Zahlavi

Research Overview

The name of the department originates from time when the department has been involved in traditional beta- and gamma-ray nuclear spectroscopy and applications of related methods. Since these early days research topics of the deparment broadened significantly and currently include modern experimental nuclear physics as well as radiochemical activation analyses.

Collaboration with prestigious laboratories abroad (CERN, BNL, GSI) in the field of exploration properties of nuclear matter under extreme conditions plays one of the key roles in research of the department. The Ultra-Relativistic Heavy Ion Group focuses primarily on study of quark-gluon plasma (QGP). This new phase of nuclear matter which exhibits behavior close to that of perfect liquid, can be created in laboratory in collisions of heavy nuclei at ultra-relativistic energies accessible only at the world largest accelerators - LHC (Large Hadron Collider) in the European laboratory CERN and RHIC (Relativistic Heavy Ion Collider) at Brookhaven National Laboratory (BNL) in the U.S.A.. The ALICE experiment at CERN and the STAR experiment at BNL, in which members of the group participate since very beginning, study nuclear collisions in the energy domain of tens of GeV to TeV. This research is related for example to models of early evolution of the Universe after Big Bang and search for critical point of the phase diagram of nuclear matter.

Research activities of the Relativistic Heavy Ion Group are devoted to investigation of nuclear collisions in the energy domain of units of GeV available at GSI Darmstadt (Germany) and focus on exploration of properties of hadrons in nuclear matter at high baryon density. In particular the group is for many years involved in the large international experiment HADES at the SIS18 accelerator. In parallel are the group members actively involved in preparation of a new experiment CBM at the FAIR facility at GSI that will allow to explore nuclear matter at high baryon density with unprecedented precision. Exploration of the phase diagram of nuclear matter in this domain further extends measurements carried out at RHIC and can be linked to models of neutron stars or understanding supernova explosions.

An inherent part of research carried within large international experiments is research in the Electron Spectroscopy Group. This group belongs to founding members of the international experiment KATRIN (KIT Karlsruhe, Germany) designed to measure neutrino mass with sensitivity of 0.2 eV, ten times better than so far experimentally achieved. This unique experimental device became operational in 2018. The Czech team from NPI is primarily responsible for development of ultra-stable method to control energy scale stability of the KATRIN spectrometer together with development of a gaseous 83mKr generator.

The members of the department are also traditionally involved in international experiments located at the radioactive ion beam facility ISOLDE at CERN. Currently we are participating in a new project VITO that will make use of laser polarized isotope beams and the WISARD experiment, successor of the project WITCH, that will search for a possible presence of scalar current in weak interaction in electron-neutrino correlations.

The gamma-ray spectrometry as one of the traditional nuclear spectroscopic methods is employed by the Activation Analysis Group. The group is involved in development and applications of advanced methods of neutron and photon activation analyses that serve to determine occurrence of a large variety of chemical elements, especially elements present only in trace and ultra-trace amounts, in diverse types of materials. These methods can be applied in geo- and astrochemistry, materials engineering, agriculture, food technology, archeological research, environmental studies and protection of cultural heritage. High sensitivity of activation methods, especially in combination with radiochemical separation, is beneficial in analysis of small and rare samples e.g. from meteorites, fine art masterpieces or as in our recent study, from the remains of the astronomer Tycho Brahe to verify whether he was poisoned by mercury. Another tool employed in the group for analysis of elements is the X-ray fluorescence suitable especially for non-destructive determination of composition of metalic archeological artifacts.