Conceptual design of accelerator driven systems with light ion beams

The superior energy efficiency of light ion beams instead of proton beams for energy production in accelerator driven systems (ADS) is demonstrated. The energy efficiency is characterized by the energy gain calculated as the ratio of the energy released in the target to the energy spent for the beam acceleration. The energy deposited in the target is obtained via Geant4 simulation. A method to calculate the energy spent for the beam acceleration by scaling from the data for a reference beam is presented. The influence of the target structure on the energy efficiency of 0.5 - 4 GeV proton beams and 0.25 1 AGeV light ion beams is studied. The target consists of rods with different composition (metal, oxide, carbide) and different levels of enrichment in order to implement the target with a criticality coefficient keff of 0.96 - 0.97, which ensure safe operation. The influence of the rod dimensions, the coolant and converter on the neutron spectrum and energy released are analysed

Creation of the precision magnetic spectrometer SCAN-3

The new JINR project [1] is aimed at studies of highly excited nuclear matter created in nuclei by a high-energy deuteron beam. The matter is studied through observation of its particular decay products - pairs of energetic particles with a wide opening angle, close to 180°. The new precision hybrid magnetic spectrometer SCAN-3 is to be built for detecting charged (π±, K±, p) and neutral (n) particles produced at the JINR Nuclotron internal target in dA collisions. One of the main and complex tasks is a study of low-energy ηA interaction and a search for η-bound states (η-mesic nuclei). Basic elements of the spectrometer and its characteristics are discussed in the article

Study of neutron spectra in extended uranium target. New experimental data

The spatial distribution of neutron fluences in the extended uranium target (“Quinta” assembly) irradiated with 0.66 GeV proton, 4 AGeV deuteron and carbon beams was studied using the reactions with different threshold energy (Eth). The data sets were obtained with 59Co samples. The accumulation rates for the following isotopes: 60Co (Eth 0 MeV), 59Fe (Eth 3 MeV), 58Co (Eth 10 MeV), 57Co (Eth 20 MeV), 56Co (Eth 32 MeV), 47Sc (Eth 55 MeV), and 48V (Eth 70 MeV) were measured with HPGe spectrometer. The experimental accumulation rates were compared with the predictions of the simulations with Geant4 code. Substantial difference between the reconstructed and the simulated data for the hard part of the neutron spectrum was analyzed

Light ion beams for ADS energy production

The comparative analysis and optimization of the energy efficiency for proton and ion beams in ADS systems is performed via GEANT4 simulation with account of energy consumption for different accelerator types. It is demonstrated that for light nuclei, beginning from 7Li, with energies above 1 GeV/nucleon ion beams are substantially more efficient than 1–3 GeV proton beams