SECOND INTERNATIONAL ULAANBAATAR CONFERENCE ON NUCLEAR PHYSICS AND APPLICATIONS
1342(2011); http://dx.doi.org/10.1063/1.3583159View Description Hide Description
Proton Accelerator (PA) Project is at a stage of development, working towards a Technical Design Report under the roof of a larger‐scale Turkish Accelerator Center (TAC) Project. The project is supported by the Turkish State Planning Organization. The PA facility will be constructed in a series of stages including a 3 MeV test stand, a 55 MeV linac which can be extended to MeV, and then a full 1–3 GeV proton synchrotron or superconducting linac. In this article, science applications, overview, and current status of the PA Project will be given.
1342(2011); http://dx.doi.org/10.1063/1.3583160View Description Hide Description
The reaction was measured from to 15 MeV at the Los Alamos Neutron Science Cemter (LANSCE). The γ rays were detected with the Compton‐suppressed Germanium Array for Neutron Induced Excitations (GEANIE). Measured γ‐ray excitation functions were converted to partial γ‐ray cross sections, Twenty four individual γ‐rays up to in were measured. Results are compared with enhanced Hauser Feshbach model calculations: the spin distribution in the pre‐equilibrium reaction is calculated with the quantum mechanical model of Feshbach, Kerman and Koonin. The particle transmission coefficients were calculated with two different global optical model potential parameter sets. We employed the coupled‐channel optical model based on the soft rotor model and with spherical potential.
1342(2011); http://dx.doi.org/10.1063/1.3583161View Description Hide Description
The experimental observation of proton radioactivity has provided a unique possibility to access exotic nuclei at the proton drip‐line. A theoretical approach was developed to interpret the data, and predict the shape and structure of such neutron deficient nuclei. The present studies provide new and precise tools to access nuclear structure properties far from the stability domain.
1342(2011); http://dx.doi.org/10.1063/1.3583162View Description Hide Description
Improved neutron‐capture γ‐ray spectra, not only of interest to the nuclear structure and reactions communities, are needed in a variety of applied and non‐proliferation programs. This requires an evaluation of the existing experimental capture‐γ data. Elemental neutron‐capture data taken from direct measurements at the Budapest Reactor have been used to collate the Evaluated Gamma‐ray Activation File, a database of capture γ‐ray cross sections. These cross sections are then compared to Monte Carlo simulations of γ‐ray emission following the thermal neutron‐capture process using the statistical‐decay code DICEBOX. The aim of this procedure is to obtain the total radiative neutron‐capture cross section and confidently increase the number of levels and γ rays that can be assigned to a given isotope in the neutron data libraries. To achieve these goals and provide as complete information as possible in the neutron data libraries, it is also necessary to remain current with recent advances in nuclear structure physics and ensure that the latest data in the Evaluated Nuclear Structure Data File has been taken into consideration. This way an optimal level scheme can be derived by comparison with simulations and available experimental data. New information derived from this study can then be used to improve the nuclear structure and reactions databases with more‐complete level schemes, and indeed, provide reliable and accurate input to a variety of applications which require this information. Recent results from neutron capture on the stable tungsten isotopes are presented to illustrate the evaluation process.
1342(2011); http://dx.doi.org/10.1063/1.3583163View Description Hide Description
J‐PARC is a research center with a high intensity proton accelerator consisting of a proton LINAC, 3 GeV and 50 GeV synchrotrons, located at Tokai, Japan. High intensity neutron and muon beams produced by 3 GeV protons are employed for material and biological science. A neutrino and hadron beams provided by 50 GeV protons are used for nuclear and particle physics. J‐PARC construction was completed last year and various researches have started. We report the present status of the J‐PARC project and describe its perspective with an emphasis on the nuclear and particle physics.
1342(2011); http://dx.doi.org/10.1063/1.3583164View Description Hide Description
We applied the Brueckner theory to the Antisymmetrized Molecular Dynamics (AMD) and examined the reliability of the AMD calculations based on realistic nuclear interactions. In this method, the Bethe‐Goldstone equation in the Brueckner theory is solved for every nucleon pair described by wave packets of AMD, and the G‐matrix is calculated with single‐particle orbits in AMD self‐consistently. We apply this framework to not only α‐nuclei but also nuclei with It is confirmed that these results present the description of reasonable cluster structures and energy‐level schemes comparable with the experimental ones in light nuclei.
1342(2011); http://dx.doi.org/10.1063/1.3583165View Description Hide Description
Recent experimental work at the TRIUMF‐ISAC radioactive ion‐beam facility in Vancouver Canada, has produced several new results related to precise experimental tests of fundamental symmetries. The nature of these programs range from campaigns using existing setups, to the development of new apparati to further the experimental reach. One of the primary goals has been the investigation of superallowed Fermi β‐decay, and its relation to Standard Model tests of CVC and CKM unitarity The extraction of experimental β‐decay ft values requires the measurement of three quantities: the half‐life, the superallowed branching ratio, and the parent‐daughter mass difference. TRIUMF‐ISAC has the ability to measure each of these values with very high precision, using a gas‐proportional‐counter, the 8π γ‐ray spectrometer, and TITAN, respectively. This report focuses on the recent experimental progress of the superallowed program, as well as highlighting some results from the successful halo‐nucleus mass‐measurement program at TITAN.
1342(2011); http://dx.doi.org/10.1063/1.3583166View Description Hide Description
We present a new method of smoothing discrete breakup cross sections calculated by the method of continuum‐discretized coupled‐channels. In the four‐body breakup reaction of at the continuous breakup cross section is evaluated as a function of the excitation energy of Convergence of the cross section with respect to extending the modelspace is also confirmed.
1342(2011); http://dx.doi.org/10.1063/1.3583167View Description Hide Description
Precision β decay experiments represent an important and complimentary approach to high‐energy searches for physics outside the “Standard Model”, our current understanding of fundamental particles and their interactions. The mirror decay of provides an excellent probe with which to search for new physics. The ft value of this (as well as other mirror transitions) can be used to provide a measurement of the value of the element of the CKM mass‐mixing matrix, complementing the value obtained from superallowed pure Fermi decays. In addition, the polarized angular distribution parameters are sensitive to a variety of possible new physics: the β and ν asymmetries can be used to search for right‐handed currents in the charged weak interaction, and their energy‐dependences are sensitive to second‐class currents forbidden in the Standard Model. Time‐reversal symmetry can also be tested by a precision measurement of the triple‐vector correlation between the initial nuclear spin and the momenta of the leptons. An overview of the variety of physics that can be probed using laser‐cooled and the techniques used to perform the precision measurements is presented.
1342(2011); http://dx.doi.org/10.1063/1.3583168View Description Hide Description
Investigation of charged particle emission reaction cross sections for fast neutrons is important to both nuclear reactor technology and the understanding of nuclear reaction mechanisms. In particular, the study of (n,p) cross sections is necessary to estimate radiation damage due to hydrogen production, nuclear heating and transmutations in the structural materials of fission and fusion reactors. On the other hand, it is often necessary in practice to evaluate the neutron cross sections of the nuclides for which no experimental data are available.
Because of this, we carried out the systematical analysis of known experimental (n,p) and (n,a) cross sections for fast neutrons and observed a systematical regularity in the wide energy interval of 6–20 MeV and for broad mass range of target nuclei. To explain this effect using the compound, pre‐equilibrium and direct reaction mechanisms some formulae were deduced. In this paper, in the framework of the statistical model known experimental (n,p) cross sections averaged over the thermal fission neutron spectrum of U‐235 are analyzed. It was shown that the experimental data are satisfactorily described by the statistical model. Also, in the case of (n,p) cross sections the effective average neutron energy for fission spectrum of U‐235 was found to be around 3 MeV.
Mean‐field plus various types of pairing models and an exact boson mapping of the standard pairing model1342(2011); http://dx.doi.org/10.1063/1.3583169View Description Hide Description
Exact solutions of Nilsson mean‐field with various pairing interactions are reviewed. Some even‐odd mass differences and moments of inertia of low‐lying states for rare earth and actinide nuclei are calculated for the nearest‐orbit pairing approximation as well as for the extended pairing model and compared to available experimental data. An exact boson mapping of the standard pairing Hamiltonian is also reported. Under the mapping, fermion pair operators are mapped exactly onto corresponding bosons. The image of the mapping is a Bose‐Hubbard model with orbit‐dependent hopping.
1342(2011); http://dx.doi.org/10.1063/1.3583170View Description Hide Description
The neutron capture reaction is useful in identifying and analyzing the gamma‐ray spectrum from an unknown assembly as it gives unambiguous information on its composition. This can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma‐ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma‐ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research Project. EGAF is being used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy and is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. We are investigating the capture spectra from higher energy neutrons experimentally using surrogate reactions and modeling this with Hauser‐Feshbach codes. This can then be used to benchmark CASINO, a version of DICEBOX modified for neutron capture at higher energy. This can be used to simulate spectra from neutron capture at incident neutron energies up to 20 MeV to improve the gamma‐ray spectrum in neutron data libraries used for transport modeling of unknown assemblies.
1342(2011); http://dx.doi.org/10.1063/1.3583171View Description Hide Description
High intensity Accelerator is being studied all over world for numerous applications, which includes the waste transmutation, spallation neutron source and material irradiation facilities. The R/D activities of the technology of High intensity accelerator are also developed in China for some year, and have some good facilities around China. This paper will reports the status of some high intensity accelerators and neutron source in China, which including ADS/RFQ; CARR; CSNS; PKUNIFTY & CPHS. This paper will emphatically report the Compact Pulsed Hadron Source (CPHS) led by the Department of Engineering Physics of Tsinghua University in Beijing, China.
1342(2011); http://dx.doi.org/10.1063/1.3583172View Description Hide Description
Asian medicinal herbs Chrysanthemum (Spiraea aquilegifolia Pall.) and Red Sandalwood (Pterocarpus Santalinus) are widely used in folk and Ayurvedic medicine for healing and preventing some diseases. The modern medical science has proved that the Chrysanthemum (Spiraea aquilegifolia Pall.) possesses the following functions: reducing blood press, dispelling cancer cell, coronary artery’s expanding and bacteriostating and Red Sandalwood (Pterocarpus Santalinus) is recommended against headache, toothache, skin diseases, vomiting and sometimes it is taken for treatment of diabetes. Species of Chrysanthemums were collected in the north‐eastern and central Mongolia, and the Red Sandalwood powder was imported from India. Samples of Chrysanthemums (branches, flowers and leaves) (0.5 g) and red sandalwood powder (0.5 g) were subjected to the multi‐element instrumental neutron activation analysis using epithermal neutrons (ENAA) at the IBR‐2 reactor, Frank Laboratory of Neutron Physics (FLNP) JINR, Dubna. A total of 41 elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Cd, Cs, Ba, La, Hf, Ta, W, Sb, Au, Hg, Ce, Nd, Sm, Eu, Tb, Dy, Yb, Th, U, Lu) were determined. For the first time such a large group of elements was determined in the herbal plants used in Mongolia. The quality control of the analytical results was provided by using certified reference material Bowen Cabbage. The results obtained are compared to the “Reference plant» data (B. Markert, 1992) and interpreted in terms of excess of such elements as Se, Cr, Ca, Fe, Ni, Mo, and rare earth elements.
The Investigation of the Rare Metal Content in the Geological Samples from Mongolia on the Iren Facility1342(2011); http://dx.doi.org/10.1063/1.3583173View Description Hide Description
Definition of the content of rare metals in the samples of ore was carried out by the method of the neutron activation analysis. IREN installation which represents the linear electron accelerator and no multiplying tungsten target served as the neutron source. The tungsten target has been located in the centre of the water moderator in diameter 15 cm .
The irradiation has been spent on installation IREN within 8 hours 40 minutes. Electron energy was an order of 30 MeV, a current of an order 5 ‐10 microamperes. Samples settled down on the moderator surface. 2 samples of ore have been irradiated: Os‐1 and Os‐2 and a number of indicators for definition of neutron flux. Weights of indicators did not exceed a several milligrams.
1342(2011); http://dx.doi.org/10.1063/1.3583174View Description Hide Description
Over ninety percent of Mongolia’s energy load is run through the Central Energy System. This primary grid provides Mongolia’s capital, Ulaanbaatar, with the power it uses to function. In the first half of 2010 the Central Energy System managed 1739.45 million kWhs, a 4.6 percent increase from 2009. If this growth rate continues, by 2015 Ulaanbaatar’s three power plants will be unable to generate enough heat and electricity to meet the city’s needs. Currently, plans have been proposed to rehabilitate the aging coal power plants. However, rising maintenance costs and growing emission levels make the long‐term sustainability of this solution uncertain. The following paper analyzes the capital, maintenance, and decommissioning costs associated with the current rehabilitation plans and compares them with a nuclear alternative.
1342(2011); http://dx.doi.org/10.1063/1.3583175View Description Hide Description
The few‐body, especially three‐body, problem is still an open (and therefore interesting) subject in nuclear physics, and has been studied intensively by various theoretical frameworks. The reactions are important not only from the basic interest but also from the application point of view. The nucleus is well described by the cluster model such as and Therefore, it is necessary for us to treat the system with and models. In this work, we study the inelastic reactions applying the cluster model to and using the continuum‐discretized coupled‐channels approach. We have included elastic and inelastic data at 14.1 MeV neutron incident energies in the calculation. At the present energy, our calculation gives almost good agreement with experimental data.
1342(2011); http://dx.doi.org/10.1063/1.3583176View Description Hide Description
The interest in small reactor is growing in US. The construction cost of small reactor depends on the size of the market because one way of the cost reduction will be obtained by the mass production in general. Mongolia, which is one of the potential market of small reactor, is interesting in the utilization of nuclear energy, such as district heating.