Zahlavi

About Department of Nuclear Reactions

Fundamental Research in a Direction of Nuclear Astrophysics and Exotic Nuclei

The nuclear astrophysics program has started at the late 90' and collaboration was first established with Texas A&M University and INFN LNS Catania. The program is based on indirect techniques and the aim is to study nuclear reactions with astrophysical importance from a stellar burning in CNO cycle to nuclear reactions in AGB stars and Big Bang nucleosynthesis questions. The experiments are partially conducted on U120M cyclotron located in NPI CAS Řež. There are two indirect methods that are utilized - Asymptotic Coefficients method (ANC) and Trojan Horse Method (THM). These methods allow to deduce an astrophysical S-factor or to probe energetic dependence of astrophysical S-factor and determine the properties of low lying resonances in the Gamow region even to the threshold and subthrershold region. Lately, a  collaboration with SPIRAL2/Ganil have been upgraded in the frame of astrophysical problems to a new level of European Associated Laboratory and we participate on construction of the new radioactive beam's facility SPIRAL2 that is opening new possibilities in the research. The activities concerning exotic nuclei aim to study the behavior of nuclear matter in extreme isospin conditions. The phenomenae as nuclear halo, breaking magic numbers, sudden onset of deformation and shape coexistence are under study in a collaboration with physics groups in Ganil, IFIN-HH Magurele, JINR Dubna and other.

Fundamental and Applied Research with Fast Neutron Generators and Activation with Charged Particles

Three fast neutron generators were built in the NPI ASCR by scientific and technical staff of DNR. The generators are powered by the proton beam of U120M cyclotron (in the energy range 20-38 MeV) . Different source reactions allow to generate continuous (p+Be, p+D2O) or quasi-monoenergetic (p+Li) neutron spectra with fluxes up to 1011 n/cm2/s and 109 n/cm2/s, respectively. There are several research programs running within international collaborations: in particular the integral and differential benchmark tests for the validation of neutron cross-sections data library for future fussion power technologies ITER and IFMIF, and the  neutron hardness tests of read-out electronics for ATLAS/CERN calorimeter (MPI München).

The proton and deuteron induced reactions are of great interest for the assessment of induced radioactivity of accelerator components. The cross sections for deuteron (11-20 MeV) and proton (11-37 MeV) induced reactions are measured by stacked-foil technique. There are several international collaborations in this field, we also participate in the NFS collaboration (Neutrons for Science)/SPIRAL2 facility with construction of the automated system for irradiation/measuring of proton/deuteron cross-section - one of the first-day experiments and to be started in 2017.