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 ( construction site April 2021 )

Russian-German Roadmap project started

The 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.

STS_BNN BM@N/NICA: Silicon Tracking System with 4 stations comprising 300 double-sided micro-strip sensors

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

After signature of the cooperation agreement between JINR and GSI in 2020, detailed working packages have been approved by the BMBF in early 2021. The total volume of the subprojects is 21.3 million Euros, with 14.3 million Euros devoted to the realization of the NICA experiments BM@N and MPD, i.e. to the construction of the Silicon tracking system, its read out-electronics, and the data acquisition system.

CBM/FAIR: Silicon Tracking System with 8 stations comprising 900 double-sided micro-strip sensors STS_CBM

These subprojects have a large synergy potential both for the BM@N experiment at NICA, and for the CBM experiment at FAIR. About 9.6 million Euros are assigned to the purchase of hardware, while 4.7 million Euros are foreseen to hire personnel for the development and construction tasks. For the present, the project is scheduled for five years. The opening of the positions will be announced at the GSI website and at the CBM website

Another component of the Russian-German Roadmap are stipends for Russian students and postdocs, who want to work at GSI for 1 – 9 months. The stipends can be applied via daad.de