27 research outputs found
(n,xn) cross section measurements for Y-89 foils used as detectors for high energy neutron measurements in the deeply subcritical assembly âQUINTAâ
Study of the deep subcritical systems (QUINTA) using relativistic beams is performed within the project âEnergy and Transmutation of Radioactive Wastesâ (E&T â RAW). The experiment assembly was irradiated by deuteron/proton beam (Dubna NUCLOTRON). We calculated the neutron energy spectrum inside the whole assembly by using threshold energy (n,xn) reactions in yttrium (Y-89) foils. There are almost no experimental cross section data for those reactions. New Y-89(n,xn) cross section measurements were carried out at The Svedberg laboratory (TSL) in Uppsala, Sweden in 2015. In this paper we present preliminary results of those experiments
Np-237 transmutation efficiency dependence on beam particle, energy and sample position in QUINTA setup
Np-237 samples were irradiated with spallation neutrons produced at the ADS setup QUINTA. Six experiments were carried out at the JINR, in Dubna â one in carbon (C6+), three in deuteron, and two in proton beams. The energy in carbon was 24 GeV, in deuteron â 2, 4 and 8 GeV, respectively, and 660 MeV in the proton beam. In five cases the sample was located in a side window in a lead shield. In one case (660 MeV proton beam) two samples were located on the top of the QUINTA setup, one â on the top of section 2, and the second one â on the top of section 4. The transmutation study method was based on gamma-ray spectrometry. During the analysis of the spectra several fission products and one actinide were identified. Fission product activities yielded the number of fissions. The actinide (Np-238), a result of neutron capture by Np-237, yielded the number of captures. The main goal of this work was to find out if and how the transmutation rate depended on the accelerator beam and sample location during the irradiation
Perspektywa Wschodnia: Rosja wobec rozszerzenia NATO. Studium przypadku poszerzenia NATO z 1999 i 2004 r.
â[Russia] cannot agree with attempts to move the center of gravity in questions of providing for security on the continent.â Russiaâs Policy for National Security (1996)âThe perspective of NATO enlargement to the East is unacceptable to Russia, because it represents a threat to its security.â Russiaâs Concept of National Security (1997
Poland as a Euro-Atlantic Power the determinants of U.S.-Polish relations 1989-2005
st of its NATO allies, as well as the need to become a valued and effective member of the European Union, despite the latterĂą s setback in the course of 2004 and 2005.http://archive.org/details/polandseuroatlan109451852Approved for public release; distribution is unlimited
Comparison of Graph Fitting and Sparse Deep Learning Model for Robot Pose Estimation
The paper presents a simple, yet robust computer vision system for robot arm tracking with the use of RGB-D cameras. Tracking means to measure in real time the robot state given by three angles and with known restrictions about the robot geometry. The tracking system consists of two parts: image preprocessing and machine learning. In the machine learning part, we compare two approaches: fitting the robot pose to the point cloud and fitting the convolutional neural network model to the sparse 3D depth images. The advantage of the presented approach is direct use of the point cloud transformed to the sparse image in the network input and use of sparse convolutional and pooling layers (sparse CNN). The experiments confirm that the robot tracking is performed in real time and with an accuracy comparable to the accuracy of the depth sensor
Average fast neutron flux in three energy ranges in the Quinta assembly irradiated by two types of beams
This work was performed within the international project âEnergy plus Transmutation of Radioactive Wastesâ (E&T - RAW) for investigations of energy production and transmutation of radioactive waste of the nuclear power industry. 89Y (Yttrium 89) samples were located in the Quinta assembly in order to measure an average high neutron flux density in three different energy ranges using deuteron and proton beams from Dubna accelerators. Our analysis showed that the neutron density flux for the neutron energy range 20.8 - 32.7 MeV is higher than for the neutron energy range 11.5 - 20.8 MeV both for protons with an energy of 0.66 GeV and deuterons with an energy of 2 GeV, while for deuteron beams of 4 and 6 GeV we did not observe this
Average fast neutron flux in three energy ranges in the Quinta assembly irradiated by two types of beams
This work was performed within the international project âEnergy plus Transmutation of Radioactive Wastesâ (E&T - RAW) for investigations of energy production and transmutation of radioactive waste of the nuclear power industry. 89Y (Yttrium 89) samples were located in the Quinta assembly in order to measure an average high neutron flux density in three different energy ranges using deuteron and proton beams from Dubna accelerators. Our analysis showed that the neutron density flux for the neutron energy range 20.8 - 32.7 MeV is higher than for the neutron energy range 11.5 - 20.8 MeV both for protons with an energy of 0.66 GeV and deuterons with an energy of 2 GeV, while for deuteron beams of 4 and 6 GeV we did not observe this
Comparison of neutron induced fission and capture in Np-237 and Pu-239 irradiated in QUINTA assembly with 660 MeV proton beam
Two Np-237 samples and one Pu-239 were irradiated in spallation neutrons produced in ADS setup QUINTA. The accelerated beam consisted of protons of energy 660 MeV. The method was based on gamma-ray spectrometry measurement. During analysis of the spectra several fission products and one actinide were identified. Fission product activities gave the number of fissions. The actinide (Np-238), a result of neutron capture by Np-237 gave the number of captures. In a similar manner the number of fissions in Pu-239 was determined. The Pu-240, a product of neutron capture by Pu-239, activity was impossible to measure