sketch of the CBM cave with the underground hall containing the detectors systems HADES and CBM, and three upper floors hosting supply systems, electronics, and counting rooms.  

CBM collaboration supported by the EU project CREMLINplus with 5.8 million euros for joint activities with NICA

Within the new EU project CREMLINplus (Connecting Russian and European Measures for Large-scale Research Infrastructures - plus), the European Commission is providing 25 million euros for scientific cooperation between European research infrastructures - in particular the projects of the European Strategy Forum for Research Infrastructures (ESFRI) and the mega science projects in Russia. Based on the long-term cooperation of GSI with the Joint Institute for Nuclear Research (JINR) in Dubna in the large-scale projects of FAIR (Facility for Antiproton and Ion Research) and NICA (Nuclotron-based Ion Collider facility), projects beneficial both for the CBM experiment and for the NICA experiments are funded with 4.6 million euros. These activities include the joint development of silicon track detectors, the design of ultra-fast, self-triggered data acquisition systems, the development of software packages for online event selection and data analysis, as well as the construction of target chambers, extremely thin beam pipes and calorimeters for event characterization. CBM groups also participate in another work package of CREMLINplus, which is devoted to the development of the next generation of ultra-thin silicon pixel sensors (MAPS - Monolithic Active Pixel Sensors, and is funded by 1.2 million euro. The CREMLINplus project started in February 2020, and supports over a period of four years twelve institutes of the CBM collaboration from seven countries.

In addition to the cooperation between CBM and NICA, CREMLINplus also supports the cooperation of European research infrastructures in the field of neutron research, research with synchrotron beams and lasers, as well as in particle physics with the respective Russian megascience projects (PIK, USSR, EXCELS and SCT).

CREMLINplus kick-off workshop on February 19-20, 2020, at DESY, Hamburg

Million Euro agreement for research signed between GSI and JINR

road Map
Signature ceremony of the cooperation agreement between JINR and GSI

Intensifying research cooperation, strengthening cutting-edge research and promoting young researchers – these are some of the key goals of the "German-Russian Roadmap for Cooperation in Education, Science, Research and Innovation", which Germany and Russia agreed in December 2018. An important step in this context was the signing of an agreement between the GSI Helmholtzzentrum für Schwerionenforschung and the Joint Institute for Nuclear Research (JINR).

The main goal of the German-Russian Roadmap is to expand cooperation at major research infrastructures in Russia. One of the projects is the instrumentation and scientific usage of the future accelerator complex NICA (Nuclotron-based Ion Collider fAcility), currently being built in Dubna at JINR. The German contributions to this cooperation are financed by the Federal Ministry of Education and Research (BMBF) and handled by GSI. For this purpose, a cooperation agreement between JINR and GSI has been worked out, which has a total volume of about 20 million Euros. It was signed in early February in Moscow during the "Helmholtz Winter Talks 2020", a traditional event for the exchange of views between decision-makers from politics, science and society in Russia and Germany.

The agreement on technical cooperation between GSI and JINR consists of several subprojects: coordination and technical follow-up, stochastic cooling for the NICA collider, silicon tracking system for the NICA experiment BM@N as well as read-out electronics and data acquisition for this experiment, research and development for the superconducting high intensity ion injector Linacs@JINR and finally beam diagnostics and LLRF electronics for linear accelerators.

Detailed working packages have been proposed in an application, which is under evaluation by the BMBF. A substantial part of the funding is requested for the construction of the Silicon tracking system, its read out-electronics, and the data acquisition system. These subprojects have a large synergy potential both for the BM@N experiment at NICA, and for the CBM experiment at FAIR.