The accelerator-Driven-System (ADS) is very important to study the neutron field and radionuclide production inside simple-geometry uranium subcritical setups irradiated with high energy particle beams. A subcritical setup QUINTA was irradiated with the 660-MeV proton beam from Phasotron accelerator at the Joint Institute for Nuclear Research (JINR). The radionuclide production in the region along the beam axis was investigated by the activation technique. The aim was to compare (n,x) with (p,x) reactions using activation detectors of 59 Co and nat Pb, and compare experimental results with the calculated results using Monte Carlo simulation code MCNPX 2.7.

Several simple accelerator-driven system (ADS) setups were irradiated by relativistic proton and deuteron beams in last years at the Nuclotron synchrotron site of the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. This paper is dedicated to a 4 GeV deuteron irradiation of a setup called Energy plus Transmutation (E+T), consisting of a lead target, natural uranium blanket, and polyethylene shielding. This paper represents the finalization of data analysis and concludes systematics of the proton and deuteron experiments carried out with the E+T setup. Activation detectors served for monitoring of proton and deuteron beams and for measurements of neutron field distribution in model ADS studies. Products of reactions with thresholds up to 106 MeV as well as non-threshold reactions were observed in the samples. The yields of the produced isotopes were determined using the gamma-ray spectrometry and compared with Monte Carlo simulations performed with the MCNPX transport code.

The international collaboration Energy and Transmutation of Radioactive Waste (E&T RAW) performed intensive studies of several simple accelerator-driven system (ADS) setups consisting of lead, uranium and graphite which were irradiated by relativistic proton and deuteron beams in the past years at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. The most recent setup called Quinta, consisting of natural uranium target-blanket and lead shielding, was irradiated by deuteron beams in the energy range between 1 and 8 GeV in three accelerator runs at JINR Nuclotron in 2011 and 2012 with yttrium samples among others inserted inside the setup to measure the neutron flux in various places. Suitable activation detectors serve as one of possible tools for monitoring of proton and deuteron beams and for measurements of neutron field distribution in ADS studies. Yttrium is one of such suitable materials for monitoring of high energy neutrons. Various threshold reactions can be observed in yttrium samples. The yields of isotopes produced in the samples were determined using the activation method. Monte Carlo simulations of the reaction rates leading to production of different isotopes were performed in the MCNPX transport code and compared with the experimental results obtained from the yttrium samples.

The possibility of medical radionuclide Cu-64,Cu-67 production in spallation neutron spectrum induced by proton and deuteron beams has been studied. Experiments were performed on a massive natural uranium target at the accelerators Phasotron and Nuclotron JINR, Dubna. The main disadvantage of this method is a high Cu-64/Cu-67 ratio in the final product at EOB. Significantly reduce Cu-64/Cu-67 ratio is only possible if you use zinc target enriched with Zn-68 or Zn-67. The MCNPX simulation of Cu-67,Cu-64 production and definition of the theoretical limit of the specific activity of Cu-67,Cu-64 by irradiation of natural zinc and zinc enriched by the 68 isotope were performed. The neutron flux density shouldnot be less than 5.10(13) n/cm(2)/s if we want to obtain high specific activity (>200 GBq/mg) of Cu-67.

Improvements of the Monte Carlo transport codes and cross-section libraries are very important steps towards usage of the accelerator-driven transmutation systems. We have conducted a lot of benchmark experiments with different set-ups consisting of lead, natural uranium and moderator irradiated by relativistic protons and deuterons within framework of the collaboration "Energy and Transmutation of Radioactive Waste". Unfortunately, the knowledge of the total or partial cross-sections of important reactions is insufficient. Due to this reason we have started extensive studies of different reaction cross-sections. We measure cross-sections of important neutron reactions by means of the quasi-monoenergetic neutron sources based on the cyclotrons at Nuclear Physics Institute in Rez and at The Svedberg Laboratory in Uppsala. Measurements of partial cross-sections of relativistic deuteron reactions were the second direction of our studies. The new results obtained during last years will be shown. Possible use of these data for improvement of libraries, models and benchmark studies will be discussed.

The cross-sections of relativistic deuteron reactions on natural copper were studied in detail by means of activation method. The copper foils were irradiated during experiments with the model spallation targets in the Joint Institute for Nuclear Research. The irradiation of activation samples was performed by beams in the energy range from 1 to 8 GeV. Residual nuclides were measured by the gamma spectrometry. While the EXFOR database contains sets of data for relativistic proton reactions, data for deuteron reactions in this energy range are almost missing. Lack of such experimental cross-section values prevents the use of copper foils from beam integral monitoring. For this reason our experiments focused on their measurement and completely new data were obtained in the energy region where no experimental data have been available so far. The copper monitors with their low sensitivity to fast neutrons will contribute to improvement of the beam integral determination during accelerator-driven system studies.

Experiments with the natural uranium target assembly “QUINTA” exposed to 4 and 8GeV deuteron beams of the Nuclotron accelerator at the Joint Institute for Nuclear Research (Dubna) are analyzed. The reaction rates of 27Al(n,y1)24Na, 27Al(n,y2)22Na and 27Al(n,y3)7Be reactions with effective threshold energies of 5, 27, and 119 MeV were measured at both 4GeV and 8GeV deuteron beam energies. The average neutron fluxes between the effective threshold energies and the effective ends of the neutron spectra (which are 800 or 1000 MeV for 4 or 8GeV deuterons) were determined. The evidence for the intensity shift of the neutron spectra to higher neutron energies with the increase of the deuteron energy from 4GeV to 8GeV was found from the ratios of the average neutron fluxes. The reaction rates and the average neutron fluxes were calculated with the MCNPX 2.7 code.

The low-lying 0+ excited states remain an object of particular interest in the nuclear structure physics. Recently long sets of 0+ excited states were experimentally observed. Our analysis of the experimental data have shown that in even-even nuclei of the rare-earth and actinide regions the energies of all low lying 0+ excited states with great accuracy can be distributed on parabolic functions of the number of monopole excitations building these states. Along with the classification of the energies of the 0+ excited states in respect to the number of bosons that build the band heads we analyze the role of their collectivity in the structure and evolution of the yrast bands and the B(E2) transition probabilities within these bands. The experimental determination in 160Dy of the predicted in this way 0+ excited state with energy 0.6813 MeV is presented.

Recoil studies in the reaction of protons and deuterons with the enriched isotope 118 Sn. Abstract The recoil properties of the product nuclei from the interaction of 3.65 GeV/nucleon protons and deuterons with 118 Sn target have been studied by the method of catching foils on the beams of LHE JINR. The mathematical formalism of the standard two step vector model was used for the analysis of experimental results. The obtained results for the protons are compared with the ones obtained for the deuterons. The total energy of the deuterons beam was 3.65GeV/nucleon. It is interesting to note that the forward velocity v and the recoil nuclei kinetic energy increases linearly with the increase of mass loss of target ∆A, but seems to change its slope at around ∆A = 60. It seems that light and medium mass products are produced partly by multifragmentation mechanism.

Recoil studies in the reaction of protons and deuterons with the enriched isotope 118 Sn. Abstract The recoil properties of the product nuclei from the interaction of 3.65 GeV/nucleon protons and deuterons with 118 Sn target have been studied by the method of catching foils on the beams of LHE JINR. The mathematical formalism of the standard two step vector model was used for the analysis of experimental results. The obtained results for the protons are compared with the ones obtained for the deuterons. The total energy of the deuterons beam was 3.65GeV/nucleon. It is interesting to note that the forward velocity v and the recoil nuclei kinetic energy increases linearly with the increase of mass loss of target ∆A, but seems to change its slope at around ∆A = 60. It seems that light and medium mass products are produced partly by multifragmentation mechanism.

An intensive beam of 660 MeV protons was directed towards a lead target (not surrounded by shielding or neutron reflectors) for 10 minutes. On the top of the target were placed detectors and iodine samples. The neutron field and the transmutation of I were studied by the neutron activation analysis method. First simulations were compared to the experimental data. 1 Description of the experiment The collaboration ”Energy plus transmutation” works on benchmark experiments intended to test simulation programs, which shall be used in design of Accelerator Driven Systems. The work consist of a series of similar experiments, of which each is concentrated on a specific topic. Generally said, we study production of neutrons by spallation reactions on massive targets, their transport, and use for transmutation. Our experimental setups consist of heavy metal (Pb, W, Bi, U) targets of cylindrical shape to which a narrow beam of relativistic protons is directed. In the target protons cause spallations of heavy nuclei to nucleons, and smaller fractions of nucleus. Relativistic nucleons cause further spallations, and mostly neutrons of all energies from thermal up to the energy of the proton beam exit the target sideways. Such neutron production shall be used in the devices called ADS (Accelerator Driven Systems), which will be able to use a wider spectrum of nuclear fuel (Th, nuclear waste from thermal reactors), and their waste should be much less radioactive than the waste from thermal reactors. These systems cannot be built in smaller scale as a test model, and the accelerators to be added to the reactors will not be a cheap extension. That is why we need the precise descriptions of what will be going on in these systems. Our experiments are simplified setups of them, and are used as benchmark tests for the computer simulations that will be used to describe larger and more complicated systems. One of the experiments was held on Dubna Phasotron in December, 2003, and was focused on the studies of short-lived iodine isotopes production. We needed to make our measurements as soon as possible after the irradiation, and use as intensive proton beam as possible. The proton beam was provided by Dubna Phasotron, which accelerated the intensive proton beam to the energy 660 MeV. The beam was directed to the bare lead