Radiation Protection Physics
The Subcritical Assembly in Dubna (SAD) project has been completed, in which the LRB participated in designing radiation shielding. A great amount of calculations have been performed to evaluate the radiation conditions in the rooms of the subcritical assembly building taking into account different radiation sources: 660-MeV proton beam losses in the transportation beam and in magnetic optics elements, neutron leakage from the assembly core shielding, and neutron leakage from the continuous shielding of the phasotron of the Laboratory of Nuclear Problems (LNP). On the grounds of these results, the radiation dose distribution has been determined inside the assembly building for different operation modes. The neutron dose outside the LNP phasotron has been calculated; material and air activation inside the magnet room and the activity of the emissions into the atmosphere have been estimated. Measurements have been done of the spatial distribution of the dose of the neutrons leaking from the phasotron shielding at the SAD construction site and the induced activity of the rampart soil around the phasotron building.
The calculations and design of neutron shielding have been performed for a mobile and stationary customs supervision devices of detecting hidden drugs and explosives.
Studies of the response function of different radiation detectors have been continued. Calculations have been completed of the sensitivity of a multi-sphere spectrometer of neutrons with energy up to 20 MeV. Calculations of the efficiency of X-ray registration by silicon and scintillation detectors have been performed.
In the framework of the cooperation between JINR and the Institute of Cosmic Research, Moscow, on the program of studying planets using nuclear spectroscopy techniques, preliminary estimations of the performances of the LEND device for scanning the Moon's surface have been done.
Three radiobiological experiments at the nuclotron (with 480 MeV/n carbon nuclei and 1 GeV protons) as well as at the U400M (boron-11 nuclei with energy 37 MeV/n) were carried out in 2005. During the runs patterns of human blood lymphocytes and eye proteins were irradiated.In 2005, performed were three radiobiological experiments at the Nuclotron (at a carbon nucleus beam with the energy of 480 MeV/nucleon and at a 1-GeV proton beam) and an experiment at the MC-400 cyclotron (a beam of 11B nuclei with the energy of 37 MeV/nucleon), in which irradiated were human lymphocytes and eye proteins.