Unified model of nuclear mass and level density formulas

International Nuclear Information System (INIS)

Nakamura, Hisashi

2001-01-01

The objective of present work is to obtain a unified description of nuclear shell, pairing and deformation effects for both ground state masses and level densities, and to find a new set of parameter systematics for both the mass and the level density formulas on the basis of a model for new single-particle state densities. In this model, an analytical expression is adopted for the anisotropic harmonic oscillator spectra, but the shell-pairing correlation are introduced in a new way. (author)

A q deformation of Gell-Mann-Okubo mass formula

International Nuclear Information System (INIS)

Bagchi, B.; Biswas, S.N.

1996-01-01

We explore the possibility of deforming Gell-Mann-Okubo (GMO) mass formula within the framework of a quantized enveloping algebra. A small value of the deformation parameter is found to provide a good fit to the observed mass spectra of the π, K and η, mesons. (author). 13 refs

Scission-point model of nuclear fission based on deformed-shell effects

International Nuclear Information System (INIS)

Wilkins, B.D.; Steinberg, E.P.; Chasman, R.R.

1976-01-01

A static model of nuclear fission is proposed based on the assumption of statistical equilibrium among collective degrees of freedom at the scission point. The relative probabilities of formation of complementary fission fragment pairs are determined from the relative potential energies of a system of two nearly touching, coaxial spheroids with quadrupole deformations. The total potential energy of the system at the scission point is calculated as the sum of liquid-drop and shell- and pairing-correction terms for each spheroid, and Coulomb and nuclear potential terms describing the interaction between them. The fissioning system at the scission point is characterized by three parameters: the distance between the tips of the spheroids (d), the intrinsic excitation energy of the fragments (tau/sub int/), and a collective temperature (T/sub coll/). No attempt is made to adjust these parameters to give optimum fits to experimental data, but rather, a single choice of values for d, tau/sub int/, and T/sub coll/ is used in the calculations for all fissioning systems. The general trends of the distributions of mass, nuclear charge, and kinetic energy in the fission of a wide range of nuclides from Po to Fm are well reproduced in the calculations. The major influence of the deformed-shell corrections for neutrons is indicated and provides a convenient framework for the interpretation of observed trends in the data and for the prediction of new results. The scission-point configurations derived from the model provide an interpretation of the ''saw-tooth'' neutron emission curve as well as previously unexplained observations on the variation of TKE for isotopes of U, Pu, Cm, and Cf; structure in the width of total kinetic energy release as a function of fragment mass ratio; and a difference in threshold energies for symmetric and asymmetric mass splits in the fission of Ra and Ac isotopes

Nucleus spectroscopy: extreme masses and deformations

International Nuclear Information System (INIS)

Theisen, Ch.

2009-12-01

The author proposes a synthesis of research activities performed since 1995 in the field of experimental nuclear physics, and more particularly in the investigation of two nucleus extreme states: deformation on the one hand, heavy and very heavy nuclei on the other hand. After a presentation of the context of investigations on deformation, rotation, and heavy nuclei, he gives an overview of developments regarding instruments (gamma spectrometers, detection of fission fragments, and detection at the focal plane of spectrometers or separators) and analysis techniques. Experiments and results are then reported and discussed, concerning super-deformed states with a high angular moment, spectroscopy of neutron-rich nuclei, very heavy nuclei close to nucleus map borders. He finally draws perspectives for middle and long term studies on the heaviest nuclei

Deformed nuclear state as a quasiparticle-pair

International Nuclear Information System (INIS)

Dobaczewski, J.; Skalski, J.

1988-01-01

The deformed nuclear states, obtained in terms of the Hartree-Fock plus BCS method with the Skyrme SIII interaction, are approximated by condensates of the low-angular-momentum quasiparticle and particle pairs. The optimal pairs are determined by the variation after truncation method. The influence of the truncation on the deformation energy and the importance of the core-polarization effects are investigated

Role of deformed shell effects on the mass asymmetry in nuclear fission of mercury isotopes

International Nuclear Information System (INIS)

Panebianco, Stefano; Sida, Jean-Luc; Goutte, Heloise; Lemaitre, Jean-Francois; Dubray, Noel; Hilaire, Stephane

2012-01-01

Until now, the mass asymmetry in the nuclear fission process has been understood in terms of the strong influence of the nuclear structure of the nascent fragments. Recently, a surprising asymmetric fission has been discovered in the light mercury region and has been interpreted as the result of the influence of the nuclear structure of the parent nucleus, totally discarding the influence of the fragments' structure. To assess the role of the fragment shell effects in the mass asymmetry in this particular region, a scission-point model, based on a full energy balance between the two nascent fragments, has been developed using one of the best theoretical descriptions of microscopic nuclear structure. As for actinides, this approach shows that the asymmetric splitting of the Hg-180 nucleus and the symmetric one of Hg-198 can be understood on the basis of only the microscopic nuclear structure of the fragments at scission. (authors)

Glueball masses for the deformed conifold theory

International Nuclear Information System (INIS)

Caceres, Elena; Hernandez, Rafael

2000-11-01

We obtain the spectrum of glueball masses for the N=1 non-conformal cascade theory whose supergravity dual was recently constructed by Klebanov and Strassler. The glueball masses are calculated by solving the supergravity equations of motion for the dilaton and the two-form in the deformed conifold background. (author)

Relative scale and the strength and deformability of rock masses

Science.gov (United States)

Schultz, Richard A.

1996-09-01

The strength and deformation of rocks depend strongly on the degree of fracturing, which can be assessed in the field and related systematically to these properties. Appropriate Mohr envelopes obtained from the Rock Mass Rating (RMR) classification system and the Hoek-Brown criterion for outcrops and other large-scale exposures of fractured rocks show that rock-mass cohesive strength, tensile strength, and unconfined compressive strength can be reduced by as much as a factor often relative to values for the unfractured material. The rock-mass deformation modulus is also reduced relative to Young's modulus. A "cook-book" example illustrates the use of RMR in field applications. The smaller values of rock-mass strength and deformability imply that there is a particular scale of observation whose identification is critical to applying laboratory measurements and associated failure criteria to geologic structures.

The deformation behavior of soil mass in the subsidence region of Beijing, China

Directory of Open Access Journals (Sweden)

F. Tian

2015-11-01

Full Text Available Land subsidence induced by excessive groundwater withdrawal has been a major environmental and geological problem in the Beijing plain area. The monitoring network of land subsidence in Beijing has been established since 2002 and has covered the entire plain area by the end of 2008. Based on data from extensometers and groundwater observation wells, this paper establishes curves of variations over time for both soil mass deformation and water levels and the relationship between soil mass deformation and water level. In addition, an analysis of deformation behavior is carried out for soil mass with various lithologies at different depths depending on the corresponding water level. Finally, the deformation behavior of soil mass is generalized into five categories. The conclusions include: (i the current rate of deformation of the shallow soil mass is slowing, and most of the mid-deep and deep soil mass continue to compress at a more rapid speed; (ii the sand strata behaves elastically, while the clay soil mass at different depths is usually characterized by elastic-plastic and creep deformation, which can be considered as visco-elastoplastic.

Calculation of nuclear level density parameters of some light deformed medical radionuclides using collective excitation modes of observed nuclear spectra

International Nuclear Information System (INIS)

Okuducu, S.; Sarac, H.; Akti, N. N.; Boeluekdemir, M. H.; Tel, E.

2010-01-01

In this study the nuclear energy level density based on nuclear collective excitation mechanism has been identified in terms of the low-lying collective level bands at near the neutron binding energy. Nuclear level density parameters of some light deformed medical radionuclides used widely in medical applications have been calculated by using different collective excitation modes of observed nuclear spectra. The calculated parameters have been used successfully in estimation of the neutron-capture cross section basic data for the production of new medical radionuclides. The investigated radionuclides have been considered in the region of mass number 40< A< 100. The method used in the present work assumes equidistance spacing of the collective coupled state bands of the interest radionuclides. The present calculated results have been compared with the compiled values from the literatures for s-wave neutron resonance data.

Survey of odd-odd deformed nuclear spectroscopy

International Nuclear Information System (INIS)

Hoff, R.W.

1993-01-01

In this paper, we survey the current experimental data that support assignment of rotational bands in odd-odd deformed nuclear in the rare earth and actinide regions. We present the results of a new study of 170 Mt nuclear structure. In a comparing experimental and calculated Gallagher-Moszkowski matrix elements for rare earth-region nuclei, we have developed a new approach to the systematics of these matrix elements

Mechanical stability of the cell nucleus: roles played by the cytoskeleton in nuclear deformation and strain recovery.

Science.gov (United States)

Wang, Xian; Liu, Haijiao; Zhu, Min; Cao, Changhong; Xu, Zhensong; Tsatskis, Yonit; Lau, Kimberly; Kuok, Chikin; Filleter, Tobin; McNeill, Helen; Simmons, Craig A; Hopyan, Sevan; Sun, Yu

2018-05-18

Extracellular forces transmitted through the cytoskeleton can deform the cell nucleus. Large nuclear deformation increases the risk of disrupting the nuclear envelope's integrity and causing DNA damage. Mechanical stability of the nucleus defines its capability of maintaining nuclear shape by minimizing nuclear deformation and recovering strain when deformed. Understanding the deformation and recovery behavior of the nucleus requires characterization of nuclear viscoelastic properties. Here, we quantified the decoupled viscoelastic parameters of the cell membrane, cytoskeleton, and the nucleus. The results indicate that the cytoskeleton enhances nuclear mechanical stability by lowering the effective deformability of the nucleus while maintaining nuclear sensitivity to mechanical stimuli. Additionally, the cytoskeleton decreases the strain energy release rate of the nucleus and might thus prevent shape change-induced structural damage to chromatin. © 2018. Published by The Company of Biologists Ltd.

Order and chaos in nuclear and metal cluster deformation

International Nuclear Information System (INIS)

Radu, S.

1995-08-01

The vast amount of nuclear and metal cluster data indicates that shell structure and deformation are two simultaneous properties. A conflicting situation is therefore encountered as the shell structure, a firm expression of order, is apparently not compatible with the non-integrable nature of the models incorporating deformation. The main issue covered in this thesis is the intricate connection between deformation and chaotic behaviour in deformation models pertinent to nuclear structure and metal cluster physics. It is shown that, at least in some cases, it is possible to reconcile the occurrence of shell structure with non-integrability. The coupling of an axially deformed harmonic oscillator to an axially symmetric octupole term renders the problem non-integrable. The chaotic character of the motion is strongly dependent on the type of deformation, in that a prolate shape shows virtually no chaos, while in an oblate case the motion exhibits fully developed chaos when the octupole term is switched on. Whereas the problem is non-integrable, the quantum mechanical spectrum nevertheless shows some shell structure in the prolate case for particular, yet fairly large octupole strengths; for spherical or oblate deformation the shell structure disappears. This result is explained in terms of classical periodic orbits which are found by employing the 'removal of resonances method'. Particular emphasis is put on the effect of the hexadecapole deformation which is important in fission processes. The combined effect of octupole and hexadecapole deformation leads to important conclusions for the experimental work as a high degree of ambiguity is signaled for the interpretation of data. The ambiguity results from the discovery of a mutual cancellation of the octupole and hexadecapole deformation in prolate superdeformed systems. The phenomenological Nilsson model is treated in a similar way. It is argued that while in nuclei it produces good results for the low-lying levels

Quantum deformations of conformal algebras with mass-like deformation parameters

International Nuclear Information System (INIS)

Frydryszak, Andrzej; Lukierski, Jerzy; Mozrzymas, Marek; Minnaert, Pierre

1998-01-01

We recall the mathematical apparatus necessary for the quantum deformation of Lie algebras, namely the notions of coboundary Lie algebras, classical r-matrices, classical Yang-Baxter equations (CYBE), Froebenius algebras and parabolic subalgebras. Then we construct the quantum deformation of D=1, D=2 and D=3 conformal algebras, showing that this quantization introduce fundamental mass parameters. Finally we consider with more details the quantization of D=4 conformal algebra. We build three classes of sl(4,C) classical r-matrices, satisfying CYBE and depending respectively on 8, 10 and 12 generators of parabolic subalgebras. We show that only the 8-dimensional r-matrices allow to impose the D=4 conformal o(4,2)≅su(2,2) reality conditions. Weyl reflections and Dynkin diagram automorphisms for o(4,2) define the class of admissible bases for given classical r-matrices

Mass deformed ABJM theory on three sphere in large N limit

Energy Technology Data Exchange (ETDEWEB)

Nosaka, Tomoki [Korea Institute for Advanced Study,Seoul 02455 (Korea, Republic of); Shimizu, Kazuma; Terashima, Seiji [Yukawa Institute for Theoretical Physics, Kyoto University,Kyoto 606-8502 (Japan)

2017-03-23

In this paper the free energy of the mass deformed ABJM theory on S{sup 3} in the large N limit is studied. We find a new solution of the large N saddle point equation which exists for an arbitrary value of the mass parameter, and compute the free energies for these solutions. We also show that the solution corresponding to an asymptotically AdS{sub 4} geometry is singular at a certain value of the mass parameter and does not exist over this critical value. It is not clear that what is the gravity dual of the mass deformed ABJM theory on S{sup 3} for the mass parameter larger than the critical value.

Mass deformed world-sheet action of semi local vortices

Energy Technology Data Exchange (ETDEWEB)

Jiang, Yunguo [School of Space Science and Physics, Shandong University at Weihai,264209 Weihai (China); Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment,264209 Weihai (China)

2014-02-10

The mass deformed effective world-sheet theory of semi local vortices was constructed via the field theoretical method. By Euler-Lagrangian equations, the Ansatze for both the gauge field and the adjoint scalar were solved, this ensures that zero modes of vortices are minimal excitations of the system. Up to the 1/g{sup 2} order, all profiles are solved. The mass deformed effective action was obtained by integrating out the transverse plane of the vortex string. The effective theory interpolates between the local vortex and the lump. Respecting certain normalization conditions, the effective theory shows a Seiberg-like duality, which agrees with the result of the Kähler quotient construction.

Integrated analysis of rock mass deformation within shaft protective pillar

Directory of Open Access Journals (Sweden)

Ewa Warchala

2016-01-01

Full Text Available The paper presents an analysis of the rock mass deformation resulting from mining in the vicinity of the shaft protection pillar. A methodology of deformation prediction is based on a deterministic method using Finite Element Method (FEM. The FEM solution is based on the knowledge of the geomechanical properties of the various geological formations, tectonic faults, types of mining systems, and the complexity of the behaviour of the rock mass. The analysis gave the stress and displacement fields in the rock mass. Results of the analysis will allow for design of an optimal mining system. The analysis is illustrated by an example of the shaft R-VIII Rudna Mine KGHM Polish Copper SA.

Detection of surface deformation and ionospheric perturbation by the North Korea nuclear test

Science.gov (United States)

Park, S. C.; Lee, W. J.; Sohn, D. H.; Lee, D. K.; Jung, H. S.

2017-12-01

We used remote sensing data to detect the changes on surface and ionosphere due to the North Korea nuclear test. To analyze the surface deformation before and after the 6th North Korea (NK) nuclear test, we used Satellite Aperture Radar (SAR) images. It was reported that there were some surface deformation with about 10 cm by the 4th test (Wei, 2017) and the 5th test (Jo, 2017) using Interferometric SAR (InSAR) technique. However we could not obtain surface deformation by the 6th test using InSAR with Advanced Land Observation Satellite 2 (ALOS-2) data because of low coherence in the area close to the epicenter. Although the low coherence can be occurred due to several reasons, the main reason may be large deformation in this particular case. Therefore we applied pixel offset method to measure the amount of surface deformation in the area with low coherence. Pixel offset method calculates the deformation in the directions along track and Line-of-Sight (LOS) using cross correlation of intensity of two SAR images before and after the event for a pixel and is used frequently to obtain large deformation of glacier (e.g. Lee et al., 2015). Applying pixel offset method to the area of the 6th NK nuclear test, we obtained about 3 m surface deformation in maximum. It seems that the larger deformation occurs as the mountain slope is steeper.We then analyzed ionospheric perturbation using Global Navigation Satellite System (GNSS) data. If acoustic wave by a nuclear test goes up to the ionosphere and disturbs electron density, then the changes in slant total electron content (STEC) may be detected by GNSS satellites. STEC perturbation has been reported in the previous NK nuclear tests (e.g. Park et al., 2011). We analyzed the third order derivatives of STEC for 51 GNSS stations in South Korea and found that some perturbation were appeared at 4 stations about 20 40 minutes after the test.

Nuclear structure studies in A∼100 and A∼130 mass regions

International Nuclear Information System (INIS)

Sihotra, S.

2012-01-01

This paper reports the nuclear structure studies in the mass A∼ 100 and A∼130 regions. The investigations were performed in 98,99 Rh, 99 Pd, 96 Tc, 106,107 In, and 129,131 Cs nuclei near the proton (Z = 50) and neutron (N = 50, 64) shell closures with a view to understand the structural features that result from interplay between single particle and collective degrees of freedom. The nuclei in these regions are characterized by a small quadrupole deformation and soft to gamma deformation at low spins. In order to compare experimental results directly with the theoretical calculations, the experimental spins and level energies have been transformed into the rotating (intrinsic) frame of nucleus. The level schemes have been interpreted in the framework of theoretical model calculations. Configurations assigned to various bands are discussed in the framework of Principal/Tilted Axis Cranking (PAC/TAC) model and the deformed Hartree-Fock and angular momentum projection (PHF) calculations. Level energies and B(M1)/B(E2) ratios have, on the whole, been reproduced for the assigned configurations. Triaxial deformation in these mass regions has been inferred from the observed rotational-alignment frequencies, staggering behavior, M1 reduced transition probabilities and chiral-twin bands. Another important feature observed in these isotopes is the magnetic dipole bands generated through the shears mechanism. Observation of new E1 transitions linking the opposite-parity bands based on the proton/neutron h 11/2 and d 5/2 orbitals (Δl = 3, Δj = 1, Δπ = -1) in 131 Cs and 99 Pd provide fingerprints of possible octupole correlations in these mass-regions. (author)

''Identical'' bands in normally-deformed nuclei

International Nuclear Information System (INIS)

Garrett, J.D.; Baktash, C.; Yu, C.H.

1990-01-01

Gamma-ray transitions energies in neighboring odd- and even-mass nuclei for normally-deformed nuclear configurations are analyzed in a manner similar to recent analyses for superdeformed states. The moment of inertia is shown to depend on pair correlations and the aligned angular momentum of the odd nucleon. The implications of this analysis for ''identical'' super-deformed bands are discussed. 26 refs., 9 figs

Influence of hexadecapole deformations of the nuclear shape of subbarrier fusion reactions

International Nuclear Information System (INIS)

Fernandez Niello, J.

1989-01-01

A systematic study of the contribution of hexadecapole deformations to the enhancement of subbarrier fusion cross reactions is carried out. The analysis is based on calculations that cover the full range of values of hexadecapole deformations found in actual nuclear systems. The interplay of this shape degree of freedom with the presence of prolate quadrupole deformations is also contemplated. (Author) [es

Solid-Gas Coupling Model for Coal-Rock Mass Deformation and Pressure Relief Gas Flow in Protection Layer Mining

OpenAIRE

Zhu, Zhuohui; Feng, Tao; Yuan, Zhigang; Xie, Donghai; Chen, Wei

2018-01-01

The solid-gas coupling model for mining coal-rock mass deformation and pressure relief gas flow in protection layer mining is the key to determine deformation of coal-rock mass and migration law of pressure relief gas of protection layer mining in outburst coal seams. Based on the physical coupling process between coal-rock mass deformation and pressure-relief gas migration, the coupling variable of mining coal-rock mass, a part of governing equations of gas seepage field and deformation fiel...

Barriers in the energy of deformed nuclei

Directory of Open Access Journals (Sweden)

V. Yu. Denisov

2014-06-01

Full Text Available Interaction energy between two nuclei considering to their deformations is studied. Coulomb and nuclear in-teraction energies, as well as the deformation energies of both nuclei, are taken into account at evaluation of the interaction energy. It is shown that the barrier related to the interaction energy of two nuclei depends on the de-formations and the height of the minimal barrier is evaluated. It is obtained that the heavier nucleus-nucleus sys-tems have large deformation values at the lowest barrier. The difference between the barrier between spherical nuclei and the lowest barrier between deformed nuclei increases with the mass and the charge of the interacting nuclei.

Nuclear-deformation energies according to a liquid-drop model with a sharp surface

International Nuclear Information System (INIS)

Blocki, J.; Swiatecki, W.J.

1982-05-01

We present an atlas of 665 deformation-energy maps and 150 maps of other properties of interest, relevant for nuclear systems idealized as uniformly charged drops endowed with a surface tension. The nuclear shapes are parametrized in terms of two spheres modified by a smoothly fitted quadratic surface of revolution and are specified by three variables: asymmetry, sphere separation, and a neck variable (that goes over into a fragment-deformation variable after scission). The maps and related tables should be useful for the study of macroscopic aspects of nuclear fission and of collisions between any two nuclei in the periodic table

Mass deformations of 5d SCFTs via holography

Science.gov (United States)

Gutperle, Michael; Kaidi, Justin; Raj, Himanshu

2018-02-01

Using six-dimensional Euclidean F (4) gauged supergravity we construct a holographic renormalization group flow for a CFT on S 5. Numerical solutions to the BPS equations are obtained and the free energy of the theory on S 5 is determined holographically by calculation of the renormalized on-shell supergravity action. In the process, we deal with subtle issues such as holographic renormalization and addition of finite counterterms. We then propose a candidate field theory dual to these solutions. This tentative dual is a supersymmetry-preserving deformation of the strongly-coupled non-Lagrangian SCFT derived from the D4-D8 system in string theory. In the IR, this theory is a mass deformation of a USp(2 N ) gauge theory. A localization calculation of the free energy is performed for this IR theory, which for reasonably small values of the deformation parameter is found to have the same qualitative behaviour as the holographic free energy.

Nuclear limits on gravitational waves from elliptically deformed pulsars

International Nuclear Information System (INIS)

Krastev, Plamen G.; Li Baoan; Worley, Aaron

2008-01-01

Gravitational radiation is a fundamental prediction of General Relativity. Elliptically deformed pulsars are among the possible sources emitting gravitational waves (GWs) with a strain-amplitude dependent upon the star's quadrupole moment, rotational frequency, and distance from the detector. We show that the gravitational wave strain amplitude h 0 depends strongly on the equation of state of neutron-rich stellar matter. Applying an equation of state with symmetry energy constrained by recent nuclear laboratory data, we set an upper limit on the strain-amplitude of GWs produced by elliptically deformed pulsars. Depending on details of the EOS, for several millisecond pulsars at distances 0.18 kpc to 0.35 kpc from Earth, the maximalh 0 is found to be in the range of ∼[0.4-1.5]x10 -24 . This prediction serves as the first direct nuclear constraint on the gravitational radiation. Its implications are discussed

Nuclear structure at high-spin and large-deformation

International Nuclear Information System (INIS)

Shimizu, Yoshifumi R.

2000-01-01

Atomic nucleus is a finite quantal system and shows various marvelous features. One of the purposes of the nuclear structure study is to understand such features from a microscopic viewpoint of nuclear many-body problem. Recently, it is becoming possible to explore nuclear states under 'extreme conditions', which are far different from the usual ground states of stable nuclei, and new aspects of such unstable nuclei attract our interests. In this lecture, I would like to discuss the nuclear structure in the limit of rapid rotation, or the extreme states with very large angular momenta, which became accessible by recent advent of large arrays of gamma-ray detecting system; these devices are extremely useful to measure coincident multiple γ-rays following heavy-ion fusion reactions. Including such experimental aspects as how to detect the nuclear rotational states, I review physics of high-spin states starting from the elementary subjects of nuclear structure study. In would like also to discuss the extreme states with very large nuclear deformation, which are easily realized in rapidly rotating nuclei. (author)

Observation of Compressive Deformation Behavior of Nuclear Graphite by Digital Image Correlation

International Nuclear Information System (INIS)

Kim, Hyunju; Kim, Eungseon; Kim, Minhwan; Kim, Yongwan

2014-01-01

Polycrystalline nuclear graphite has been proposed as a fuel element, moderator and reflector blocks, and core support structures in a very high temperature gas-cooled reactor. During reactor operation, graphite core components and core support structures are subjected to various stresses. It is therefore important to understand the mechanism of deformation and fracture of nuclear graphites, and their significance to structural integrity assessment methods. Digital image correlation (DIC) is a powerful tool to measure the full field displacement distribution on the surface of the specimens. In this study, to gain an understanding of compressive deformation characteristic, the formation of strain field during a compression test was examined using a commercial DIC system. An examination was made to characterize the compressive deformation behavior of nuclear graphite by a digital image correlation. The non-linear load-displacement characteristic prior to the peak load was shown to be mainly dominated by the presence of localized strains, which resulted in a permanent displacement. Young's modulus was properly calculated from the measured strain

Nuclear quantum shape-phase transitions in odd-mass systems

Science.gov (United States)

Quan, S.; Li, Z. P.; Vretenar, D.; Meng, J.

2018-03-01

Microscopic signatures of nuclear ground-state shape-phase transitions in odd-mass Eu isotopes are explored starting from excitation spectra and collective wave functions obtained by diagonalization of a core-quasiparticle coupling Hamiltonian based on energy density functionals. As functions of the physical control parameter—the number of nucleons—theoretical low-energy spectra, two-neutron separation energies, charge isotope shifts, spectroscopic quadrupole moments, and E 2 reduced transition matrix elements accurately reproduce available data and exhibit more-pronounced discontinuities at neutron number N =90 compared with the adjacent even-even Sm and Gd isotopes. The enhancement of the first-order quantum phase transition in odd-mass systems can be attributed to a shape polarization effect of the unpaired proton which, at the critical neutron number, starts predominantly coupling to Gd core nuclei that are characterized by larger quadrupole deformation and weaker proton pairing correlations compared with the corresponding Sm isotopes.

Nuclear deformation and expression change of cartilaginous genes during in vitro expansion of chondrocytes

International Nuclear Information System (INIS)

Hoshiba, Takashi; Yamada, Tomoe; Lu, Hongxu; Kawazoe, Naoki; Tateishi, Tetsuya; Chen, Guoping

2008-01-01

Cartilaginous gene expression decreased when chondrocytes were expanded on cell-culture plates. Understanding the dedifferentiation mechanism may provide valuable insight into cartilage tissue engineering. Here, we demonstrated the relationship between the nuclear shape and gene expression during in vitro expansion culture of chondrocytes. Specifically, the projected nuclear area increased and cartilaginous gene expressions decreased during in vitro expansion culture. When the nuclear deformation was recovered by cytochalasin D treatment, aggrecan expression was up-regulated and type I collagen (Col1a2) expression was down-regulated. These results suggest that nuclear deformation may be one of the mechanisms for chondrocyte dedifferentiation during in vitro expansion culture

In situ nuclear magnetic resonance study of defect dynamics during deformation of materials

NARCIS (Netherlands)

Murty, K.L.; Detemple, K.; Kanert, O.; Peters, G; de Hosson, J.T.M.

1996-01-01

Nuclear magnetic resonance techniques can be used to monitor in situ the dynamical behaviour of point and line defects in materials during deformation. These techniques are non-destructive and non-invasive. We report here the atomic transport, in particular the enhanced diffusion during deformation

Low-mass neutron stars: universal relations, the nuclear symmetry energy and gravitational radiation

Science.gov (United States)

O. Silva, Hector; Berti, Emanuele; Sotani, Hajime

2016-03-01

Compact objects such as neutron stars are ideal astrophysical laboratories to test our understanding of the fundamental interactions in the regime of supranuclear densities, unachievable by terrestrial experiments. Despite recent progress, the description of matter (i.e., the equation of state) at such densities is still debatable. This translates into uncertainties in the bulk properties of neutron stars, masses and radii for instance. Here we will consider low-mass neutron stars. Such stars are expected to carry important information on nuclear matter near the nuclear saturation point. It has recently been shown that the masses and surface redshifts of low-mass neutron stars smoothly depend on simple functions of the central density and of a characteristic parameter η associated with the choice of equation of state. Here we extend these results to slowly-rotating and tidally deformed stars and obtain empirical relations for various quantities, such as the moment of inertia, quadrupole moment and ellipticity, tidal and rotational Love numbers, and rotational apsidal constants. We discuss how these relations might be used to constrain the equation of state by future observations in the electromagnetic and gravitational-wave spectra.

The art of predicting nuclear masses

International Nuclear Information System (INIS)

Hirsch, J.G.; Morales, I.; Mendoza-Temis, J.; Frank, A.; Lopez-Vieyra, J.C.; Barea, J.; Pittel, S.; Van Isacker, P.; Velazquez, V.

2008-01-01

A review of recent advances in the theoretical analysis of nuclear mass models and their predictive power is presented. After introducing two tests which probe the ability of nuclear mass models to extrapolate, three models are analyzed in detail: the liquid drop model (LDM), the liquid drop model plus empirical shell corrections (LDMM) and the Duflo–Zuker mass formula (DZ). The DZ model is exhibited as the most predictive model. The Garvey–Kelson mass relations are also discussed. It is shown that their fulfillment probes the consistency of the most commonly used mass formulae, and that they can be used in an iterative process to predict nuclear masses in the neighborhood of nuclei with measured masses, offering a simple and reproducible procedure for short range mass predictions. (author)

Underlying physics of identical odd- and even-mass bands in normally deformed rare-earth nuclei

International Nuclear Information System (INIS)

Yu Lei; Liu Shuxin; Lei Yian; Zeng Jinyan

2001-01-01

The microscopic mechanism of the identical odd- and even-mass number nuclear bands in normally deformed rare-earth nuclei was investigated using the particle-number conserving (PNC) method for treating nuclear pairing correlation. It was found that the odd particle of an odd-A identical band always occupied a cranked low j and high Ω Nilsson orbital (e.g. proton [404]7/2, [402]5/2. On the contrary, if the odd particle occupies an intruder high j orbital (e.g. neutron [633]7/2, proton[514]9/2), the moment of inertia of the odd-A band was much larger than that of neighboring even-even ground state band. The observed variation of moment of inertia (below band crossing) was reproduced quite well by the PNC calculation, in which no free parameter was involved. The strengths of monopole and Y 20 quadrupole interactions were determined by the experimental odd-even differences in binding energy and band head moment of inertia

Thomas-Fermi treatment of nuclear masses, deformations and density distributions

International Nuclear Information System (INIS)

Myers, W.D.; Swiatecki, W.J.

1994-08-01

A recently completed Thomas-Fermi model of nuclei is described. Six adjustable parameters of the effective nucleon-nucleon interaction were fitted to the shell-corrected binding energies of 1654 nuclei and to the diffuseness of the nuclear surface. The model is then successful in reproducing nuclear sizes, and only small deviations are found between calculated and measured fission barriers of 36 nuclei. The model is applied to the prediction of fission barriers of light elements, to drip-line nuclei like 82 Sn and 170 Sn, to the properties of nuclear and neutron matter and to nuclear bubble configurations with Z 2 /A ∼ 100. The relation of a Thomas-Fermi theory to the Droplet and Liquid Drop models is illustrated

Penning-trap mass spectrometry and mean-field study of nuclear shape coexistence in the neutron-deficient lead region

Science.gov (United States)

Manea, V.; Ascher, P.; Atanasov, D.; Barzakh, A. E.; Beck, D.; Blaum, K.; Borgmann, Ch.; Breitenfeldt, M.; Cakirli, R. B.; Cocolios, T. E.; Day Goodacre, T.; Fedorov, D. V.; Fedosseev, V. N.; George, S.; Herfurth, F.; Kowalska, M.; Kreim, S.; Litvinov, Yu. A.; Lunney, D.; Marsh, B.; Neidherr, D.; Rosenbusch, M.; Rossel, R. E.; Rothe, S.; Schweikhard, L.; Wienholtz, F.; Wolf, R. N.; Zuber, K.

2017-05-01

We present a study of nuclear shape coexistence in the region of neutron-deficient lead isotopes. The midshell gold isotopes 180,185,188,190Au (Z =79 ), the two long-lived nuclear states in 197At (Z =85 ), and the neutron-rich nuclide 219At were produced by the ISOLDE facility at CERN and their masses were determined with the high-precision Penning-trap mass spectrometer ISOLTRAP. The studied gold isotopes address the trend of binding energies in a region of the nuclear chart where the nuclear charge radii show pronounced discontinuities. Significant deviations from the atomic-mass evaluation were found for Au,190188. The new trend of two-neutron separation energies is smoother, although it does reveal the onset of deformation. The origin of this effect is interpreted in connection to the odd-even staggering of binding energies, as well as theoretically by Hartree-Fock-Bogoliubov calculations including quasiparticle blocking. The role of blocking for reproducing the large odd-even staggering of charge radii in the mercury isotopic chain is illustrated.

Critical assessment of nuclear mass models

International Nuclear Information System (INIS)

Moeller, P.; Nix, J.R.

1992-01-01

Some of the physical assumptions underlying various nuclear mass models are discussed. The ability of different mass models to predict new masses that were not taken into account when the models were formulated and their parameters determined is analyzed. The models are also compared with respect to their ability to describe nuclear-structure properties in general. The analysis suggests future directions for mass-model development

Imprints of the nuclear symmetry energy on gravitational waves from deformed pulsars

International Nuclear Information System (INIS)

Li, Baoan; Krastev, P.G.

2010-01-01

The density dependence of nuclear symmetry energy is a critical input for understanding many interesting phenomena in astrophysics and cosmology. We report here effects of the nuclear symmetry energy partially constrained by terrestrial laboratory experiments on the strength of gravitational waves (GWs) from deformed pulsars at both low and high rotational frequencies. (author)

Mass Spectrometric Analysis for Nuclear Safeguards

International Nuclear Information System (INIS)

Boulyga, S.

2013-01-01

The release of man-made radionuclides into the environment results in contamination that carries specific isotopic signatures according to the release scenarios and the previous usage of materials and facilities. In order to trace the origin of such contamination and/or to assess the potential impact on the public and environmental health, it is necessary to determine the isotopic composition and activity concentrations of radionuclides in environmental samples in an accurate and timely fashion. Mass spectrometric techniques, such as thermal ionization mass spectrometry (TIMS), secondary ion mass spectrometry (SIMS), and inductively coupled plasma mass spectrometry (ICP-MS) belong to the most powerful methods for analysis of nuclear and related samples in nuclear safeguards, forensics, and environmental monitoring. This presentation will address the potential of mass spectrometric analysis of actinides at ultra-trace concentration levels, isotopic analysis of micro-samples, age determination of nuclear materials as well as identification and quantification of elemental and isotopic signatures of nuclear samples in general. (author)

Shear Creep Simulation of Structural Plane of Rock Mass Based on Discontinuous Deformation Analysis

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Guoxin Zhang

2017-01-01

Full Text Available Numerical simulations of the creep characteristics of the structural plane of rock mass are very useful. However, most existing simulation methods are based on continuum mechanics and hence are unsuitable in the case of large displacements and deformations. The discontinuous deformation analysis method proposed by Genhua is a discrete one and has a significant advantage when simulating the contacting problem of blocks. In this study, we combined the viscoelastic rheological model of Burgers with the discontinuous deformation analysis (DDA method. We also derived the recurrence formula for the creep deformation increment with the time step during numerical simulations. Based on the minimum potential energy principle, the general equilibrium equation was derived, and the shear creep deformation in the structural plane was considered. A numerical program was also developed and its effectiveness was confirmed based on the curves obtained by the creep test of the structural plane of a rock mass under different stress levels. Finally, the program was used to analyze the mechanism responsible for the creep features of the structural plane in the case of the toppling deformation of the rock slope. The results showed that the extended DDA method is an effective one.

Observations of borehole deformation modulus values before and after extensive heating of a granitic rock mass

International Nuclear Information System (INIS)

Patrick, W.C.; Yow, J.L.; Caxelrod, M.C.

1985-01-01

An extensive campaign of in situ deformation modulus measurements was recently completed using a standard NX borehole jack. These results were obtained in a granite intrusive where spent nuclear-fuel assemblies and electrical heaters had raised the rock temperatures 10 0 C to 40 0 C above ambient. We present an analysis of temperature effects based on 41 preheat and 63 post-heat measurements in three boreholes. Using analysis of covariance statistical techniques, we found that the deformation modulus is affected by heat, loading direction, and position within the borehole. The analysis also uncovered a significant interaction between the effects of heating and loading direction. We used 123 measurements from the same boreholes to evaluate the ''Draft Standard Guide for Estimating the In Situ Modulus of Rock Masses Using the NX-Borehole Jack'' which was recently proposed by Heuze. In particular, we examined the criterion for screening measurements in those cases where contact between the jack platen and the borehole wall was incomplete. We found that the proposed screen appears to operate randomly on the data and is therefore ineffective

Quantum chaos and nuclear mass systematics

International Nuclear Information System (INIS)

Hirsch, Jorge G.; Velazquez, Victor; Frank, Alejandro

2004-01-01

The presence of quantum chaos in nuclear mass systematics is analyzed by considering the differences between measured and calculated nuclear masses as a time series described by the power law 1fα. While for the liquid droplet model plus shell corrections a quantum chaotic behavior α∼1 is found, errors in the microscopic mass formula have α∼0.5, closer to white noise. The chaotic behavior seems to arise from many body effects not included in the mass formula

A systematic study of even-even nuclei in the nuclear chart by the relativistic mean field theory

Energy Technology Data Exchange (ETDEWEB)

Sumiyoshi, K.; Hirata, D.; Tanihata, I.; Sugahara, Y.; Toki, H. [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

1997-03-01

We study systematically the properties of nuclei in the whole mass range up to the drip lines by the relativistic mean field (RMF) theory with deformations as a microscopic framework to provide the data of nuclear structure in the nuclear chart. The RMF theory is a phenomenological many-body framework, in which the self-consistent equations for nucleons and mesons are solved with arbitrary deformation, and has a potential ability to provide all the essential information of nuclear structure such as masses, radii and deformations together with single particle states and wave functions from the effective lagrangian containing nuclear interaction. As a first step toward the whole project, we study the ground state properties of even-even nuclei ranging from Z=8 to Z=120 up to the proton and neutron drip lines in the RMF theory. We adopt the parameter set TMA, which has been determined by the experimental masses and charge radii in a wide mass range, for the effective lagrangian of the RMF theory. We take into account the axially symmetric deformation using the constrained method on the quadrupole moment. We provide the properties of all even-even nuclei with all the possible ground state deformations extracted from the deformation energy curves by the constrained calculations. By studying the calculated ground state properties systematically, we aim to explore the general trend of masses, radii and deformations in the whole region of the nuclear chart. We discuss the agreement with experimental data and the predictions such as magicness and triaxial deformations beyond the experimental frontier. (author)

Use of multiscale zirconium alloy deformation models in nuclear fuel behavior analysis

Energy Technology Data Exchange (ETDEWEB)

Montgomery, Robert, E-mail: robert.montgomery@pnnl.gov [Pacific Northwest National Laboratory (United States); Tomé, Carlos, E-mail: tome@lanl.gov [Los Alamos National Laboratory (United States); Liu, Wenfeng, E-mail: wenfeng.liu@anatech.com [ANATECH Corporation (United States); Alankar, Alankar, E-mail: alankar.alankar@iitb.ac.in [Indian Institute of Technology Bombay (India); Subramanian, Gopinath, E-mail: gopinath.subramanian@usm.edu [University of Southern Mississippi (United States); Stanek, Christopher, E-mail: stanek@lanl.gov [Los Alamos National Laboratory (United States)

2017-01-01

Accurate prediction of cladding mechanical behavior is a key aspect of modeling nuclear fuel behavior, especially for conditions of pellet-cladding interaction (PCI), reactivity-initiated accidents (RIA), and loss of coolant accidents (LOCA). Current approaches to fuel performance modeling rely on empirical constitutive models for cladding creep, growth and plastic deformation, which are limited to the materials and conditions for which the models were developed. To improve upon this approach, a microstructurally-based zirconium alloy mechanical deformation analysis capability is being developed within the United States Department of Energy Consortium for Advanced Simulation of Light Water Reactors (CASL). Specifically, the viscoplastic self-consistent (VPSC) polycrystal plasticity modeling approach, developed by Lebensohn and Tomé [1], has been coupled with the BISON engineering scale fuel performance code to represent the mechanistic material processes controlling the deformation behavior of light water reactor (LWR) cladding. A critical component of VPSC is the representation of the crystallographic nature (defect and dislocation movement) and orientation of the grains within the matrix material and the ability to account for the role of texture on deformation. A future goal is for VPSC to obtain information on reaction rate kinetics from atomistic calculations to inform the defect and dislocation behavior models described in VPSC. The multiscale modeling of cladding deformation mechanisms allowed by VPSC far exceed the functionality of typical semi-empirical constitutive models employed in nuclear fuel behavior codes to model irradiation growth and creep, thermal creep, or plasticity. This paper describes the implementation of an interface between VPSC and BISON and provides initial results utilizing the coupled functionality.

$J/\\Psi$ mass shift in nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Gastao Krein, Anthony Thomas, Kazuo Tsushima

2011-02-01

The $J/\\Psi$ mass shift in cold nuclear matter is computed using an effective Lagrangian approach. The mass shift is computed by evaluating $D$ and $D^*$ meson loop contributions to the $J/\\Psi$ self-energy employing medium-modified meson masses. The modification of the $D$ and $D^*$ masses in nuclear matter is obtained using the quark-meson coupling model. The loop integrals are regularized with dipole form factors and the sensitivity of the results to the values of form-factor cutoff masses is investigated. The $J/\\Psi$ mass shift arising from the modification of the $D$ and $D^*$ loops at normal nuclear matter density is found to range from $-16$~MeV to $-24$~MeV under a wide variation of values of the cutoff masses. Experimental perspectives for the formation of a bound state of $J/\\Psi$ to a nucleus are investigated.

Deformation inside and outside the nuclear molecules

International Nuclear Information System (INIS)

Cseh, J.; Algora, A.; Antonenko, N.V.; Jolos, R.V.; Hess, P.O.

2006-01-01

Complete text of publication follows. Clusterization is an important phenomenon both in light and in heavy nuclei. The two basic natural laws governing the clusterization (just like the composition of nuclei from nucleons) are the energy-minimum principle, and the Pauli-exclusion principle. In a fully microscopic description of clusterization both aspects are taken into account. This kind of description, however, is limited to the territory of light nuclei. Many interesting aspects of the clusterization, like e.g. the appearance of exotic cluster configurations, show up only in heavy nuclei. Phenomenologic approaches are applied both to light and to heavy nuclei, on an equal footing, but these models do not really contain the effects of the antisymmetrization, or it is not under control, what aspects of the exclusion principle is incorporated. Recently we have developed an approach, which involves both the energetic preference and the exclusion principle [?]. The antisymmetrization is not carried out explicitly, it is treated in an approximate way, but it is done microscopically in a well-controlled manner, and consistency-check measures, how effective it is. We calculate the energetic preference of different clusterizations both on the basis of simple binding-energy-arguments [?], and from the Dinuclear System Model (DNS) [?], including Coulomb as well as nuclear interactions. The potential energy is calculated both for the usual pole-to-pole configuration, and for those more compact configurations, which turn out to be allowed from the microscopic viewpoint. The exclusion principle is treated by the application of a selection rule, related to the microscopic structure. For light nuclei it is based on the real U(3) symmetry [?], and it is exact to the extent to which the leading term representation is valid. In heavy nuclei it is based on the quasidynamical, or effective U(3) symmetry [?]. Its validity is shown by the consistency of the quadrupole deformation of

Plasma Mass Filters For Nuclear Waste Reprocessing

International Nuclear Information System (INIS)

Fetterman, Abraham J.; Fisch, Nathaniel J.

2011-01-01

Practical disposal of nuclear waste requires high-throughput separation techniques. The most dangerous part of nuclear waste is the fission product, which contains the most active and mobile radioisotopes and produces most of the heat. We suggest that the fission products could be separated as a group from nuclear waste using plasma mass filters. Plasmabased processes are well suited to separating nuclear waste, because mass rather than chemical properties are used for separation. A single plasma stage can replace several stages of chemical separation, producing separate streams of bulk elements, fission products, and actinoids. The plasma mass filters may have lower cost and produce less auxiliary waste than chemical processing plants. Three rotating plasma configurations are considered that act as mass filters: the plasma centrifuge, the Ohkawa filter, and the asymmetric centrifugal trap.

Seasonal Mass Changes and Crustal Vertical Deformations Constrained by GPS and GRACE in Northeastern Tibet

Directory of Open Access Journals (Sweden)

Yuanjin Pan

2016-08-01

Full Text Available Surface vertical deformation includes the Earth’s elastic response to mass loading on or near the surface. Continuous Global Positioning System (CGPS stations record such deformations to estimate seasonal and secular mass changes. We used 41 CGPS stations to construct a time series of coordinate changes, which are decomposed by empirical orthogonal functions (EOFs, in northeastern Tibet. The first common mode shows clear seasonal changes, indicating seasonal surface mass re-distribution around northeastern Tibet. The GPS-derived result is then assessed in terms of the mass changes observed in northeastern Tibet. The GPS-derived common mode vertical change and the stacked Gravity Recovery and Climate Experiment (GRACE mass change are consistent, suggesting that the seasonal surface mass variation is caused by changes in the hydrological, atmospheric and non-tidal ocean loads. The annual peak-to-peak surface mass changes derived from GPS and GRACE results show seasonal oscillations in mass loads, and the corresponding amplitudes are between 3 and 35 mm/year. There is an apparent gradually increasing gravity between 0.1 and 0.9 μGal/year in northeast Tibet. Crustal vertical deformation is determined after eliminating the surface load effects from GRACE, without considering Glacial Isostatic Adjustment (GIA contribution. It reveals crustal uplift around northeastern Tibet from the corrected GPS vertical velocity. The unusual uplift of the Longmen Shan fault indicates tectonically sophisticated processes in northeastern Tibet.

Systematics of triaxial moment of inertia and deformation parameters (β, γ) in even-even nuclei of mass region A = 90-120

International Nuclear Information System (INIS)

Singh, Yuvraj; Gupta, D.K.; Singh, M.; Gupta, K.K.; Bihari, Chhail; Varshney, A.K.; Dhiman, S.K.

2012-01-01

The deformation parameter β and γ of the collective model of Bohr and Mottelson are basic descriptors of the nuclear equilibrium shape and structure. In recent past the sets of deformation parameters ((β, γ) have been extracted from both level energies and E2 transition rates in even Xe, Ba and Ce nuclei (A∼120-140) and Hf, W, Os, Pt and Hg nuclei (A∼160-200) using rigid triaxial rotor model of Davydov-Filippov (DF). Researcher have found that the values of β obtained separately from energy and transition rate (β e and β b respectively), though, are found almost equal in heavy mass region (A ∼160-200) but, not so in medium mass (A∼120-140) nuclei. This observation puts a question mark whether the ββ dependence of moment of inertia in hydrodynamic model is reliable. The purpose of the present work is to study a relatively lighter mass region (A∼90-120) where the gap between values of two sets of β may further increase. To improve the calculations for extracting β e , the use of Grodzins rule will be made along with uncertainties, since only through this rule the E2 1 + is related with β G (value of β for symmetric nucleus and evaluated using Grodzins rule)

Modelling heat and mass transfer in bread baking with mechanical deformation

International Nuclear Information System (INIS)

Nicolas, V; Glouannec, P; Ploteau, J-P; Salagnac, P; Jury, V; Boillereaux, L

2012-01-01

In this paper, the thermo-hydric behaviour of bread during baking is studied. A numerical model has been developed with Comsol Multiphysics© software. The model takes into account the heat and mass transfers in the bread and the phenomenon of swelling. This model predicts the evolution of temperature, moisture, gas pressure and deformation in French 'baguette' during baking. Local deformation is included in equations using solid phase conservation and, global deformation is calculated using a viscous mechanic model. Boundary conditions are specified with the sole temperature model and vapour pressure estimation of the oven during baking. The model results are compared with experimental data for a classic baking. Then, the model is analysed according to physical properties of bread and solicitations for a better understanding of the interactions between different mechanisms within the porous matrix.

Bifurcations and chaos of classical trajectories in a deformed nuclear potential

International Nuclear Information System (INIS)

Carbonell, J.; Arvieu, R.

1982-10-01

The purpose is to describe the general organization of the trajectories of a nucleon in a deformed potential both in phase space and in configuration space. This question gives rise to a very complex problem in a deformed potential. There one is in the frame of the theory of nonintegrable systems. Many very important mathematical theorems (like K.A.M. theorem) are needed as well as any results of bifurcation theory and also of numerical experiments. This work belongs entirely to classical mechanics. The main problems to be treated are: the organization of phase space, the connection with simple known limiting cases and bifurcation theory, and the occurrence of chaotic trajectories in a nuclear field. These problems must be solved as functions of the size, the deformation of the potential and the excitation energy of the particle

Bifurcations and chaos of classical trajectories in a deformed nuclear potential

Energy Technology Data Exchange (ETDEWEB)

Carbonell, J; Arvieu, R

1982-10-01

The purpose is to describe the general organization of the trajectories of a nucleon in a deformed potential both in phase space and in configuration space. This question gives rise to a very complex problem in a deformed potential. There one is in the frame of the theory of nonintegrable systems. Many very important mathematical theorems (like K.A.M. theorem) are needed as well as any results of bifurcation theory and also of numerical experiments. This work belongs entirely to classical mechanics. The main problems to be treated are: the organization of phase space, the connection with simple known limiting cases and bifurcation theory, and the occurrence of chaotic trajectories in a nuclear field. These problems must be solved as functions of the size, the deformation of the potential and the excitation energy of the particle.

Global nuclear-structure calculations

International Nuclear Information System (INIS)

Moeller, P.; Nix, J.R.

1990-01-01

The revival of interest in nuclear ground-state octupole deformations that occurred in the 1980's was stimulated by observations in 1980 of particularly large deviations between calculated and experimental masses in the Ra region, in a global calculation of nuclear ground-state masses. By minimizing the total potential energy with respect to octupole shape degrees of freedom in addition to ε 2 and ε 4 used originally, a vastly improved agreement between calculated and experimental masses was obtained. To study the global behavior and interrelationships between other nuclear properties, we calculate nuclear ground-state masses, spins, pairing gaps and Β-decay and half-lives and compare the results to experimental qualities. The calculations are based on the macroscopic-microscopic approach, with the microscopic contributions calculated in a folded-Yukawa single-particle potential

Precision Mass Measurements of Cr-6358 : Nuclear Collectivity Towards the N =40 Island of Inversion

Science.gov (United States)

Mougeot, M.; Atanasov, D.; Blaum, K.; Chrysalidis, K.; Goodacre, T. Day; Fedorov, D.; Fedosseev, V.; George, S.; Herfurth, F.; Holt, J. D.; Lunney, D.; Manea, V.; Marsh, B.; Neidherr, D.; Rosenbusch, M.; Rothe, S.; Schweikhard, L.; Schwenk, A.; Seiffert, C.; Simonis, J.; Stroberg, S. R.; Welker, A.; Wienholtz, F.; Wolf, R. N.; Zuber, K.

2018-06-01

The neutron-rich isotopes Cr 58 - 63 were produced for the first time at the ISOLDE facility and their masses were measured with the ISOLTRAP spectrometer. The new values are up to 300 times more precise than those in the literature and indicate significantly different nuclear structure from the new mass-surface trend. A gradual onset of deformation is found in this proton and neutron midshell region, which is a gateway to the second island of inversion around N =40 . In addition to comparisons with density-functional theory and large-scale shell-model calculations, we present predictions from the valence-space formulation of the ab initio in-medium similarity renormalization group, the first such results for open-shell chromium isotopes.

Mass spectrometry in nuclear science and technology

International Nuclear Information System (INIS)

Komori, Takuji

1985-01-01

Mass spectrometry has been widely used and playing a very important role in the field of nuclear science and technology. A major reason for this is that not only the types of element but also its isotopes have to be identified and measured in this field. Thus, some applications of this analytical method are reviewed and discussed in this article. Its application to analytical chemistry is described in the second section following an introductory section, which includes subsections for isotropic dilution mass spectrometry, resonance ionization mass spectrometry and isotopic correlation technique. The isotopic ratio measurement for hydrogen, uranium and plutonium as well as nuclear material control and safeguards are also reviewed in this section. In the third section, mass spectrometry is discussed in relation to nuclear reactors, with subsections on natural uranium reactor and neutron flux observation. Some techniques for measuring the burnup fraction, including the heavy isotopic ratio method and fission product monitoring, are also described. In the fourth section, application of mass spectrometry to measurement of nuclear constants, such as ratio of effective cross-sectional area for 235 U, half-life and fission yield is reviewed. (Nogami, K.)

CHANGE IN DEFORMATION PROPERTIES MODELING OF CONCRETE IN PROTECTIVE STRUCTURES OF NUCLEAR REACTOR BY IONIZING RADIATION

Directory of Open Access Journals (Sweden)

E. K. Agakhanov

2016-01-01

Full Text Available The necessity of studying the effect impact of elementary particles impact on the strength and deformation materials properties used in protective constructions nuclear reactors and reactor technology has been stipulated. A nuclear reactor pressure vessel from prestressed concrete, combining the functions of biological protection is to be considered. The neutron flux problem distribution in the pressure vessel of a nuclear reactor has been solved. The solution is made in axisymmetric with the finite element method using a flat triangular finite element. Computing has been conducted in Matlab package. The comparison with the results has been obtained using the finite difference method, as well as the graphs of changes under the influence of radiation exposure and the elastic modulus of concrete radiation deformations have been constructed. The proposed method allows to simulate changes in the deformation properties of concrete under the influence of neutron irradiation. Results of the study can be used in the calculation of stress-strain state of structures, taking into account indirect heterogeneity caused by the physical fields influence.

The Gogny-Hartree-Fock-Bogoliubov nuclear-mass model

Energy Technology Data Exchange (ETDEWEB)

Goriely, S. [Universite Libre de Bruxelles, Institut d' Astronomie et d' Astrophysique, CP-226, Brussels (Belgium); Hilaire, S.; Girod, M.; Peru, S. [CEA, DAM, DIF, Arpajon (France)

2016-07-15

We present the Gogny-Hartree-Fock-Bogoliubov model which reproduces nuclear masses with an accuracy comparable with the best mass formulas. In contrast to the Skyrme-HFB nuclear-mass models, an explicit and self-consistent account of all the quadrupole correlation energies is included within the 5D collective Hamiltonian approach. The final rms deviation with respect to the 2353 measured masses is 789 keV in the 2012 atomic mass evaluation. In addition, the D1M Gogny force is shown to predict nuclear and neutron matter properties in agreement with microscopic calculations based on realistic two- and three-body forces. The D1M properties and its predictions of various observables are compared with those of D1S and D1N. (orig.)

STRESSES AND DEFORMABILITY OF ROCK MASS UPON OPEN PIT EXPLOITATION OF DIMENSION STONE

Directory of Open Access Journals (Sweden)

Siniša Dunda

2003-12-01

Full Text Available The appearance of increased stresses and deformability of rock mass in the quarry of Zečevo (exploitation field of Selca – island of Brač has caused a considerable decrease of usability of mineral raw materials, which put into question the survival of the pit. Therefore the research and measurements of the state of stresses and deformability of rock mass within the pit were carried out. Besides detailed laboratory testings (testings on small samples performed were trial in-situ testings on large samples including the corresponding numerical analyses. The exploitation of dimension stone by sowing regularly shaped rectangular blocks has been proved to be appropriate for in-situ testing of bending strength. The paper presents the results of carried out laboratory testings, in-situ testings of bending strength including measuring of deformations after sowing cuts and numerical analyses by which the possible range of horizontal stresses was determined. Since for the case of massive rocks, for which the continuum concept is applied, there are no specifically defined methods of corrections, presented is a possible relation for correction of input size values based on the carried out laboratory and in-situ testings.

Effect of deformation and orientation on spin orbit density dependent nuclear potential

Science.gov (United States)

Mittal, Rajni; Kumar, Raj; Sharma, Manoj K.

2017-11-01

Role of deformation and orientation is investigated on spin-orbit density dependent part VJ of nuclear potential (VN=VP+VJ) obtained within semi-classical Thomas Fermi approach of Skyrme energy density formalism. Calculations are performed for 24-54Si+30Si reactions, with spherical target 30Si and projectiles 24-54Si having prolate and oblate shapes. The quadrupole deformation β2 is varying within range of 0.023 ≤ β2 ≤0.531 for prolate and -0.242 ≤ β2 ≤ -0.592 for oblate projectiles. The spin-orbit dependent potential gets influenced significantly with inclusion of deformation and orientation effect. The spin-orbit barrier and position gets significantly influenced by both the sign and magnitude of β2-deformation. Si-nuclei with β220. The possible role of spin-orbit potential on barrier characteristics such as barrier height, barrier curvature and on the fusion pocket is also probed. In reference to prolate and oblate systems, the angular dependence of spin-orbit potential is further studied on fusion cross-sections.

Empirical information on nuclear matter fourth-order symmetry energy from an extended nuclear mass formula

Directory of Open Access Journals (Sweden)

Rui Wang

2017-10-01

Full Text Available We establish a relation between the equation of state of nuclear matter and the fourth-order symmetry energy asym,4(A of finite nuclei in a semi-empirical nuclear mass formula by self-consistently considering the bulk, surface and Coulomb contributions to the nuclear mass. Such a relation allows us to extract information on nuclear matter fourth-order symmetry energy Esym,4(ρ0 at normal nuclear density ρ0 from analyzing nuclear mass data. Based on the recent precise extraction of asym,4(A via the double difference of the “experimental” symmetry energy extracted from nuclear masses, for the first time, we estimate a value of Esym,4(ρ0=20.0±4.6 MeV. Such a value of Esym,4(ρ0 is significantly larger than the predictions from mean-field models and thus suggests the importance of considering the effects of beyond the mean-field approximation in nuclear matter calculations.

Mass-deformed ABJM theory and LLM geometries: exact holography

Energy Technology Data Exchange (ETDEWEB)

Jang, Dongmin; Kim, Yoonbai; Kwon, O-Kab [Department of Physics, BK21 Physics Research Division,Institute of Basic Science, Sungkyunkwan University,Suwon 440-746 (Korea, Republic of); Tolla, D.D. [Department of Physics, BK21 Physics Research Division,Institute of Basic Science, Sungkyunkwan University,Suwon 440-746 (Korea, Republic of); University College, Sungkyunkwan University,Suwon 440-746 (Korea, Republic of)

2017-04-19

We present a detailed account and extension of our claim in https://arxiv.org/abs/1610.01490. We test the gauge/gravity duality between the N=6 mass-deformed ABJM theory with U{sub k}(N)×U{sub −k}(N) gauge symmetry and the 11-dimensional supergravity on LLM geometries with SO(4)/ℤ{sub k}×SO(4)/ℤ{sub k} isometry, in the large N limit. Our analysis is based on the evaluation of vacuum expectation values of chiral primary operators from the supersymmetric vacua of mass-deformed ABJM theory and from the implementation of Kaluza-Klein holography to the LLM geometries. We focus on the chiral primary operator with conformal dimension Δ=1. We show that 〈O{sup (Δ=1)}〉=N{sup (3/2)} f{sub (Δ=1)} for all supersymmetric vacuum solutions and LLM geometries with k=1, where the factor f{sub (Δ)} is independent of N. We also confirm that the vacuum expectation value of the energy momentum tensor is vanishing as expected by the supersymmetry. We extend our results to the case of k≠1 for LLM geometries represented by rectangular-shaped Young-diagrams. In analogy with the Coulomb branch of the N=4 super Yang-Mills theory, we argue that the discrete Higgs vacua of the mABJM theory as well as the corresponding LLM geometries are parametrized by the vevs of the chiral primary operators.

Nuclear quadrupole-quadrupole interaction in the inelastic scattering of aligned deuterons from deformed nuclei

International Nuclear Information System (INIS)

Clement, H.; Frick, R.; Graw, G.; Schiemenz, P.; Seichert, N.

1983-01-01

The 2 1 + -excitation of deformed nuclei by tensor polarized deuterons provides an alignment of both nuclei and thus a means to study specifically the quadrupole-quadrupole interaction between both nuclei. The tensor analyzing power Asub(xz)(theta) has been measured for the elastic and inelastic scattering on 24 Mg and 28 Si. The coupled channel analysis including a deformed tensor potential reveals a clear signature of the quadrupole-quadrupole part of the nuclear projectile-target interaction. (orig.)

Simple metric for a magnetized, spinning, deformed mass

Science.gov (United States)

Manko, V. S.; Ruiz, E.

2018-05-01

We present and discuss a 4-parameter stationary axisymmetric solution of the Einstein-Maxwell equations, which is able to describe the exterior field of a rotating magnetized deformed mass. The solution arises as a system of two overlapping corotating magnetized nonequal black holes or hyperextreme disks, and we write it in a concise explicit form that is very suitable for concrete applications. An interesting peculiar feature of this electrovac solution is that it does not develop massless ring singularities outside the stationary limit surface, its first four electric multipole moments being equal to zero; it also has a nontrivial extreme limit, which we elaborate completely in terms of four polynomial factors.

Testing the predictive power of nuclear mass models

International Nuclear Information System (INIS)

Mendoza-Temis, J.; Morales, I.; Barea, J.; Frank, A.; Hirsch, J.G.; Vieyra, J.C. Lopez; Van Isacker, P.; Velazquez, V.

2008-01-01

A number of tests are introduced which probe the ability of nuclear mass models to extrapolate. Three models are analyzed in detail: the liquid drop model, the liquid drop model plus empirical shell corrections and the Duflo-Zuker mass formula. If predicted nuclei are close to the fitted ones, average errors in predicted and fitted masses are similar. However, the challenge of predicting nuclear masses in a region stabilized by shell effects (e.g., the lead region) is far more difficult. The Duflo-Zuker mass formula emerges as a powerful predictive tool

High-temperature deformation and processing maps of Zr-4 metal matrix with dispersed coated surrogate nuclear fuel particles

Science.gov (United States)

Chen, Jing; Liu, Huiqun; Zhang, Ruiqian; Li, Gang; Yi, Danqing; Lin, Gaoyong; Guo, Zhen; Liu, Shaoqiang

2018-06-01

High-temperature compression deformation of a Zr-4 metal matrix with dispersed coated surrogate nuclear fuel particles was investigated at 750 °C-950 °C with a strain rate of 0.01-1.0 s-1 and height reduction of 20%. Scanning electron microscopy was utilized to investigate the influence of the deformation conditions on the microstructure of the composite and damage to the coated surrogate fuel particles. The results indicated that the flow stress of the composite increased with increasing strain rate and decreasing temperature. The true stress-strain curves showed obvious serrated oscillation characteristics. There were stable deformation ranges at the initial deformation stage with low true strain at strain rate 0.01 s-1 for all measured temperatures. Additionally, the coating on the surface of the surrogate nuclear fuel particles was damaged when the Zr-4 matrix was deformed at conditions of high strain rate and low temperature. The deformation stability was obtained from the processing maps and microstructural characterization. The high-temperature deformation activation energy was 354.22, 407.68, and 433.81 kJ/mol at true strains of 0.02, 0.08, and 0.15, respectively. The optimum deformation parameters for the composite were 900-950 °C and 0.01 s-1. These results are expected to provide guidance for subsequent determination of possible hot working processes for this composite.

Deformation mechanisms of a porous structure of the poly(ethylene terephthalate) nuclear track membrane

International Nuclear Information System (INIS)

Ovchinnikov, V.V.

1989-01-01

The deformation mechanisms of a porous structure of the nuclear track membrane made of poly(ethylene terephthalate) are investigated in the temperature range from 333 to 473 K. It is shown that the pore size of the membrane can both decrease and increase. The analytical equation based on the Alfrey mechanical approach to the relaxation deformation of polymers describes the experimental data satisfactorily over the whole range of temperatures and pore radii of the membranes. 21 refs.; 5 figs.; 3 tabs

Facing the challenge of nuclear mass tort processing

International Nuclear Information System (INIS)

Pelzer, Norbert

2017-01-01

A great majority of states do not issue any specific legislation on nuclear mass tort litigations. They apparently build on general traditional practice as most probably already tried and tested in other areas. Some states defer the decision on the way to deal with mass tort claims to the time of the nuclear incident. They insert into their nuclear liability laws respective 'reminders' that contain an invitation or a demand to the legislator to take appropriate steps if and when necessary. Finally, there are a number of states that enacted elaborate regimes on how to react to, and organise, compensation of mass damages after a catastrophic nuclear incident. Among those states are in particular major nuclear states like Canada, India, Japan and the US. They developed compensation schemes where claims for compensation of nuclear damage shall be dealt with by fora that are not regular courts. In some of those states, the fora are exclusively competent without a right to appeal their decisions, while in other states the fora act in parallel or in complement to courts. So the international scenario appears to be somewhat confusing. Of course, sovereign states are free to organise claims processing, including nuclear mass claims processing, as they deem fit. The discretion of states is, however, limited by obligations under public international law. With regard to the victims of nuclear incidents, states are particularly bound by obligations under the 1948 Universal Declaration of Human Rights and other relevant instruments they may be a party to. National nuclear mass claim processing has in particular to comply with the obligation to guarantee 'a fair and public hearing by an independent and impartial tribunal'. With regard to possible international obligations vis-a-vis other states, it has to be taken into account that major nuclear incidents, as a rule, have transboundary detrimental effects. There is always a potential impact on territories

Rock mass modification around a nuclear waste repository in welded tuff

International Nuclear Information System (INIS)

Mack, M.G.; Brandshaug, T.; Brady, B.H.

1989-08-01

This report presents the results of numerical analyses to estimate the extent of rock mass modification resulting from the presence of a High Level Waste (HLW) repository. Changes in rock mass considered are stresses and joint deformations resulting from disposal room excavation and thermal efffects induced by the heat generated by nuclear waste. rock properties and site conditions are taken from the Site Characterization Plan Conceptual Design Report for the potential repository site at Yucca Mountain, Nevada. Analyses were conducted using boundary element and distinct element methods. Room-scale models and repository-scale models were investigated for up to 500 years after waste emplacement. Results of room-scale analyses based on the thermoelastic boundary element model indicate that a zone of modified rock develops around the disposal rooms for both vertical and horizontal waste emplacement. This zone is estimated to extend a distance of roughly two room diameters from the room surface. Results from the repository-scale model, which are based on the thermoelastic boundary element model and the distinct element model, indicate a zone with modified rock mass properties starting approximately 100 m above and below the repository, with a thickness of approximately 200 m above and 150 m below the repository. Slip-prone subhorizontal features are shown to have a substantial effect on rock mass response. The estimates of rock mass modification reflect uncertainties and simplifying assumptions in the models. 32 refs., 57 figs., 1 tab

Formulations and algorithms for problems on rock mass and support deformation during mining

Science.gov (United States)

Seryakov, VM

2018-03-01

The analysis of problem formulations to calculate stress-strain state of mine support and surrounding rocks mass in rock mechanics shows that such formulations incompletely describe the mechanical features of joint deformation in the rock mass–support system. The present paper proposes an algorithm to take into account the actual conditions of rock mass and support interaction and the algorithm implementation method to ensure efficient calculation of stresses in rocks and support.

Global deformation of the Earth, surface mass anomalies, and the geodetic infrastructure required to study these processes

Science.gov (United States)

Kusche, J.; Rietbroek, R.; Gunter, B.; Mark-Willem, J.

2008-12-01

Global deformation of the Earth can be linked to loading caused by mass changes in the atmosphere, the ocean and the terrestrial hydrosphere. World-wide geodetic observation systems like GPS, e.g., the global IGS network, can be used to study the global deformation of the Earth directly and, when other effects are properly modeled, provide information regarding the surface loading mass (e.g., to derive geo-center motion estimates). Vice versa, other observing systems that monitor mass change, either through gravitational changes (GRACE) or through a combination of in-situ and modeled quantities (e.g., the atmosphere, ocean or hydrosphere), can provide indirect information on global deformation. In the framework of the German 'Mass transport and mass distribution' program, we estimate surface mass anomalies at spherical harmonic resolution up to degree and order 30 by linking three complementary data sets in a least squares approach. Our estimates include geo-center motion and the thickness of a spatially uniform layer on top of the ocean surface (that is otherwise estimated from surface fluxes, evaporation and precipitation, and river run-off) as a time-series. As with all current Earth observing systems, each dataset has its own limitations and do not realize homogeneous coverage over the globe. To assess the impact that these limitations might have on current and future deformation and loading mass solutions, a sensitivity study was conducted. Simulated real-case and idealized solutions were explored in which the spatial distribution and quality of GPS, GRACE and OBP data sets were varied. The results show that significant improvements, e.g., over the current GRACE monthly gravity fields, in particular at the low degrees, can be achieved when these solutions are combined with present day GPS and OBP products. Our idealized scenarios also provide quantitative implications on how much surface mass change estimates may improve in the future when improved observing

Validating neural-network refinements of nuclear mass models

Science.gov (United States)

Utama, R.; Piekarewicz, J.

2018-01-01

Background: Nuclear astrophysics centers on the role of nuclear physics in the cosmos. In particular, nuclear masses at the limits of stability are critical in the development of stellar structure and the origin of the elements. Purpose: We aim to test and validate the predictions of recently refined nuclear mass models against the newly published AME2016 compilation. Methods: The basic paradigm underlining the recently refined nuclear mass models is based on existing state-of-the-art models that are subsequently refined through the training of an artificial neural network. Bayesian inference is used to determine the parameters of the neural network so that statistical uncertainties are provided for all model predictions. Results: We observe a significant improvement in the Bayesian neural network (BNN) predictions relative to the corresponding "bare" models when compared to the nearly 50 new masses reported in the AME2016 compilation. Further, AME2016 estimates for the handful of impactful isotopes in the determination of r -process abundances are found to be in fairly good agreement with our theoretical predictions. Indeed, the BNN-improved Duflo-Zuker model predicts a root-mean-square deviation relative to experiment of σrms≃400 keV. Conclusions: Given the excellent performance of the BNN refinement in confronting the recently published AME2016 compilation, we are confident of its critical role in our quest for mass models of the highest quality. Moreover, as uncertainty quantification is at the core of the BNN approach, the improved mass models are in a unique position to identify those nuclei that will have the strongest impact in resolving some of the outstanding questions in nuclear astrophysics.

Nuclear moments and deformation changes in the lightest Pt isotopes measured by laser spectroscopy

CERN Document Server

Roussière, B; Crawford, J; Duong, H T; Genevey, J; Girod, M; Huber, G; Ibrahim, F; Krieg, M; Le Blanc, F; Lee, J K P; Obert, J; Oms, J; Peru, S; Pinard, J; Putaux, J C; Sauvage, J; Sebastian, V; Zemlyanoi, S G; Forkel-Wirth, Doris; Lettry, Jacques

1999-01-01

Laser spectroscopy measurements are performed with the lightest neutron-deficient platinum isotopes using the experimental setup COMPLIS installed at the ISOLDE-Booster facility. The hyperfine spectra of /sup 182-178/Pt and /sup 183m/Pt are recorded for the first time from the optical transition 5d/sup 9/6s/sup 3/D/sub 3/ to 5d/sup 9/6p/sup 3/P/sub 2/. The variation in the mean-square charge radius of these nuclei and the magnetic and quadrupole (for I>or=1) moments of the odd isotope nuclei are found. A large deformation change between the /sup 183g/Pt and /sup 183m/Pt nuclei, quite large inverted odd-even staggering of the charge radius around the neutron midshell N=104, and a nuclear deformation drop in the region A=179 are revealed. All the results are discussed in terms of nuclear shape variation and are compared with the results of Hartree-Fock- Bogoliubov calculations involving the Gogny force. Comparison of the deformation measured from /sup 183g, m/Pt to the odd-odd isotone /sup 184g, m/Au shows that...

Effective masses and the nuclear mean field

International Nuclear Information System (INIS)

Mahaux, C.; Sartor, R.

1985-01-01

The effective mass characterizes the energy dependence of the empirical average nuclear potential. This energy dependence has two different sources, namely the nonlocality in space of the microscopic mean field on the one hand, and its true energy dependence on the other hand. Correspondingly it is convenient to divide the effective mass into two components, the k-mass and the ω-mass. The latter is responsible for the existence of a peak in the energy dependence of the effective mass. This peak is located near the Fermi energy in nuclear matter and in nuclei, as well as in the electron gas, the hard sphere Fermi gas and liquid helium 3. A related phenomenon is the existence of a low energy anomaly in the energy dependence of the optical model potential between two heavy ions. (orig.)

Masses of exotic calcium isotopes pin down nuclear forces

CERN Document Server

Wienholtz, F; Blaum, K; Borgmann, Ch; Breitenfeldt, M; Cakirli, R B; George, S; Herfurth, F; Holt, J D; Kowalska, M; Kreim, S; Lunney, D; Manea, V; Menéndez, J; Neidherr, D; Rosenbusch, M; Schweikhard, L; Schwenk, A; Simonis, J; Stanja, J; Wolf, R N; Zuber, K

2013-01-01

The properties of exotic nuclei on the verge of existence play a fundamental part in our understanding of nuclear interactions. Exceedingly neutron-rich nuclei become sensitive to new aspects of nuclear forces. Calcium, with its doubly magic isotopes $^{40}$Ca and $^{48}$Ca, is an ideal test for nuclear shell evolution, from the valley of stability to the limits of existence. With a closed proton shell, the calcium isotopes mark the frontier for calculations with three-nucleon forces from chiral effective field theory. Whereas predictions for the masses of $^{51}$Ca and $^{52}$Ca have been validated by direct measurements$^4$, it is an open question as to how nuclear masses evolve for heavier calcium isotopes. Here we report the mass determination of the exotic calcium isotopes $^{53}$Ca and $^{54}$Ca, using the multi-reflection time-of-flight mass spectrometer of ISOLTRAP at CERN. The measured masses unambiguously establish a prominent shell closure at neutron number N = 32, in excellent agreement with our t...

Ocean Bottom Deformation Due To Present-Day Mass Redistribution and Its Impact on Sea Level Observations

Science.gov (United States)

Frederikse, Thomas; Riva, Riccardo E. M.; King, Matt A.

2017-12-01

Present-day mass redistribution increases the total ocean mass and, on average, causes the ocean bottom to subside elastically. Therefore, barystatic sea level rise is larger than the resulting global mean geocentric sea level rise, observed by satellite altimetry and GPS-corrected tide gauges. We use realistic estimates of mass redistribution from ice mass loss and land water storage to quantify the resulting ocean bottom deformation and its effect on global and regional ocean volume change estimates. Over 1993-2014, the resulting globally averaged geocentric sea level change is 8% smaller than the barystatic contribution. Over the altimetry domain, the difference is about 5%, and due to this effect, barystatic sea level rise will be underestimated by more than 0.1 mm/yr over 1993-2014. Regional differences are often larger: up to 1 mm/yr over the Arctic Ocean and 0.4 mm/yr in the South Pacific. Ocean bottom deformation should be considered when regional sea level changes are observed in a geocentric reference frame.

Nuclear Structure of 186Re

Science.gov (United States)

2016-12-24

equipotential surfaces defining the shapes of quadrupole-deformed nuclei are shown in Figure 3, in which the e↵ects of varying and are... equipotential surfaces in deformed nuclei, with the axis of nuclear symmetry identified as the z axis. The spherical shape has = 0, while the oblate...Equation (11) are seen to represent the mass-energy contained in the volume of the nucleus, adjusted for the surface tension and the Coulomb

Normal dynamic deformation characteristics of non-consecutive jointed rock masses under impact loads

Science.gov (United States)

Zeng, Sheng; Jiang, Bowei; Sun, Bing

2017-08-01

In order to study deformation characteristics of non-consecutive single jointed rock masses under impact loads, we used the cement mortar materials to make simulative jointed rock mass samples, and tested the samples under impact loads by the drop hammer. Through analyzing the time-history signal of the force and the displacement, first we find that the dynamic compression displacement of the jointed rock mass is significantly larger than that of the intact jointless rock mass, the compression displacement is positively correlated with the joint length and the impact height. Secondly, the vertical compressive displacement of the jointed rock mass is mainly due to the closure of opening joints under small impact loads. Finally, the peak intensity of the intact rock mass is larger than that of the non-consecutive jointed rock mass and negatively correlated with the joint length under the same impact energy.

Characterization of low-mass deformable mirrors and ASIC drivers for high-contrast imaging

Science.gov (United States)

Mejia Prada, Camilo; Yao, Li; Wu, Yuqian; Roberts, Lewis C.; Shelton, Chris; Wu, Xingtao

2017-09-01

The development of compact, high performance Deformable Mirrors (DMs) is one of the most important technological challenges for high-contrast imaging on space missions. Microscale Inc. has fabricated and characterized piezoelectric stack actuator deformable mirrors (PZT-DMs) and Application-Specific Integrated Circuit (ASIC) drivers for direct integration. The DM-ASIC system is designed to eliminate almost all cables, enabling a very compact optical system with low mass and low power consumption. We report on the optical tests used to evaluate the performance of the DM and ASIC units. We also compare the results to the requirements for space-based high-contrast imaging of exoplanets.

Improvements of mass formula and β-decay gross theory

International Nuclear Information System (INIS)

Tachibana, Takahiro

1987-01-01

The nuclear mass greatly decreases when the number of protons Z and neutrons N is simultaneously equal to a magic number (mutual support of magicities). The mass also tends to decrease due to deformation as both N and Z are away from the magic numbers (mutual support of deformations). These two effects are introduced to a nuclear mass formula containing a constant-type shell term to derive a new formula. The mass excess is expressed by a sum of three parts, i.e. gross part, even-odd part and shell part. The gross part, which represents the general nature, consists of two rest mass terms and a coulomb term. The even-odd part is of a typical form with a correction term. The shell part consists of a proton shell term, neutron shell term, third term expressing the two mutual support effects, and fourth term representing a decrease in coulomb energy due to deformation of the nucleus. The improvements made in the β-decay gross theory are associated with the single particle intensity function D 0 GT (E,ε). They are intended for: (1) reproducing the peak that accounts for about a half of the Gamow-Teller intensity, which has recently been found in (p,n) reactions at energies above the isobaric analogue state and (2) explaining the other half by an exponential-type D 0 GT (E,ε). (Nogami, K.)

Dependence of X-Ray Burst Models on Nuclear Masses

Energy Technology Data Exchange (ETDEWEB)

Schatz, H.; Ong, W.-J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States)

2017-08-01

X-ray burst model predictions of light curves and the final composition of the nuclear ashes are affected by uncertain nuclear masses. However, not all of these masses are determined experimentally with sufficient accuracy. Here we identify the remaining nuclear mass uncertainties in X-ray burst models using a one-zone model that takes into account the changes in temperature and density evolution caused by changes in the nuclear physics. Two types of bursts are investigated—a typical mixed H/He burst with a limited rapid proton capture process (rp-process) and an extreme mixed H/He burst with an extended rp-process. When allowing for a 3 σ variation, only three remaining nuclear mass uncertainties affect the light-curve predictions of a typical H/He burst ({sup 27}P, {sup 61}Ga, and {sup 65}As), and only three additional masses affect the composition strongly ({sup 80}Zr, {sup 81}Zr, and {sup 82}Nb). A larger number of mass uncertainties remain to be addressed for the extreme H/He burst, with the most important being {sup 58}Zn, {sup 61}Ga, {sup 62}Ge, {sup 65}As, {sup 66}Se, {sup 78}Y, {sup 79}Y, {sup 79}Zr, {sup 80}Zr, {sup 81}Zr, {sup 82}Zr, {sup 82}Nb, {sup 83}Nb, {sup 86}Tc, {sup 91}Rh, {sup 95}Ag, {sup 98}Cd, {sup 99}In, {sup 100}In, and {sup 101}In. The smallest mass uncertainty that still impacts composition significantly when varied by 3 σ is {sup 85}Mo with 16 keV uncertainty. For one of the identified masses, {sup 27}P, we use the isobaric mass multiplet equation to improve the mass uncertainty, obtaining an atomic mass excess of −716(7) keV. The results provide a roadmap for future experiments at advanced rare isotope beam facilities, where all the identified nuclides are expected to be within reach for precision mass measurements.

Contribution of Deformation to Sea Ice Mass Balance: A Case Study From an N-ICE2015 Storm

Science.gov (United States)

Itkin, Polona; Spreen, Gunnar; Hvidegaard, Sine Munk; Skourup, Henriette; Wilkinson, Jeremy; Gerland, Sebastian; Granskog, Mats A.

2018-01-01

The fastest and most efficient process of gaining sea ice volume is through the mechanical redistribution of mass as a consequence of deformation events. During the ice growth season divergent motion produces leads where new ice grows thermodynamically, while convergent motion fractures the ice and either piles the resultant ice blocks into ridges or rafts one floe under the other. Here we present an exceptionally detailed airborne data set from a 9 km2 area of first year and second year ice in the Transpolar Drift north of Svalbard that allowed us to estimate the redistribution of mass from an observed deformation event. To achieve this level of detail we analyzed changes in sea ice freeboard acquired from two airborne laser scanner surveys just before and right after a deformation event brought on by a passing low-pressure system. A linear regression model based on divergence during this storm can explain 64% of freeboard variability. Over the survey region we estimated that about 1.3% of level sea ice volume was pressed together into deformed ice and the new ice formed in leads in a week after the deformation event would increase the sea ice volume by 0.5%. As the region is impacted by about 15 storms each winter, a simple linear extrapolation would result in about 7% volume increase and 20% deformed ice fraction at the end of the season.

Contribution of deformation to sea-ice mass balance: a case study from an N-ICE2015 storm

DEFF Research Database (Denmark)

Itkin, Polona; Spreen, Gunnar; Hvidegaard, Sine Munk

2018-01-01

The fastest and most efficient process of gaining sea ice volume is through the mechanical redistribution of mass as a consequence of deformation events. During the ice growth season divergent motion produces leads where new ice grows thermodynamically, while convergent motion fractures the ice...... and either piles the resultant ice blocks into ridges or rafts one floe under the other. Here we present an exceptionally detailed airborne dataset from a 9km2 area of first and second year ice in the Transpolar Drift north of Svalbard that allowed us to estimate the redistribution of mass from an observed...... deformation event. To achieve this level of detail we analyzed changes in sea ice freeboard acquired from two airborne laser scanner surveys just before and right after a deformation event brought on by a passing low pressure system. A linear regression model based on divergence during this storm can explain...

Impact of Precision Mass Measurements on Nuclear Physics and Astrophysics

CERN Document Server

Kreim, Susanne; Dilling, Jens; Litvinov, Yuri A

2013-01-01

Among all nuclear ground-state properties, atomic masses are highly specific for each particular combination of neutron and proton number, N and Z, respectively. The data obtained through mass measurements provide details of the nuclear interaction and thus apply to a variety of physics topics. Some of the most crucial questions to be addressed by mass spectrometry of unstable radionuclides are, on the one hand, nuclear forces and structure, describing phenomena such as the so-called neutron-halos or the evolution of magic numbers when moving towards the borders of nuclear existence. On the other hand, the understanding of the processes of element formation in the Universe poses a challenge and requires an accurate knowledge of nuclear astrophysics. Here, precision atomic mass values of a large number of exotic nuclei participating in nucleosynthesis processes are among the key input data in large-scale reaction network calculations.

Hyperscaling relations in mass-deformed conformal gauge theories

International Nuclear Information System (INIS)

Del Debbio, Luigi; Zwicky, Roman

2010-01-01

We present a number of analytical results which should guide the interpretation of lattice data in theories with an infrared fixed point (IRFP) deformed by a mass term δL=-mqq. From renormalization group (RG) arguments we obtain the leading scaling exponent, F∼m η F , for all decay constants of the lowest lying states other than the ones affected by the chiral anomaly and the tensor ones. These scaling relations provide a clear cut way to distinguish a theory with an IRFP from a confining theory with heavy fermions. Moreover, we present a derivation relating the scaling of ∼m η qq to the scaling of the density of eigenvalues of the massless Dirac operator ρ(λ)∼λ η qq . RG arguments yield η qq =(3-γ * )/(1+γ * ) as a function of the mass anomalous dimension γ * at the IRFP. The arguments can be generalized to other condensates such as 2 >∼m 4/(1+γ * ) . We describe a heuristic derivation of the result on the condensates, which provides interesting connections between different approaches. Our results are compared with existing data from numerical studies of SU(2) with two adjoint Dirac fermions.

Performance of 12 DIR algorithms in low-contrast regions for mass and density conserving deformation

International Nuclear Information System (INIS)

Yeo, U. J.; Supple, J. R.; Franich, R. D.; Taylor, M. L.; Smith, R.; Kron, T.

2013-01-01

Purpose: Deformable image registration (DIR) has become a key tool for adaptive radiotherapy to account for inter- and intrafraction organ deformation. Of contemporary interest, the application to deformable dose accumulation requires accurate deformation even in low contrast regions where dose gradients may exist within near-uniform tissues. One expects high-contrast features to generally be deformed more accurately by DIR algorithms. The authors systematically assess the accuracy of 12 DIR algorithms and quantitatively examine, in particular, low-contrast regions, where accuracy has not previously been established.Methods: This work investigates DIR algorithms in three dimensions using deformable gel (DEFGEL) [U. J. Yeo, M. L. Taylor, L. Dunn, R. L. Smith, T. Kron, and R. D. Franich, “A novel methodology for 3D deformable dosimetry,” Med. Phys. 39, 2203–2213 (2012)], for application to mass- and density-conserving deformations. CT images of DEFGEL phantoms with 16 fiducial markers (FMs) implanted were acquired in deformed and undeformed states for three different representative deformation geometries. Nonrigid image registration was performed using 12 common algorithms in the public domain. The optimum parameter setup was identified for each algorithm and each was tested for deformation accuracy in three scenarios: (I) original images of the DEFGEL with 16 FMs; (II) images with eight of the FMs mathematically erased; and (III) images with all FMs mathematically erased. The deformation vector fields obtained for scenarios II and III were then applied to the original images containing all 16 FMs. The locations of the FMs estimated by the algorithms were compared to actual locations determined by CT imaging. The accuracy of the algorithms was assessed by evaluation of three-dimensional vectors between true marker locations and predicted marker locations.Results: The mean magnitude of 16 error vectors per sample ranged from 0.3 to 3.7, 1.0 to 6.3, and 1.3 to 7

Extending and refining the nuclear mass surface with ISOLTRAP and MISTRAL

CERN Document Server

Lunney, M D

2000-01-01

Through the nuclear binding energy the atomic mass gives us important information about nuclear structure. Viewing the ensemble of mass data over the nuclear chart, we can examine the hills and valleys that form this surface and make hypotheses about the effects of certain nuclear configurations. To unveil these effects, mass measurements of very high precision (10$^{-6}$) are required. Two experiments at ISOLDE pursue this effort of nuclear cartography the tandem Penning trap spectrometer ISOLTRAP and the radiofrequency transmission spectrometer MISTRAL. Between them, the masses of almost 150 nuclides have been measured from stable isotopes to those with half-lives as short as 30 ms. Both experiments rely on good optical properties of a low energy ion beam and are thus well suited to the ISOLDE facility. (30 refs).

Infinite nuclear matter model and mass formulae for nuclei

International Nuclear Information System (INIS)

Satpathy, L.

2016-01-01

The matter composed of the nucleus is a quantum-mechanical interacting many-fermionic system. However, the shell and classical liquid drop have been taken as the two main features of nuclear dynamics, which have guided the evolution of nuclear physics. These two features can be considered as the macroscopic manifestation of the microscopic dynamics of the nucleons at fundamental level. Various mass formulae have been developed based on either of these features over the years, resulting in many ambiguities and uncertainties posing many challenges in this field. Keeping this in view, Infinite Nuclear Matter (INM) model has been developed during last couple of decades with a many-body theoretical foundation employing the celebrated Hugenholtz-Van Hove theorem, quite appropriate for the interacting quantum-mechanical nuclear system. A mass formula called INM mass formula based on this model yields rms deviation of 342 keV being the lowest in literature. Some of the highlights of its result includes its determination of INM density in agreement with the electron scattering data leading to the resolution of the long standing 'r 0 -paradox' it predicts new magic numbers giving rise to new island of stability in the drip-line regions. This is the manifestation of a new phenomenon where shell-effect over comes the repulsive component of nucleon-nucleon force resulting in the broadening of the stability peninsula. Shell quenching in N= 82,and N= 126 shells, and several islands of inversion have been predicted. The model determines the empirical value of the nuclear compression modulus, using high precission 4500 data comprising nuclear masses, neutron and proton separation energies. The talk will give a critical review of the field of mass formula and our understanding of nuclear dynamics as a whole

Study of the nuclear potential in the mass region of supercritical systems by means of phenomenological models

International Nuclear Information System (INIS)

Seiwert, M.

1985-01-01

In the present thesis different potential models were extended up to deformed nuclei. The influence of the deformations, orientations, and the nuclear atmosphere on the nuclear potential were analyzed. The double-folding integral was also solved for adiabatic nuclear shapes. The unrealistic binding-energy contributions occurring in the double-folding model were replaced by realistic binding energies by a renormalization procedure. The extended proximity potential, the renormalized double-folding model, and the Yukawa-plus-exponential model were applied to the calculation of the potential of supercritical systems. The resulting potentials of the different models are nonuniform. (orig./HSI) [de

Simultaneous evaluation of the shell and pairing corrections to the nuclear deformation energy: the case of odd-systems

International Nuclear Information System (INIS)

Benhamouda, N.; Oudih, M.R.

2002-01-01

A method of simultaneous evaluation of the shell and pairing corrections to the nuclear deformation energy, recently proposed for the even-even nuclei, is generalized to the case of odd systems. * By means of the blocked-level technique, a level density with explicit dependence on pairing correlations is defined. The microscopic corrections to the deformation energy are then determined by a procedure which is analogous to that of Strutinsky. The method is applied to the ground state of Europium isotopes using the single-particle energies of a deformed Woods-Saxon mean-field. The obtained results are in good agreement with the experimental values

Study of Triaxial deformation variable γ in even - even nuclei

International Nuclear Information System (INIS)

Singh, Yuvraj; Gupta, K.K.; Bihari, Chhail; Sharma, Aparna; Varshney, A.K.; Singh, M.; Gupta, D.K.; Varshney, Mani; Dhiman, S.K.

2011-01-01

The deformation parameters β and γ of the collective model are basic description of the nuclear equilibrium shape and structure, while values for these variables have been discussed for many nuclei. A systematic study in mass region A = 120-140 and A = 150 -180 can never be less revealing, such study has been presented, in A = 90 -120 for Mo, Ru and Pd nuclei where β and γ both vary strongly

Analysis of displacement and strain data for the determination of the in-situ deformability of rock masses

International Nuclear Information System (INIS)

de la Cruz, R.V.; Karfakis, M.; Kim, K.

1981-01-01

The in-situ deformability of a highly jointed basalt rock mass was determined by two distinctly different methods: one, by the NX-borehole jack method where the displacements of opposing curved platens were related to the applied hydraulic pressures, and; two, by the modified Goodman jack method where the tangential strains on the borehole walls were related to the induced tangential stresses. The modulus obtained by the modified Goodman jack method were much higher than those obtained by the NX-borehole jack method. To explain the discrepancy, the influence of fractures and test variables such as depth, orientation, hole number and applied pressure on the calculated modulus of the rock mass were analyzed by factorial analysis and it was found that the orientations and depths of measurement has statistically significant effects. The in-situ deformability values obtained by non-linear regression analysis were also found comparable with other measurements and empirically predicted values for the basalt rock mass

Multiple-hook fixation in revision spinal deformity surgery for patients with a previous multilevel fusion mass: technical note and preliminary outcomes.

Science.gov (United States)

Liu, Ning; Wood, Kirkham B

2017-03-01

OBJECTIVE A previous multilevel fusion mass encountered during revision spinal deformity surgery may obscure anatomical landmarks, making instrumentation unworkable or incurring substantial blood loss and operative time. This study introduced a surgical technique of multiple-hook fixation for fixating previous multilevel fusion masses in revision spinal deformity surgeries and then evaluated its outcomes. METHODS Patients with a previous multilevel fusion mass who underwent revision corrective surgery down to the lumbosacral junction were retrospectively studied. Multiple hooks were used to fixate the fusion mass and linked to distal pedicle screws in the lumbosacral-pelvic complex. Radiological and clinical outcomes were evaluated. RESULTS The charts of 8 consecutive patients with spinal deformity were retrospectively reviewed (7 women, 1 man; mean age 56 years). The primary diagnoses included flat-back deformity (6 cases), thoracolumbar kyphoscoliosis (1 case), and lumbar spondylosis secondary to a previous scoliosis fusion (1 case). The mean follow-up duration was 30.1 months. Operations were performed at T3/4-ilium (4 cases), T7-ilium (1 case), T6-S1 (1 case), T12-S1 (1 case), and T9-L5 (1 case). Of 8 patients, 7 had sagittal imbalance preoperatively, and their mean C-7 plumb line improved from 10.8 ± 2.9 cm preoperatively to 5.3 ± 3.6 cm at final follow-up (p = 0.003). The mean lumbar lordosis of these patients at final follow-up was significantly greater than that preoperatively (35.2° ± 12.6° vs 16.8° ± 11.8°, respectively; p = 0.005). Two perioperative complications included osteotomy-related leg weakness in 1 patient and a stitch abscess in another. CONCLUSIONS The multiple-hook technique provides a viable alternative option for fixating a previous multilevel fusion mass in revision spinal deformity surgery.

The origin of nuclear mass number dependence in EMC-effect

International Nuclear Information System (INIS)

Kurihara, Y.; Date, S.; Nakamura, A.; Sato, H.; Sumiyoshi, H.; Yoshinada, K.

1985-03-01

The origin of the mass number dependence of the nucleon structure functions extracted from the deep inelastic lepton-nucleus scattering is investigated by factorizing the structure function into A and x dependent parts. It is found that the mass number dependence is determined by the probability of exotic components in multi-nucleon overlap. This suggests that the deformation of the nucleon structure function is caused by the interaction among nucleons during their overlap. (author)

Mass measurements of neutron-rich strontium and rubidium isotopes in the region $A \\approx 100$ and development of an electrospray ionization ion source

CERN Document Server

de Roubin, Antoine

An extension of the atomic mass surface in the region $A \\approx 100$ is performed via mass measurements of the $^{100−102}$Sr and $^{100−102}$Rb isotopes with the ion-trap mass spectrometer ISOLTRAP at CERN-ISOLDE. The first direct mass measurements of $^{102}$Sr and $^{101,102}$Rb are reported here. These measurements confirm the continuation of the region of nuclear deformation with the increase of neutron number, at least as far as $N = 65$. In order to interpret the deformation in the strontium isotopic chain and to determine whether an onset of deformation is present in heavier krypton isotopes, a comparison is made between experimental values and theoretical calculations available in the literature. To complete this comparison, Hartree-Fock-Bogoliubov calculations for even and odd isotopes are also presented, illustrating the competition of nuclear shapes in the region. The development of an electrospray ionization ion source is presented. This source can deliver a large range of isobaric masses ...

Mass spectrometric analysis for nuclear safeguards

OpenAIRE

BOULYGA S.; KONEGGER-KAPPEL S.; RICHTER Stephan; SANGELY L.

2014-01-01

Mass spectrometry is currently being implemented in a wide spectrum of research and industrial areas, such as material sciences, cosmo- and geochemistry, biology and medicine, to name just a few. Research and development in nuclear safeguards is closely related to the general field of “Peace Research”; representing a specific application area for analytical sciences in general and for mass spectrometry in particular. According to Albert Einstein “peace cannot be kept by force. It only can be ...

q-Deformed Kink solutions

International Nuclear Information System (INIS)

Lima, A.F. de

2003-01-01

The q-deformed kink of the λφ 4 -model is obtained via the normalisable ground state eigenfunction of a fluctuation operator associated with the q-deformed hyperbolic functions. The kink mass, the bosonic zero-mode and the q-deformed potential in 1+1 dimensions are found. (author)

Simultaneous evaluation of the shell and pairing corrections to the nuclear deformation energy: the case of odd-systems

Energy Technology Data Exchange (ETDEWEB)

Benhamouda, N [Laboratoire de Physique Theoique, Faculte des Sciences, USTHB BP 32 El-Alia, 16111 Bab-Ezzouar, Algers (Algeria); Oudih, M R [CRNA, 2. Bd Frantz Fanon, BP 399 Alger-Gare, Algers (Algeria)

2002-09-15

A method of simultaneous evaluation of the shell and pairing corrections to the nuclear deformation energy, recently proposed for the even-even nuclei, is generalized to the case of odd systems. {sup *} By means of the blocked-level technique, a level density with explicit dependence on pairing correlations is defined. The microscopic corrections to the deformation energy are then determined by a procedure which is analogous to that of Strutinsky. The method is applied to the ground state of Europium isotopes using the single-particle energies of a deformed Woods-Saxon mean-field. The obtained results are in good agreement with the experimental values.

ADM mass and quasilocal energy of black hole in the deformed Horava-Lifshitz gravity

International Nuclear Information System (INIS)

Myung, Yun Soo

2010-01-01

Inspired by the Einstein-Born-Infeld black hole, we introduce the isolated horizon to study the Kehagias-Sfetsos (KS) black hole in the deformed Horava-Lifshitz gravity. This is because the KS black hole is more close to the Einstein-Born-Infeld black hole than the Reissner-Nordstroem black hole. We find the horizon and ADM masses by using the first law of thermodynamics and the area-law entropy. The mass parameter m is identified with the quasilocal energy at infinity. Accordingly, we discuss the phase transition between the KS and Schwarzschild black holes by considering the heat capacity and free energy.

Pairing and deformation effects in nuclear excitation spectra

Energy Technology Data Exchange (ETDEWEB)

Repko, A. [Slovak Academy of Sciences, Institute of Physics, Bratislava (Slovakia); Kvasil, J. [Charles University, Institute of Particle and Nuclear Physics, Prague (Czech Republic); Nesterenko, V.O. [Joint Institute for Nuclear Research, Laboratory of Theoretical Physics, Dubna (Russian Federation); State University ' ' Dubna' ' , Dubna (Russian Federation); Reinhard, P.G. [Universitaet Erlangen, Institut fuer Theoretische Physik II, Erlangen (Germany)

2017-11-15

We investigate effects of pairing and of quadrupole deformation on two sorts of nuclear excitations, γ-vibrational K{sup π} = 2{sup +} states and dipole resonances (isovector dipole, pygmy, compression, toroidal). The analysis is performed within the quasiparticle random phase approximation (QRPA) based on the Skyrme energy functional using the Skyrme parametrization SLy6. Particular attention is paid to i) the role of the particle-particle (pp) channel in the residual interaction of QRPA, ii) comparison of volume pairing (VP) and surface pairing (SP), iii) peculiarities of deformation splitting in the various resonances. We find that the impact of the pp-channel on the considered excitations is negligible. This conclusion applies also to any other excitation except for the K{sup π} = 0{sup +} states. Furthermore, the difference between VP and SP is found small (with exception of peak height in the toroidal mode). In the low-energy isovector dipole (pygmy) and isoscalar toroidal modes, the branch K{sup π} = 1{sup -} is shown to dominate over the K{sup π} = 0{sup -} one in the range of excitation energy E < 8-10 MeV. The effect becomes impressive for the toroidal resonance whose low-energy part is concentrated in a high peak of almost pure K{sup π} = 1{sup -} nature. This peculiarity may be used as a fingerprint of the toroidal mode in future experiments. The interplay between pygmy, toroidal and compression resonances is discussed, the interpretation of the observed isoscalar giant dipole resonance is partly revised. (orig.)

Theories of Variable Mass Particles and Low Energy Nuclear Phenomena

Science.gov (United States)

Davidson, Mark

2014-02-01

Variable particle masses have sometimes been invoked to explain observed anomalies in low energy nuclear reactions (LENR). Such behavior has never been observed directly, and is not considered possible in theoretical nuclear physics. Nevertheless, there are covariant off-mass-shell theories of relativistic particle dynamics, based on works by Fock, Stueckelberg, Feynman, Greenberger, Horwitz, and others. We review some of these and we also consider virtual particles that arise in conventional Feynman diagrams in relativistic field theories. Effective Lagrangian models incorporating variable mass particle theories might be useful in describing anomalous nuclear reactions by combining mass shifts together with resonant tunneling and other effects. A detailed model for resonant fusion in a deuterium molecule with off-shell deuterons and electrons is presented as an example. Experimental means of observing such off-shell behavior directly, if it exists, is proposed and described. Brief explanations for elemental transmutation and formation of micro-craters are also given, and an alternative mechanism for the mass shift in the Widom-Larsen theory is presented. If variable mass theories were to find experimental support from LENR, then they would undoubtedly have important implications for the foundations of quantum mechanics, and practical applications may arise.

Nuclear clustering - a cluster core model study

International Nuclear Information System (INIS)

Paul Selvi, G.; Nandhini, N.; Balasubramaniam, M.

2015-01-01

Nuclear clustering, similar to other clustering phenomenon in nature is a much warranted study, since it would help us in understanding the nature of binding of the nucleons inside the nucleus, closed shell behaviour when the system is highly deformed, dynamics and structure at extremes. Several models account for the clustering phenomenon of nuclei. We present in this work, a cluster core model study of nuclear clustering in light mass nuclei

Quasiequilibrium models for triaxially deformed rotating compact stars

International Nuclear Information System (INIS)

Huang Xing; Markakis, Charalampos; Sugiyama, Noriyuki; Uryu, Koji

2008-01-01

Quasiequilibrium models of rapidly rotating triaxially deformed stars are computed in general relativistic gravity, assuming a conformally flat spatial geometry (Isenberg-Wilson-Mathews formulation) and a polytropic equation of state. Highly deformed solutions are calculated on the initial slice covered by spherical coordinate grids, centered at the source, in all angular directions up to a large truncation radius. Constant rest mass sequences are calculated from nearly axisymmetric to maximally deformed triaxial configurations. Selected parameters are to model (proto-) neutron stars; the compactness is M/R=0.001, 0.1, 0.14, and 0.2 for polytropic index n=0.3 and M/R=0.001, 0.1, 0.12, and 0.14 for n=0.5, where M/R refers to that of a nonrotating spherical star having the same rest mass. We confirmed that the triaxial solutions exist for these parameters as in the case of Newtonian polytropes. However, it is also found that the triaxial sequences become shorter for higher compactness, and those disappear at a certain large compactness for the n=0.5 case. In the scenario of the contraction of proto-neutron stars being subject to strong viscosity and rapid cooling, it is plausible that, once the viscosity driven secular instability sets in during the contraction, the proto-neutron stars are always maximally deformed triaxial configurations, as long as the compactness and the equation of state parameters allow such triaxial sequences. Detection of gravitational waves from such sources may be used as another probe for the nuclear equation of state.

Steam Generator control in Nuclear Power Plants by water mass inventory

Energy Technology Data Exchange (ETDEWEB)

Dong Wei [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States); Doster, J. Michael [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States)], E-mail: doster@eos.ncsu.edu; Mayo, Charles W. [North Carolina State University, Department of Nuclear Engineering, Box 7909, Raleigh, NC 27695-7909 (United States)

2008-04-15

Control of water mass inventory in Nuclear Steam Generators is important to insure sufficient cooling of the nuclear reactor. Since downcomer water level is measurable, and a reasonable indication of water mass inventory near steady-state, conventional feedwater control system designs attempt to maintain downcomer water level within a relatively narrow operational band. However, downcomer water level can temporarily react in a reverse manner to water mass inventory changes, commonly known as shrink and swell effects. These complications are accentuated during start-up or low power conditions. As a result, automatic or manual control of water level is difficult and can lead to high reactor trip rates. This paper introduces a new feedwater control strategy for Nuclear Steam Generators. The new method directly controls water mass inventory instead of downcomer water level, eliminating complications from shrink and swell all together. However, water mass inventory is not measurable, requiring an online estimator to provide a mass inventory signal based on measurable plant parameters. Since the thermal-hydraulic response of a Steam Generator is highly nonlinear, a linear state-observer is not feasible. In addition, difficulties in obtaining flow regime and density information within the Steam Generator make an estimator based on analytical methods impractical at this time. This work employs a water mass estimator based on feedforward neural networks. By properly choosing and training the neural network, mass signals can be obtained which are suitable for stable, closed-loop water mass inventory control. Theoretical analysis and simulation results show that water mass control can significantly improve the operation and safety of Nuclear Steam Generators.

Steam Generator control in Nuclear Power Plants by water mass inventory

International Nuclear Information System (INIS)

Dong Wei; Doster, J. Michael; Mayo, Charles W.

2008-01-01

Control of water mass inventory in Nuclear Steam Generators is important to insure sufficient cooling of the nuclear reactor. Since downcomer water level is measurable, and a reasonable indication of water mass inventory near steady-state, conventional feedwater control system designs attempt to maintain downcomer water level within a relatively narrow operational band. However, downcomer water level can temporarily react in a reverse manner to water mass inventory changes, commonly known as shrink and swell effects. These complications are accentuated during start-up or low power conditions. As a result, automatic or manual control of water level is difficult and can lead to high reactor trip rates. This paper introduces a new feedwater control strategy for Nuclear Steam Generators. The new method directly controls water mass inventory instead of downcomer water level, eliminating complications from shrink and swell all together. However, water mass inventory is not measurable, requiring an online estimator to provide a mass inventory signal based on measurable plant parameters. Since the thermal-hydraulic response of a Steam Generator is highly nonlinear, a linear state-observer is not feasible. In addition, difficulties in obtaining flow regime and density information within the Steam Generator make an estimator based on analytical methods impractical at this time. This work employs a water mass estimator based on feedforward neural networks. By properly choosing and training the neural network, mass signals can be obtained which are suitable for stable, closed-loop water mass inventory control. Theoretical analysis and simulation results show that water mass control can significantly improve the operation and safety of Nuclear Steam Generators

In-silico oncology: an approximate model of brain tumor mass effect based on directly manipulated free form deformation

Energy Technology Data Exchange (ETDEWEB)

Becker, Stefan; Mang, Andreas; Toma, Alina; Buzug, Thorsten M. [University of Luebeck (Germany). Institute of Medical Engineering

2010-12-15

The present work introduces a novel method for approximating mass effect of primary brain tumors. The spatio-temporal dynamics of cancerous cells are modeled by means of a deterministic reaction-diffusion equation. Diffusion tensor information obtained from a probabilistic diffusion tensor imaging atlas is incorporated into the model to simulate anisotropic diffusion of cancerous cells. To account for the expansive nature of the tumor, the computed net cell density of malignant cells is linked to a parametric deformation model. This mass effect model is based on the so-called directly manipulated free form deformation. Spatial correspondence between two successive simulation steps is established by tracking landmarks, which are attached to the boundary of the gross tumor volume. The movement of these landmarks is used to compute the new configuration of the control points and, hence, determines the resulting deformation. To prevent a deformation of rigid structures (i.e. the skull), fixed shielding landmarks are introduced. In a refinement step, an adaptive landmark scheme ensures a dense sampling of the tumor isosurface, which in turn allows for an appropriate representation of the tumor shape. The influence of different parameters on the model is demonstrated by a set of simulations. Additionally, simulation results are qualitatively compared to an exemplary set of clinical magnetic resonance images of patients diagnosed with high-grade glioma. Careful visual inspection of the results demonstrates the potential of the implemented model and provides first evidence that the computed approximation of tumor mass effect is sensible. The shape of diffusive brain tumors (glioblastoma multiforme) can be recovered and approximately matches the observations in real clinical data. (orig.)

Mass spectrometry in nuclear technology - a review of application of thermal ionization mass spectrometry in fuel reprocessing plants. PD-7-1

International Nuclear Information System (INIS)

Dakshinamoorthy, A.

2007-01-01

Mass spectrometry finds the widespread application in nuclear science and technology due to the fact that it can be employed for isotope composition measurements of different elements of interest and also concentration measurements of these elements using isotope dilution techniques. Thermal ionization mass spectrometer (TIMS), Inductively coupled plasma mass spectrometer (ICP-MS) and gas chromatography mass spectrometer (GC-MS) are the different types of mass spectrometers used in nuclear industry for the analyses of isotope composition of special nuclear material, trace impurities in nuclear fuels and components and characterization of various solvents respectively. Among them, TIMS plays a vital role in the nuclear fuel cycle in determining precisely the isotope composition of uranium, plutonium, D/H ratio in heavy water etc. TIMS is an indispensable analytical tool for nuclear material accounting at the input stage of a reprocessing plant by carrying out precise and accurate concentration measurement of plutonium and uranium by isotope dilution mass spectrometry (IDMS). It is the only accepted measurement technique for the purpose because of its high precision, better sensitivity and no quantitative separation is needed. The isotope abundance measurements of uranium and plutonium at this point are also useful for burn-up studies and isotope correlations. Mass spectrometric analysis of uranium and plutonium is also required for nuclear data measurements and calibrating other chemical methods

Burnup determination of mass spectrometry for nuclear fuels

International Nuclear Information System (INIS)

Zhang Chunhua.

1987-01-01

The various methods currently being used in burnup determination of nuclear fuels are studied and reviewed. The mass spectrometry method of destructive testing is discussed emphatically. The burnup determination of mass spectrometry includes heavy isotopic abundance ratio method and isotope dilution mass spectrometry used as burnup indicator for the fission products. The former is applied to high burnup level, but the later to various burnup level. According to experiences, some problems which should be noticed in burnup determination of mass spectrometry are presented

Recent status of the studies of nuclear masses and β-decay

International Nuclear Information System (INIS)

Yamada, Masami

1996-01-01

The recent status of the above studies was explained, especially, nuclear masses were described from the aspect of probability theory and that of β-decay suggested that the first forbidden transition was hindered between the ground states. We have to study various systematics in order to know the mass surface, Way-Yamada-Matumoto type systematics is better to check the experimental nuclear masses. The gross theory is very useful to understand the general aspect of β-decay. The understanding method of mass surface, systematic check of mass and hindrance of the first forbidden transition at rank 1 were explained. (S.Y.)

Recent status of the studies of nuclear masses and {beta}-decay

Energy Technology Data Exchange (ETDEWEB)

Yamada, Masami [Waseda Univ., Tokyo (Japan). Advanced Research Center for Science and Engineering

1996-05-01

The recent status of the above studies was explained, especially, nuclear masses were described from the aspect of probability theory and that of {beta}-decay suggested that the first forbidden transition was hindered between the ground states. We have to study various systematics in order to know the mass surface, Way-Yamada-Matumoto type systematics is better to check the experimental nuclear masses. The gross theory is very useful to understand the general aspect of {beta}-decay. The understanding method of mass surface, systematic check of mass and hindrance of the first forbidden transition at rank 1 were explained. (S.Y.)

Nuclear physics: Macroscopic aspects

International Nuclear Information System (INIS)

Swiatecki, W.J.

1993-12-01

A systematic macroscopic, leptodermous approach to nuclear statics and dynamics is described, based formally on the assumptions ℎ → 0 and b/R << 1, where b is the surface diffuseness and R the nuclear radius. The resulting static model of shell-corrected nuclear binding energies and deformabilities is accurate to better than 1 part in a thousand and yields a firm determination of the principal properties of the nuclear fluid. As regards dynamics, the above approach suggests that nuclear shape evolutions will often be dominated by dissipation, but quantitative comparisons with experimental data are more difficult than in the case of statics. In its simplest liquid drop version the model exhibits interesting formal connections to the classic astronomical problem of rotating gravitating masses

Nuclear quadrupole deformations and anisotropic angular correlations between K x rays and gamma rays

International Nuclear Information System (INIS)

Khalil, A.E.

1983-01-01

Anisotropic angular correlation between gamma rays and the K x rays following the K conversion from nuclei with large static deformations has been studied. A complete theoretical expression for 181 Ta, the second known case of this phenomenon, is presented. This case involves several mixed nuclear transitions which result in 62% of the x rays arising from magnetic dipole internal-conversion processes and 38% arising from electric-quadrupole internal-conversion processes

Deformation of in-service pressure tubes

International Nuclear Information System (INIS)

Sarce, A.L.

1993-01-01

Candu type nuclear reactor pressure tubes suffer deformations during operation. This are consequences of irradiation growth and creep. By means of a computer code which takes into account the material microstructure, the above mentioned deformations are calculated, and results are compared with corresponding values measured at Embalse nuclear power plant. The calculations make explicit inclusion of intergranular stresses caused by an isotropy in the material. (author). 1 ref

Application of accelerator mass spectrometry in nuclear science

International Nuclear Information System (INIS)

Wang Xiaobo; Hu Jinjun; Wang Huijuan; Guan Yongjing; Wang Wei

2013-01-01

Accelerator mass spectrometry (AMS) is a promising method to provide extreme sensitivity measurements of the production yields of long-lived radioisotopes, which cannot be detected by other methods. AMS technique plays an important role in the research of nuclear physics, as well as the application field of AMS covered nuclear science and technology, life science, earth science, environmental science, archaeology etc. The newest AMS field is that of actinide, particularly U and Pu, isotopic assay with expanding applications in nuclear safeguards and monitoring, and as a modern bomb-fallout tracer for atmospheric transport and surface sediment movement. This paper reviews the applications of AMS in the research of nuclear energy and nuclear security including the research of half life of radionuclides, cross section of nuclear reaction. (authors)

Estimation of unknown nuclear masses by means of the generalized mass relations. Pt. 3

International Nuclear Information System (INIS)

Popa, S.M.

1980-01-01

A survey of the estimations of the unknown nuclear masses by means of the generalized mass relations is presented. One discusses the new hypotheses supplementing the original general Garvey-Kelson scheme, reviewing the generalized mass relations and formulae, according to the present status of this new formalism. A critical discussions is given of the reliability of these new Garvey-Kelson type extrapolation procedures. (author)

The odd-proton effects on the potential energy surfaces of odd mass Tl, Au, Ir and Re isotopes

CERN Document Server

De Wieclawik, W; Larsson, S E; Leander, G; Vieu, C; Dionisio, J S

1976-01-01

The total potential energy surfaces of thallium, gold, iridium and rhenium odd mass isotopes are calculated microscopically as functions of the quadrupole deformation, epsilon /sub 2/, when the odd protons occupy definite orbitals. The nuclear shapes and the static equilibrium deformations of these nuclei are deduced from the results of these calculations for the proton orbitals nearest to the Fermi level. The influence of the hexadecapole deformation, epsilon /sub 4/, on these results is investigated too. Finally, a few experimental data available for these odd mass nuclei are correlated to the corresponding theoretical results. (16 refs).

Coriolis force and nuclear deformation: cadmium and lead isotopes results with the EUROBALL gamma multidetector

International Nuclear Information System (INIS)

Buforn, Nadege

2001-01-01

This work is devoted to the study of the nuclear matter at high rotational frequency. Thanks to the new generation of γ-ray multidetector array, as EUROGAM then EUROBALL, we propose to identify two sorts of nuclei belonging to two different mass region. Their identification is based on the detection of their γ-rays of des-excitation. We will follow the evolution of the influence of the Coriolis force at the microscopic scale. The cadmium nuclei 113-116 Cd have been populated using heavy-ion induced fission reaction ( 28 Si+ 176 Yb at 145 MeV). Decoupled bands have been identified in odd-nuclei, produced for the first time at high spin. As they were considered as the best example of vibrational nuclei during their studies by radioactivity, they exhibit a small prolate deformation, confirmed by our microscopic calculations performed for even-even nuclei. The odd superdeformed nucleus 197 Pb have been studied via a fusion-evaporation reaction ( 18 O+ 186 W at 117 MeV). We have established the cross-talk transitions between the two signature partners. The experimental measurement of the branching ratio B(M1)/B(E2) allows us to extract the magnetic properties of the superdeformed matter, conforming the lack of quenching for the neutrons. The Coriolis force depends on the nuclei deformation and on the individual configuration. In cadmium nuclei, the single neutron νh 11/2 , Ω=1/2 is decoupled from the motion of the core, whereas in superdeformed nuclei, the Coriolis effect is much weaker on the νj 15/2 , Ω = 5/2 neutron. (author)

Influence of Aging Products on Tensile Deformation Behavior of Al-0.62 mass%Mg-0.32 mass%Si Alloy

DEFF Research Database (Denmark)

Akiyoshi, Ryutaro; Ikeda, Ken-ichi; Hata, Satoshi

2015-01-01

mechanism, by estimating the Orowan stress and considering crystal structure of beta '' precipitates. In contrast, the aged alloys with Mg-Si clusters showed excellent performance of uniform elongation due to large work hardening compared to those of the alloy with beta '' precipitates. Dislocations......Tensile tests and microstructural observations were carried out to investigate the influence of aging products on tensile deformation behavior of Al-0.62 mass. Mg-0.32 mass-Si alloy. Solution-treated alloys were aged to form needle-like beta ''. precipitates or Mg-Si clusters. The aged alloy...... with beta '' precipitates showed higher yield stress than that with Mg-Si clusters. Transmission electron microscopy observations revealed that the beta '' precipitates pinned dislocations. It was suggested that the strengthening types of the alloy with beta '' precipitates were both Orowan and cutting...

Relationship between the rock mass deformation and places of occurrence of seismological events

Energy Technology Data Exchange (ETDEWEB)

Janusz Makowka; Jozef Kabiesz; Lin-ming Ddou [Central Mining Institute, Katowice (Poland)

2009-09-15

Static effort of rock mass very rarely causes of rock burst in Polish coal mines. Rock bursts with source in the seismic tremor within the roof rock layers are prevailing. A seismic tremor is an effect of rupture or sliding in roof layers above the exploited panel in coal seam, sometime in a distance from actual exploitation. Sliding, as a rule occurs in fault zone and tremors in it are expected, but monolithic layer rupture is very hard to predict. In a past few years a practice of analyzing state of deformation in high energy seismic tremors zones has been employed. It let gathering experience thanks to witch determination of dangerous shape of reformatted roof is possible. In the paper some typical forms of roof rocks deformations leading to seismic tremor occurrence will be presented. In general these are various types of multidirectional rock layers bending. Real examples of seismic events and rock bursts in the Czech Republic will be shown. 5 refs., 6 figs.

Investigation of the proton-neutron interaction by high-precision nuclear mass measurements

CERN Multimedia

Savreux, R P; Akkus, B

2007-01-01

We propose to measure the atomic masses of a series of short-lived nuclides, including $^{70}$Ni, $^{122-130}$Cd, $^{134}$Sn, $^{138,140}$Xe, $^{207-210}$Hg, and $^{223-225}$Rn, that contribute to the investigation of the proton-neutron interaction and its role in nuclear structure. The high-precision mass measurements are planned for the Penning trap mass spectrometer ISOLTRAP that reaches the required precision of 10 keV in the nuclear mass determination.

Properties of nuclear matter from macroscopic–microscopic mass formulas

Directory of Open Access Journals (Sweden)

Ning Wang

2015-12-01

Full Text Available Based on the standard Skyrme energy density functionals together with the extended Thomas–Fermi approach, the properties of symmetric and asymmetric nuclear matter represented in two macroscopic–microscopic mass formulas: Lublin–Strasbourg nuclear drop energy (LSD formula and Weizsäcker–Skyrme (WS* formula, are extracted through matching the energy per particle of finite nuclei. For LSD and WS*, the obtained incompressibility coefficients of symmetric nuclear matter are K∞=230±11 MeV and 235±11 MeV, respectively. The slope parameter of symmetry energy at saturation density is L=41.6±7.6 MeV for LSD and 51.5±9.6 MeV for WS*, respectively, which is compatible with the liquid-drop analysis of Lattimer and Lim [4]. The density dependence of the mean-field isoscalar and isovector effective mass, and the neutron–proton effective masses splitting for neutron matter are simultaneously investigated. The results are generally consistent with those from the Skyrme Hartree–Fock–Bogoliubov calculations and nucleon optical potentials, and the standard deviations are large and increase rapidly with density. A better constraint for the effective mass is helpful to reduce uncertainties of the depth of the mean-field potential.

Role of nesprin-1 in nuclear deformation in endothelial cells under static and uniaxial stretching conditions

International Nuclear Information System (INIS)

Anno, Toshiro; Sakamoto, Naoya; Sato, Masaaki

2012-01-01

Highlights: ► Nesprin-1 knockdown decreases widths of nuclei in ECs under static condition. ► Nuclear strain caused by stretching is increased by nesprin-1 knockdown in ECs. ► We model mechanical interactions of F-actin with the nucleus in stretched cells. ► F-actin bound to nesprin-1 may cause sustainable force transmission to the nucleus. -- Abstract: The linker of nucleus and cytoskeleton (LINC) complex, including nesprin-1, has been suggested to be crucial for many biological processes. Previous studies have shown that mutations in nesprin-1 cause abnormal cellular functions and diseases, possibly because of insufficient force transmission to the nucleus through actin filaments (F-actin) bound to nesprin-1. However, little is known regarding the mechanical interaction between the nucleus and F-actin through nesprin-1. In this study, we examined nuclear deformation behavior in nesprin-1 knocked-down endothelial cells (ECs) subjected to uniaxial stretching by evaluating nuclear strain from lateral cross-sectional images. The widths of nuclei in nesprin-1 knocked-down ECs were smaller than those in wild-type cells. In addition, nuclear strain in nesprin-1 knocked-down cells, which is considered to be compressed by the actin cortical layer, increased compared with that in wild-type cells under stretching condition. These results indicate that nesprin-1 knockdown releases the nucleus from the tension of F-actin bound to the nucleus, thereby increasing allowance for deformation before stretching, and that F-actin bound to the nucleus through nesprin-1 causes sustainable force transmission to the nucleus.

Penning-trap mass spectrometry of radioactive, highly charged ions. Measurements of neutron-rich Rb and Sr nuclides for nuclear astrophysics and development of a novel Penning trap for cooling highly charged ions

International Nuclear Information System (INIS)

Simon, Vanessa Veronique

2012-01-01

High-precision atomic mass measurements are vital for the description of nuclear structure, investigations of nuclear astrophysical processes, and tests of fundamental symmetries. The neutron-rich A ∼ 100 region presents challenges for modeling the astrophysical r-process because of sudden nuclear shape transitions. This thesis reports on high-precision masses of short-lived neutron-rich 94,97,98 Rb and 94,97-99 Sr isotopes using the TITAN Penning-trap mass spectrometer at TRIUMF. The isotopes were charge-bred to q = 15+; uncertainties of less than 4 keV were achieved. Results deviate by up to 11σ compared to earlier measurements and extend the region of nuclear deformation observed in the A∼100 region. A parameterized r-process model network calculation shows that mass uncertainties for the elemental abundances in this region are now negligible. Although beneficial for the measurement precision, the charge breeding process leads to an increased energy spread of the ions on the order of tens of eV/q. To eliminate this drawback, a Cooler Penning Trap (CPET) has been developed as part of this thesis. The novel multi-electrode trap structure of CPET forms nested potentials to cool HCI sympathetically using either electrons or protons to increase the overall efficiency and precision of the mass measurement. The status of the off-line setup and initial commissioning experiments are presented.

Q-deformed algebras and many-body physics

Energy Technology Data Exchange (ETDEWEB)

Galetti, D; Lunardi, J T; Pimentel, B M [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Lima, C L [Sao Paulo Univ., SP (Brazil). Inst. de Fisica

1995-11-01

A review is presented of some applications of q-deformed algebras to many-body systems. The rotational and pairing nuclear problems will be discussed in the context of q-deformed algebras, before presenting a more microscopically based application of q-deformed concepts to many-fermion systems. (author). 30 refs., 5 figs.

Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse - CSNSM/Centre for nuclear and mass spectroscopy, Activity Report 2002-2004

International Nuclear Information System (INIS)

2005-01-01

The Centre for nuclear and mass spectroscopy (CSNSM) is a CNRS (National Centre for Scientific Research) laboratory affiliated with Paris-Sud University. The CSNSM is involved in pluri-disciplinary activities covering various scientific domains: Nuclear Structure (SNO), Nuclear Astrophysics (AN), Solid State Astrophysics (AS), Solid State Physics (PS) and Chemical Physics of Irradiation. This document presents the activity of the Centre during the 2002-2004 years: 1 - Foreword; 2 - Nuclear structure; 3 - EFIX: study of exotic nuclei-induced fission; 4 - Nuclear Astrophysics; 5 - Atomic mass; 6 - Solid state astrophysics; 7 - Accelerator-based mass spectroscopy; 8 - Solid State Physics; 9 - Physics and Chemistry of Irradiation; 10 - Activities of general interest; 11 - SEMIRAMIS (ion source and ion beam handling); 12 - Computer Department; 13 - Electronics Group; 14 - Mechanics Department; 15 - Health and safety; 16 - Permanent training; 17 - Seminars; 18 - PhDs; 19 - Staff

Inelastic scattering of polarized protons and nuclear deformation in 16O, 18O

International Nuclear Information System (INIS)

de Swiniarski, R.; Pham, D.L.

1984-01-01

Many data concerning inelastic scattering of polarized protons at intermediate energy are now available. We have analyzed some of these data coming from LAMPF at 800 MeV for 16 O (6) and 18 O (7) in order to further study nuclear deformations for these light nuclei. Analyzing powers (A(theta)) and cross-sections ((σ/theta)) for elastic and inelastic scattering of 800 MeV polarized protons from 16 O and 18 O have been analyzed in the coupled-channels (CC) collective model using the code ECIS from Raynal

Mass-spectrometric measurements for nuclear safeguards

International Nuclear Information System (INIS)

Carter, J.A.; Smith, D.H.; Walker, R.L.

1982-01-01

The need of an on-site inspection device to provide isotopic ratio measurements led to the development of a quadrupole mass spectrometer mounted in a van. This mobile laboratory has the ability, through the use of the resin bead technique, to acquire, prepare, and analyze samples of interest to nuclear safeguards. Precision of the measurements is about 1 to 2%

Deformation mechanisms during nanoindentation of sodium borosilicate glasses of nuclear interest

Energy Technology Data Exchange (ETDEWEB)

Kilymis, D. A.; Delaye, J.-M., E-mail: jean-marc.delaye@cea.fr [CEA Marcoule, DEN/DTCD, Service d’Etude et Comportement des Matériaux de Conditionnement, BP17171 30207 Bagnols-sur-Cèze Cedex (France)

2014-07-07

In this paper we analyze results of Molecular Dynamics simulations of Vickers nanoindentation, performed for sodium borosilicate glasses of interest in the nuclear industry. Three glasses have been studied in their pristine form, as well as a disordered one that is analogous to the real irradiated glass. We focused in the behavior of the glass during the nanoindentation in order to reveal the mechanisms of deformation and how they are affected by microstructural characteristics. Results have shown a strong dependence on the SiO{sub 2} content of the glass, which promotes densification due to the open structure of SiO{sub 4} tetrahedra and also due to the strength of Si-O bonds. Densification for the glasses is primarily expressed by the relative decrease of the Si-O-Si and Si-O-B angles, indicating rotation of the structural units and decrease of free volume. The increase of alkali content on the other hand results to higher plasticity of the matrix and increased shear flow. The most important effect on the deformation mechanism of the disordered glasses is that of the highly depolymerized network that will also induce shear flow and, in combination with the increased free volume, will result in the decreased hardness of these glasses, as has been previously observed.

Deformation mechanisms during nanoindentation of sodium borosilicate glasses of nuclear interest.

Science.gov (United States)

Kilymis, D A; Delaye, J-M

2014-07-07

In this paper we analyze results of Molecular Dynamics simulations of Vickers nanoindentation, performed for sodium borosilicate glasses of interest in the nuclear industry. Three glasses have been studied in their pristine form, as well as a disordered one that is analogous to the real irradiated glass. We focused in the behavior of the glass during the nanoindentation in order to reveal the mechanisms of deformation and how they are affected by microstructural characteristics. Results have shown a strong dependence on the SiO2 content of the glass, which promotes densification due to the open structure of SiO4 tetrahedra and also due to the strength of Si-O bonds. Densification for the glasses is primarily expressed by the relative decrease of the Si-O-Si and Si-O-B angles, indicating rotation of the structural units and decrease of free volume. The increase of alkali content on the other hand results to higher plasticity of the matrix and increased shear flow. The most important effect on the deformation mechanism of the disordered glasses is that of the highly depolymerized network that will also induce shear flow and, in combination with the increased free volume, will result in the decreased hardness of these glasses, as has been previously observed.

UPDATED MASS SCALING RELATIONS FOR NUCLEAR STAR CLUSTERS AND A COMPARISON TO SUPERMASSIVE BLACK HOLES

International Nuclear Information System (INIS)

Scott, Nicholas; Graham, Alister W.

2013-01-01

We investigate whether or not nuclear star clusters and supermassive black holes (SMBHs) follow a common set of mass scaling relations with their host galaxy's properties, and hence can be considered to form a single class of central massive object (CMO). We have compiled a large sample of galaxies with measured nuclear star cluster masses and host galaxy properties from the literature and fit log-linear scaling relations. We find that nuclear star cluster mass, M NC , correlates most tightly with the host galaxy's velocity dispersion: log M NC = (2.11 ± 0.31)log (σ/54) + (6.63 ± 0.09), but has a slope dramatically shallower than the relation defined by SMBHs. We find that the nuclear star cluster mass relations involving host galaxy (and spheroid) luminosity and stellar and dynamical mass, intercept with but are in general shallower than the corresponding black hole scaling relations. In particular, M NC ∝M 0.55±0.15 Gal,dyn ; the nuclear cluster mass is not a constant fraction of its host galaxy or spheroid mass. We conclude that nuclear stellar clusters and SMBHs do not form a single family of CMOs.

Deformed potential energy of $^{263}Db$ in a generalized liquid drop model

CERN Document Server

Chen Bao Qiu; Zhao Yao Lin; 10.1088/0256-307X/20/11/009

2003-01-01

The macroscopic deformed potential energy for super-heavy nuclei /sup 263/Db, which governs the entrance and alpha decay channels, is determined within a generalized liquid drop model (GLDM). A quasi- molecular shape is assumed in the GLDM, which includes volume-, surface-, and Coulomb-energies, proximity effects, mass asymmetry, and an accurate nuclear radius. The microscopic single particle energies derived from a shell model in an axially deformed Woods- Saxon potential with a quasi-molecular shape. The shell correction is calculated by the Strutinsky method. The total deformed potential energy of a nucleus can be calculated by the macro-microscopic method as the summation of the liquid-drop energy and the Strutinsky shell correction. The theory is applied to predict the deformed potential energy of the experiment /sup 22/Ne+/sup 241/Am to /sup 263/Db* to /sup 259/Db+4 n, which was performed on the Heavy Ion Accelerator in Lanzhou. It is found that the neck in the quasi-molecular shape is responsible for t...

Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse - CSNSM/Centre for nuclear and mass spectroscopy, Activity Report 1985-1986-1987

International Nuclear Information System (INIS)

2003-01-01

The Centre for nuclear and mass spectroscopy (CSNSM) is a CNRS (National Centre for Scientific Research) laboratory affiliated with Paris-Sud University. The CSNSM is involved in pluri-disciplinary activities covering various scientific domains: Nuclear Structure (SNO), Nuclear Astrophysics (AN), Solid State Astrophysics (AS), Solid State Physics (PS) and Chemical Physics of Irradiation. This document presents the activity of the Centre during the 1985-1986-1987 years: 1 - Teams presentation; 2 - Abstracts: On the borderline of spectroscopy; Atomic spectroscopy and low-energy low-spin nuclear structure; high-energy high-spin nuclear structure; Theories and models; Nuclear astrophysics; Accelerator-based mass spectroscopy; Solid State Physics; Study of charged particles irradiation effects in astrophysics, geophysics and material sciences; Technical developments for the RF mass spectrometer and for Obelix; Technical developments for ion beams; Technical developments in electronics and their applications; CNSM's Computer Department; Developments in cryogenics; 3 - Staff and publications

Deformation dependent TUL multi-step direct model

International Nuclear Information System (INIS)

Wienke, H.; Capote, R.; Herman, M.; Sin, M.

2008-01-01

The Multi-Step Direct (MSD) module TRISTAN in the nuclear reaction code EMPIRE has been extended to account for nuclear deformation. The new formalism was tested in calculations of neutron emission spectra emitted from the 232 Th(n,xn) reaction. These calculations include vibration-rotational Coupled Channels (CC) for the inelastic scattering to low-lying collective levels, 'deformed' MSD with quadrupole deformation for inelastic scattering to the continuum, Multi-Step Compound (MSC) and Hauser-Feshbach with advanced treatment of the fission channel. Prompt fission neutrons were also calculated. The comparison with experimental data shows clear improvement over the 'spherical' MSD calculations and JEFF-3.1 and JENDL-3.3 evaluations. (authors)

Constraints on the nuclear equation of state from nuclear masses and radii in a Thomas-Fermi meta-modeling approach

Science.gov (United States)

Chatterjee, D.; Gulminelli, F.; Raduta, Ad. R.; Margueron, J.

2017-12-01

The question of correlations among empirical equation of state (EoS) parameters constrained by nuclear observables is addressed in a Thomas-Fermi meta-modeling approach. A recently proposed meta-modeling for the nuclear EoS in nuclear matter is augmented with a single finite size term to produce a minimal unified EoS functional able to describe the smooth part of the nuclear ground state properties. This meta-model can reproduce the predictions of a large variety of models, and interpolate continuously between them. An analytical approximation to the full Thomas-Fermi integrals is further proposed giving a fully analytical meta-model for nuclear masses. The parameter space is sampled and filtered through the constraint of nuclear mass reproduction with Bayesian statistical tools. We show that this simple analytical meta-modeling has a predictive power on masses, radii, and skins comparable to full Hartree-Fock or extended Thomas-Fermi calculations with realistic energy functionals. The covariance analysis on the posterior distribution shows that no physical correlation is present between the different EoS parameters. Concerning nuclear observables, a strong correlation between the slope of the symmetry energy and the neutron skin is observed, in agreement with previous studies.

Experimental deformation of a mafic rock - interplay between fracturing, reaction and viscous deformation

Science.gov (United States)

Marti, Sina; Stünitz, Holger; Heilbronner, Renée; Plümper, Oliver; Drury, Martyn

2016-04-01

Deformation experiments were performed on natural Maryland Diabase (˜ 55% Plg, 42% Px, 3% accessories, 0.18 wt.-% H2O added) in a Griggs-type deformation apparatus in order to explore the brittle-viscous transition and the interplay between deformation and mineral reactions. Shear experiments at strain rates of ˜ 2e-5 /s are performed, at T=600, 700 and 800°C and confining pressures Pc=1.0 and 1.5 GPa. Deformation localizes in all experiments. Below 700°C, the microstructure is dominated by brittle deformation with a foliation formed by cataclastic flow and high strain accommodated along 3-5 major ultracataclasite shear bands. At 700°C, the bulk of the material still exhibits abundant microfractures, however, deformation localizes into an anastomosing network of shear bands (SB) formed from a fine-grained (<< 1 μm) mixture of newly formed Plg and Amph. These reaction products occur almost exclusively along syn-kinematic structures such as fractures and SB. Experiments at 800°C show extensive mineral reactions, with the main reaction products Amph+Plg (+Zo). Deformation is localized in broad C' and C SB formed by a fine-grained (0.1 - 0.8 μm) mixture of Plg+Amph (+Zo). The onset of mineral reactions in the 700°C experiments shows that reaction kinetics and diffusional mass transport are fast enough to keep up with the short experimental timescales. While in the 700°C experiments brittle processes kinematically contribute to deformation, fracturing is largely absent at 800°C. Diffusive mass transfer dominates. The very small grain size within SB favours a grain size sensitive deformation mechanism. Due to the presence of water (and relatively high supported stresses), dissolution-precipitation creep is interpreted to be the dominant strain accommodating mechanism. From the change of Amph coronas around Px clasts with strain, we can determine that Amph is re-dissolved at high stress sites while growing in low stress sites, showing the ability of Amph to

Role of nesprin-1 in nuclear deformation in endothelial cells under static and uniaxial stretching conditions

Energy Technology Data Exchange (ETDEWEB)

Anno, Toshiro [Department of Biomedical Engineering, Graduate School of Biomedical Engineering, Tohoku University, Sendai (Japan); Sakamoto, Naoya, E-mail: sakan@me.kawasaki-m.ac.jp [Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, Sendai (Japan); Sato, Masaaki [Department of Biomedical Engineering, Graduate School of Biomedical Engineering, Tohoku University, Sendai (Japan)

2012-07-20

Highlights: Black-Right-Pointing-Pointer Nesprin-1 knockdown decreases widths of nuclei in ECs under static condition. Black-Right-Pointing-Pointer Nuclear strain caused by stretching is increased by nesprin-1 knockdown in ECs. Black-Right-Pointing-Pointer We model mechanical interactions of F-actin with the nucleus in stretched cells. Black-Right-Pointing-Pointer F-actin bound to nesprin-1 may cause sustainable force transmission to the nucleus. -- Abstract: The linker of nucleus and cytoskeleton (LINC) complex, including nesprin-1, has been suggested to be crucial for many biological processes. Previous studies have shown that mutations in nesprin-1 cause abnormal cellular functions and diseases, possibly because of insufficient force transmission to the nucleus through actin filaments (F-actin) bound to nesprin-1. However, little is known regarding the mechanical interaction between the nucleus and F-actin through nesprin-1. In this study, we examined nuclear deformation behavior in nesprin-1 knocked-down endothelial cells (ECs) subjected to uniaxial stretching by evaluating nuclear strain from lateral cross-sectional images. The widths of nuclei in nesprin-1 knocked-down ECs were smaller than those in wild-type cells. In addition, nuclear strain in nesprin-1 knocked-down cells, which is considered to be compressed by the actin cortical layer, increased compared with that in wild-type cells under stretching condition. These results indicate that nesprin-1 knockdown releases the nucleus from the tension of F-actin bound to the nucleus, thereby increasing allowance for deformation before stretching, and that F-actin bound to the nucleus through nesprin-1 causes sustainable force transmission to the nucleus.

Ground state properties of exotic nuclei in deformed medium mass region

International Nuclear Information System (INIS)

Manju; Chatterjee, R.; Singh, Jagjit; Shubhchintak

2017-01-01

The dipole moment, size of the nucleus and other ground state properties of deformed nuclei 37 Mg and 31 Ne are presented. Furthermore with this deformed wave function the electric dipole strength distribution for deformed nuclei 37 Mg and 31 Ne is calculated. This will allow us to investigate the two dimensional scaling phenomenon with two parameters: quadrupole deformation and separation energy

Deformations of spacetime and internal symmetries

Directory of Open Access Journals (Sweden)

Gresnigt Niels G.

2017-01-01

Full Text Available Algebraic deformations provide a systematic approach to generalizing the symmetries of a physical theory through the introduction of new fundamental constants. The applications of deformations of Lie algebras and Hopf algebras to both spacetime and internal symmetries are discussed. As a specific example we demonstrate how deforming the classical flavor group S U(3 to the quantum group S Uq(3 ≡ U q (su(3 (a Hopf algebra and taking into account electromagnetic mass splitting within isospin multiplets leads to new and exceptionally accurate baryon mass sum rules that agree perfectly with experimental data.

Improved Nuclear Reactor and Shield Mass Model for Space Applications

Science.gov (United States)

Robb, Kevin

2004-01-01

New technologies are being developed to explore the distant reaches of the solar system. Beyond Mars, solar energy is inadequate to power advanced scientific instruments. One technology that can meet the energy requirements is the space nuclear reactor. The nuclear reactor is used as a heat source for which a heat-to-electricity conversion system is needed. Examples of such conversion systems are the Brayton, Rankine, and Stirling cycles. Since launch cost is proportional to the amount of mass to lift, mass is always a concern in designing spacecraft. Estimations of system masses are an important part in determining the feasibility of a design. I worked under Michael Barrett in the Thermal Energy Conversion Branch of the Power & Electric Propulsion Division. An in-house Closed Cycle Engine Program (CCEP) is used for the design and performance analysis of closed-Brayton-cycle energy conversion systems for space applications. This program also calculates the system mass including the heat source. CCEP uses the subroutine RSMASS, which has been updated to RSMASS-D, to estimate the mass of the reactor. RSMASS was developed in 1986 at Sandia National Laboratories to quickly estimate the mass of multi-megawatt nuclear reactors for space applications. In response to an emphasis for lower power reactors, RSMASS-D was developed in 1997 and is based off of the SP-100 liquid metal cooled reactor. The subroutine calculates the mass of reactor components such as the safety systems, instrumentation and control, radiation shield, structure, reflector, and core. The major improvements in RSMASS-D are that it uses higher fidelity calculations, is easier to use, and automatically optimizes the systems mass. RSMASS-D is accurate within 15% of actual data while RSMASS is only accurate within 50%. My goal this summer was to learn FORTRAN 77 programming language and update the CCEP program with the RSMASS-D model.

Nuclear mass formulas and its application for astrophysics

International Nuclear Information System (INIS)

Koura, Hiroyuki

2003-01-01

Some nuclear mass formulae are reviewed and applied for the calculation of the rapid neutron-capture-process (r-process) nucleosynthesis. A new mass formula composed of the gross term, the even-odd term, and the shell term is also presented. The new mass formula is a revised version of the spherical basis mass formula published in 2001, that is, the even-odd term is treated more carefully, and a considerable improvement is brought about. The root-mean-square deviation of the new formula from experimental masses is 641 keV for Z ≥ 8 and N ≥ 8. Properties on systematic of the neutron-separation energy is compared with some mass formulas. The calculated abundances of the r-process from different mass formulae are compared with use of a simple reaction model, and the relation between the calculated abundances and the corresponding masses are discussed. Furthermore, fission barriers for the superheavy and neutron-rich nuclei are also applied for the endpoint of the r-process. (author)

Thomas-Fermi approach to nuclear mass formula. Pt. 1

International Nuclear Information System (INIS)

Dutta, A.K.; Arcoragi, J.P.; Pearson, J.M.; Tondeur, F.

1986-01-01

With a view to having a more secure basis for the nuclear mass formula than is provided by the drop(let) model, we make a preliminary study of the possibilities offered by the Skyrme-ETF method. Two ways of incorporating shell effects are considered: the ''Strutinsky-integral'' method of Chu et al., and the ''expectation-value'' method of Brack et al. Each of these methods is compared with the HF method in an attempt to see how reliably they extrapolate from the known region of the nuclear chart out to the neutron-drip line. The Strutinsky-integral method is shown to perform particularly well, and to offer a promising approach to a more reliable mass formula. (orig.)

Numerical simulation of the time-dependent deformation behaviour of clay-stone rock mass at the Tournemire site with 2D and 3D models

International Nuclear Information System (INIS)

Rutenberg, M.; Lux, K. H.

2011-01-01

Clay-stone rock masses are a reasonable alternative to e.g. salt rock masses as a host rock for underground radioactive waste repositories because of their very low permeability as well as their radionuclide retention capacity. Though clay-stone has been explored for many years, there is still a need for further research on its hydro-mechanical behaviour. Convergence measurements over a 4-year period in the tunnel system of the argillaceous Tournemire site in France yielded the presence of a time-dependent deformation behaviour in indurated clay. Moreover, a mine-by test was carried out with extensometer measurements capturing the rock mass deformation during the excavation process of a new gallery in 2003.This work focuses on the validation of a constitutive model by means of a three-dimensional (3D) simulation of the mine-by test. The utilised constitutive model Hou/Lux-T is based on the viscous constitutive model Lubby2 with which time-dependent deformation behaviour of salt rock can appropriately be simulated. It has been adapted to clay-stone by considering anisotropy effects, and in addition it features a strain-dependent fracture and failure criterion. The results of the mine-by-test simulation show that the calculated stresses and deformations in the rock mass seem to behave reasonably under this constitutive model with respect to time-dependency. A comparison of the 3D results to the results of a simplified two-dimensional (2D) simulation confirms the adequacy of using a 2D model with the constitutive model Hou/Lux-T for the setting at hand, described in the text (material parameters, time scale), in order to assess load-bearing capacity and deformability of the gallery near field away from heading face and tunnel crossing. Finally, a comparison of the 3D simulation results to the extensometer measurement results yields the principal ability of the used constitutive model to describe time-dependent evolutions of stresses and deformations during a three

Is nucleon deformed?

International Nuclear Information System (INIS)

Abbas, Afsar

1992-01-01

The surprising answer to this question Is nucleon deformed? is : Yes. The evidence comes from a study of the quark model of the single nucleon and when it is found in a nucleus. It turns out that many of the long standing problems of the Naive Quark Model are taken care of if the nucleon is assumed to be deformed. Only one value of the parameter P D ∼1/4 (which specifies deformation) fits g A (the axial vector coupling constant) for all the semileptonic decay of baryons, the F/D ratio, the pion-nucleon-delta coupling constant fsub(πNΔ), the double delta coupling constant 1 fsub(πΔΔ), the Ml transition moment μΔN and g 1 p the spin structure function of proton 2 . All this gives strong hint that both neutron and proton are deformed. It is important to look for further signatures of this deformation. When this deformed nucleon finds itself in a nuclear medium its deformation decreases. So much that in a heavy nucleus the nucleons are actually spherical. We look into the Gamow-Teller strengths, magnetic moments and magnetic transition strengths in nuclei to study this property. (author). 15 refs

Applications of accelerator mass spectrometry to nuclear physics and astrophysics

International Nuclear Information System (INIS)

Guo Zhiyu; Zhang Chuan

2002-01-01

As an ultra high sensitive analyzing method, accelerator mass spectrometry is playing an important role in the studies of nuclear physics and astrophysics. The accelerator mass spectrometry (AMS) applications in searching for violation of Pauli exclusion principle and study on supernovae are discussed as examples

DEFORMATION DEPENDENT TUL MULTI-STEP DIRECT MODEL

International Nuclear Information System (INIS)

WIENKE, H.; CAPOTE, R.; HERMAN, M.; SIN, M.

2007-01-01

The Multi-Step Direct (MSD) module TRISTAN in the nuclear reaction code EMPIRE has been extended in order to account for nuclear deformation. The new formalism was tested in calculations of neutron emission spectra emitted from the 232 Th(n,xn) reaction. These calculations include vibration-rotational Coupled Channels (CC) for the inelastic scattering to low-lying collective levels, ''deformed'' MSD with quadrupole deformation for inelastic scattering to the continuum, Multi-Step Compound (MSC) and Hauser-Feshbach with advanced treatment of the fission channel. Prompt fission neutrons were also calculated. The comparison with experimental data shows clear improvement over the ''spherical'' MSD calculations and JEFF-3.1 and JENDL-3.3 evaluations

From chemical mapping to pressure temperature deformation micro-cartography: mineralogical evolution and mass transport in thermo-mechanic disequilibrium systems: application to meta-pelites and confinement nuclear waste materials

International Nuclear Information System (INIS)

Andrade, V. de

2006-03-01

The mineralogical composition of metamorphic rocks or industrial materials evolves when they are submitted to thermomechanical disequilibria, i.e. a spatial or temporal pressure and temperature evolution, or chemical disequilibria as variations in redox conditions, pH... For example, during low temperature metamorphic processes, rocks re-equilibrate only partially, and thus record locally thermodynamic equilibria increasing so the spatial chemical heterogeneities. Understanding the P-T evolution of such systems and deciphering modalities of their mineralogical transformation imply to recognize and characterize the size of these local 'paleo-equilibria', and so to have a spatial chemical information at least in 2 dimensions. In order to get this information, microprobe X-ray fluorescence maps have been used. Computer codes have been developed with Matlab to quantify these maps in view of thermo-barometric estimations. In this way, P-T maps of mineral crystallisation were produced using the multi-equilibria thermodynamic technique. Applications on two meta-pelites from the Sambagawa blue-schist belt (Japan) and from the Caledonian eclogitic zone in Spitsbergen, show that quantitative chemical maps are a powerful tool to retrieve the metamorphic history of rocks. From these chemical maps have been derived maps of P-T-time-redox-deformation that allow to characterize P-T conditions of minerals formation, and so, the P-T path of the sample, the oxidation state of iron in the chlorite phase. As a result, we underline the relation between deformation and crystallisation, and propose a relative chronology of minerals crystallisation and deformations. The Fe 3+ content map in chlorite calculated by thermodynamic has also been validated by a μ-XANES mapping at the iron K-edge measured at the ESRF (ID24) using an innovative method. Another application relates to an experimental study of clay materials, main components of an analogical model of a nuclear waste storage site

Equidistant structure and effective nucleon mass in nuclear matter

International Nuclear Information System (INIS)

Tezuka, Hirokazu.

1981-11-01

The effective nucleon mass of the Equidistant Multi-Layer Structure (EMULS) is discussed self-consistently. In the density region where the Fermi gas state in nuclear matter is unstable against the density fluctuation, the EMULS gives lower binding energy. It is, however, shown that such a structure with an ordinary nucleon mass collapses due to too strong attraction. We point out that such a collapse can be avoided by taking account of an effective nucleon mass affected by the localization of nucleons. (author)

Super rigid nature of super-deformed bands

International Nuclear Information System (INIS)

Sharma, Neha; Mittal, H.M.; Jain, A.K.

2012-01-01

The phenomenon of high-spin super-deformation represents one of the most remarkable discoveries in nuclear physics. A large number of SD bands have been observed in A = 60, 80, 130, 150, 190 mass regions. The cascades of SD bands are known to be connected by electric quadruple E2 transitions. Because of absence of linking transitions between superdeformed (SD) and normal deformed (ND) levels, the spin assignments of most of these bands carry a minimum uncertainty ≈ 1-2ħ. It was found in an analysis of SD bands in the context of semi classical approach that moment of inertia comes close to the rigid body value in most of the cases. Lack of knowledge of spins has led to an emphasis on the study of dynamical moment of inertia of SD bands and systematic of kinematic moment of inertia has not been examined so far. In this paper, we extract the band moment of inertia J 0 and softness parameter (σ) of all the SD bands corresponding to axes ratio (x) = 1.5 and present their systematic

The nuclear deformation versus spin-flip like excitations and the suppression of the 2νββ amplitude

International Nuclear Information System (INIS)

Raduta, A.A.; Delion, D.S.; Faessler, Amand

1997-01-01

We were the first who investigated the influence of spin-flip and non-spin-flip configuration on the separation of the transition amplitude of the Gamow-Teller double beta decay. A realistic Hamiltonian and a projected spherical single particle basis is considered, while the effects are generated by three antagonistic sources: spin-flip, non-spin-flip like excitation and nuclear deformation. Moreover, by a smooth variation of a deformation parameter one could bridge the spherical and deformed pictures. Although our application is not aimed at describing the experimental situation we chose as input data those corresponding to the transition 82 Se → 82 Kr. For near spherical case there are two resonances in M GT , one having a spin-flip structure and identified as GT resonance and one of non-spin-flip structure, placed at low energy. For large deformation and vanishing g pp coupling constant there are two resonances of spin-flip and non-spin-flip natures (ΔI = 1 and 0, respectively) and located at the same energy, what indicates that the deformation acts against the separation of this resonances. In conclusion, our calculation showed that the mechanism of M GT suppression is different for spherical and deformed nuclei. In both cases approaching the critical value of g pp where the RPA breaks down, a lot of strength is accumulated in lowest RPA state and, while in the spherical case this has a non spin-flip nature, in the deformed case the state is a mixture of both types of configurations

Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse - CSNSM/Centre for nuclear and mass spectroscopy, Activity Report 1992-1994

International Nuclear Information System (INIS)

2003-01-01

The Centre for nuclear and mass spectroscopy (CSNSM) is a CNRS (National Centre for Scientific Research) laboratory affiliated with Paris-Sud University. The CSNSM is involved in pluri-disciplinary activities covering various scientific domains: Nuclear Structure (SNO), Nuclear Astrophysics (AN), Solid State Astrophysics (AS), Solid State Physics (PS) and Chemical Physics of Irradiation. This document presents the activity of the Centre during the 1992-1994 years: 1 - Nuclear structure; 2 - Nuclear astrophysics; 3 - Basic symmetries; 4 - Accelerator-based mass spectroscopy; 5 - Solid State Astrophysics; 6 - Physics and Chemistry of Irradiation; 7 - Solid State Physics; 8 - SEMIRAMIS (ion source and ion beam handling); 9 - Computer Department; 10 - Electronics Group; 11 - Mechanics Department; 12 - Permanent training; 13 - Health and safety; 14 - Seminars; 15 - Dissertations; 16 - Publications; 17 - Staff

The nuclear waste issue in Swedish mass media

International Nuclear Information System (INIS)

Hedberg, P.

1991-04-01

This is an investigation of the representation given in the Swedish mass media of questions concerning the nuclear waste. The investigation covers the period from 1979 to 1989 of 8 newspapers of different political colours and the Swedish radio and television. (KAE)

The role of nuclear shapes in nuclear structure (from the perspective of the Daresbury Tandem)

International Nuclear Information System (INIS)

Nazarewicz, W.

1993-01-01

In specific regions of the nuclear periodic chart, large multipole moments are observed and the low-lying excitations have a rotational character. These features are understood if the nuclei in question are assumed to have a stable deformation, i.e., a non-spherical distribution of the nuclear matter. In other (transitional) regions the quasi-rotational bands are present; they are strongly coupled to low-lying vibrational modes. Those nuclei are best understood in terms of small static deformations but large dynamic fluctuations around local equilibria. As a matter of fact, the vast majority of nuclei are deformed; even in those which are spherical or almost spherical, the dynamical couplings to shape vibrations are crucial. The issue of nuclear deformation is many-faceted. If the nuclear shape (nuclear mean field) is deformed, characteristic excitation modes are present, such as rotations and vibrations built upon the non-spherical equilibrium. Through the particle-core coupling, nuclear deformations can dramatically influence the single-particle properties of nucleons moving in the average nuclear potential. Many experimental investigations using the Daresbury Tandem were related in one way or another to the physics of nuclear shapes. Fundamental discoveries from Daresbury include the observation of superdeformed structures in rapidly rotating nuclei, the observation of identical (open-quotes twinnedclose quotes) rotational bands, various studies of structural changes induced by very fast rotation (band-crossings, band-terminations), the observation of the oblate-deformed open-quotes dipoleclose quotes bands, studies of reflection-asymmetric shapes, studies of (quasimolecular) cluster configurations in light nuclei, and many, many others. The author reviews the forefront research at Daresbury from the global perspective; the common denominator being the nuclear shape deformation

Neutron halo in deformed nuclei

International Nuclear Information System (INIS)

Zhou Shangui; Meng Jie; Ring, P.; Zhao Enguang

2010-01-01

Halo phenomena in deformed nuclei are investigated within a deformed relativistic Hartree Bogoliubov (DRHB) theory. These weakly bound quantum systems present interesting examples for the study of the interdependence between the deformation of the core and the particles in the halo. Contributions of the halo, deformation effects, and large spatial extensions of these systems are described in a fully self-consistent way by the DRHB equations in a spherical Woods-Saxon basis with the proper asymptotic behavior at a large distance from the nuclear center. Magnesium and neon isotopes are studied and detailed results are presented for the deformed neutron-rich and weakly bound nucleus 44 Mg. The core of this nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the occurrence of this decoupling effects are discussed.

Relativistic mean-field approximation with density-dependent screening meson masses in nuclear matter

International Nuclear Information System (INIS)

Sun, Baoxi; Lu, Xiaofu; Shen, Pengnian; Zhao, Enguang

2003-01-01

The Debye screening masses of the σ, ω and neutral ρ mesons and the photon are calculated in the relativistic mean-field approximation. As the density of the nucleon increases, all the screening masses of mesons increase. A different result with Brown–Rho scaling is shown, which implies a reduction in the mass of all the mesons in the nuclear matter, except the pion. Replacing the masses of the mesons with their corresponding screening masses in the Walecka-1 model, five saturation properties of the nuclear matter are fixed reasonably, and then a density-dependent relativistic mean-field model is proposed without introducing the nonlinear self-coupling terms of mesons. (author)

Electron form factors of deformable nuclei

International Nuclear Information System (INIS)

Tartakovskii, V.K.; Isupov, V.Yu.

1988-01-01

Using the smallness of the deformation parameter of the nucleus, we obtain simple explicit expressions for the form factors of electroexcitation of the low-lying rotation-vibration states of light, deformable, even-even nuclei. The expressions satisfactorily describe the experimental data on the excitation of collective nuclear states by the inelastic scattering of fast electrons

Characteristic relation for the mass and energy distribution of the nuclear fission products

International Nuclear Information System (INIS)

Alexandru, G.

1977-01-01

The dispersion relation for nuclear fission is written in the two part fragmentation approach which allows to obtain the characteristic relation for the mass and energy distribution of the nuclear fission products. One explains the resonance approximation in the mass distribution of the fission products taking into account the high order resonances too. (author)

Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse - CSNSM/Centre for nuclear and mass spectroscopy, Activity Report 2001-2002

International Nuclear Information System (INIS)

2003-01-01

The Centre for nuclear and mass spectroscopy (CSNSM) is a CNRS (National Centre for Scientific Research) laboratory affiliated with Paris-Sud University. The CSNSM is involved in pluri-disciplinary activities covering various scientific domains: Nuclear Structure (SNO), Nuclear Astrophysics (AN), Solid State Astrophysics (AS), Solid State Physics (PS) and Chemical Physics of Irradiation. This document presents the activity of the Centre during the 2001-2002 years: 1 - Foreword; 2 - Research topics: Nuclear structure; EFIX: study of exotic nuclei-induced fission; Nuclear Astrophysics; Accelerator-based mass spectroscopy; Solid State Astrophysics; Physics and Chemistry of Irradiation; Solid State Physics; SEMIRAMIS (ion source and ion beam handling); Digest science; 3 - Publications; 4 - Dissertations; 5 - Seminars; 6 - Technical services: Computer Department; Electronics Group; Mechanics Department; Permanent training; Health and safety; 7 - Staff

Deformation effects in the cluster radioactivity

International Nuclear Information System (INIS)

Misicu, S.; Protopopescu, D.

1998-01-01

We investigate the influence of the deformation on the decay rates of the cluster emission process 224 Ra → 210 Pb + 14 C. The interaction between the daughter and the cluster is given by a double folding potential, containing a nuclear repulsive core, with account of the quadrupole and hexadecupole deformed densities of both fragments. Upon comparison with the experimental value of the decay rate, the results obtained point out the importance of such deformations especially for the daughter nucleus

Nucleon deformation from lattice QCD

International Nuclear Information System (INIS)

Tsapalis, A.

2008-01-01

The issue of nucleon and Delta(1232) deformation is discussed through the evaluation of the N to Delta electromagnetic transition and Delta electromagnetic form factors in Lattice QCD. The momentum dependence of the form factors is studied using 2+1 staggered dynamical flavors at pion masses as low as 350 MeV and compared to results obtained in the Wilson quenched and two-flavor dynamical theory at similar pion masses. The measurement of small non-zero quadrupole amplitudes, in agreement to recent experiments, establishes the existence of deformation in the N and Delta states. (author)

RSMASS-D nuclear thermal propulsion and bimodal system mass models

Science.gov (United States)

King, Donald B.; Marshall, Albert C.

1997-01-01

Two relatively simple models have been developed to estimate reactor, radiation shield, and balance of system masses for a particle bed reactor (PBR) nuclear thermal propulsion concept and a cermet-core power and propulsion (bimodal) concept. The approach was based on the methodology developed for the RSMASS-D models. The RSMASS-D approach for the reactor and shield sub-systems uses a combination of simple equations derived from reactor physics and other fundamental considerations along with tabulations of data from more detailed neutron and gamma transport theory computations. Relatively simple models are used to estimate the masses of other subsystem components of the nuclear propulsion and bimodal systems. Other subsystem components include instrumentation and control (I&C), boom, safety systems, radiator, thermoelectrics, heat pipes, and nozzle. The user of these models can vary basic design parameters within an allowed range to achieve a parameter choice which yields a minimum mass for the operational conditions of interest. Estimated system masses are presented for a range of reactor power levels for propulsion for the PBR propulsion concept and for both electrical power and propulsion for the cermet-core bimodal concept. The estimated reactor system masses agree with mass predictions from detailed calculations with xx percent for both models.

Nuclear molecular structure in heavy mass systems

International Nuclear Information System (INIS)

Arctaedius, T.; Bargholtz, C.

1989-04-01

A study is made of nuclear molecular configurations involving one heavy mass partner. The stability of these configurations to mass flow and to fission is investigated as well as their population in fusion reactions. It is concluded that shell effects in combination with the effects of angular momentum may be important in stabilizing certain configurations. A possible relation of these configurations to the so called superdeformed states is pointed out. The spectrum of rotational and vibrational trasitions within molecular configurations is investigated. For sufficiently mass-asymmetric systems the engergies of vibrational transitions are comparable to the neutron separation energy. Gamma radiation from such transitions may then be observable above the background of statistical transitions. The gamma spectrum and the directional distribution of the radioation following fusion reactions with 12 C and 16 O are calculated. (authors)

Mass shift of σ-meson in nuclear matter

International Nuclear Information System (INIS)

Morones-Ibarra, J.R.; Maciel, Mónica Menchaca; Padilla, Felipe Robledo; Santos-Guevara, Ayax

2013-01-01

The propagation of σ-meson in nuclear matter is studied in the Walecka model, by assuming that sigma couples to a pair of nucleon-antinucleon states to particle-hole states. The in-medium effect of σ-ω mixing is also studied. For completeness, the coupling of sigma to two virtual pions was also considered. It is found that the σ-meson mass decreases with respect to its value in vacuum and that the contribution of the σ-ω mixing effect on the mass shift is relatively small. (author)

[Nuclear theory

International Nuclear Information System (INIS)

Haxton, W.

1990-01-01

This report discusses research in nuclear physics. Topics covered in this paper are: symmetry principles; nuclear astrophysics; nuclear structure; quark-gluon plasma; quantum chromodynamics; symmetry breaking; nuclear deformation; and cold fusion

On the deformed Einstein equations and quantum black holes

International Nuclear Information System (INIS)

Dil, E; Ersanli, C C; Kolay, E

2016-01-01

Recently q -deformed Einstein equations have been studied for extremal quantum black holes which have been proposed to obey deformed statistics by Strominger. In this study, we give the solutions of deformed Einstein equations by considering these equations for the charged black holes. Also we present the implications of the solutions, such as the deformation parameters lead the charged black holes to have a smaller mass than the classical Reissner- Nordstrom black holes. The reduction in mass of a classical black hole can be viewed as a transition from classical to quantum black hole regime. (paper)

A coupled theory for chemically active and deformable solids with mass diffusion and heat conduction

Science.gov (United States)

Zhang, Xiaolong; Zhong, Zheng

2017-10-01

To analyse the frequently encountered thermo-chemo-mechanical problems in chemically active material applications, we develop a thermodynamically-consistent continuum theory of coupled deformation, mass diffusion, heat conduction and chemical reaction. Basic balance equations of force, mass and energy are presented at first, and then fully coupled constitutive laws interpreting multi-field interactions and evolving equations governing irreversible fluxes are constructed according to the energy dissipation inequality and the chemical kinetics. To consider the essential distinction between mass diffusion and chemical reactions in affecting free energy and dissipations of a highly coupled system, we regard both the concentrations of diffusive species and the extent of reaction as independent state variables. This new formulation then distinguishes between the energy contribution from the diffusive species entering the solid and that from the subsequent chemical reactions occurring among these species and the host solid, which not only interact with stresses or strains in different manners and on different time scales, but also induce different variations of solid microstructures and material properties. Taking advantage of this new description, we further establish a specialized isothermal model to predict precisely the transient chemo-mechanical response of a swelling solid with a proposed volumetric constraint that accounts for material incompressibility. Coupled kinetics is incorporated to capture the volumetric swelling of the solid caused by imbibition of external species and the simultaneous dilation arised from chemical reactions between the diffusing species and the solid. The model is then exemplified with two numerical examples of transient swelling accompanied by chemical reaction. Various ratios of characteristic times of diffusion and chemical reaction are taken into account to shed light on the dependency on kinetic time scales of evolution patterns for

Role of mass spectrometry in nuclear forensic science

International Nuclear Information System (INIS)

Joseph, M.; Sivaraman, N.

2016-01-01

The present talk will focus on the role of mass spectrometry in NFS in general; besides that, the various chromatographic methods developed towards separation of actinides and lanthanide fission products and characterization of dissolver solutions of nuclear reactor fuels using TIMS and some applications of using ICP-MS as well

Shape transition in Pt-nuclei with mass A ∼190

International Nuclear Information System (INIS)

Chamoli, S.K.

2017-01-01

The nuclei in mass region A ∼190 are well known for the prolate-oblate shape co-existence/transition phenomena. The shape coexistence phenomena has been observed in nuclei like Hg and Tl of this mass region. The calculations done for Pt nuclei in indicate a smooth shape change from prolate deformed "1"8"6Pt to nearly spherical "2"0"2"-"2"0"4 Pt through the region of triaxially deformed "1"8"8"-"1"9"8Pt and slightly oblate "2"0"0Pt. In these calculations, a change of shape from prolate to oblate is expected at A = 188. In recent high spin spectroscopic investigations, significant amount of reduced prolate collectivity has been observed in "1"8"8Pt. The level lifetimes provide valuable information about the nuclear shape and also the shape change with increase in spin along a band. So, to get clear signature of prolate to oblate shape inversion in Pt nuclei near A = 190, it is required to perform lifetime measurements. With this objective, the RDM lifetime measurements of high spin states have been done for various even-even Pt isotopes with masss A ≤ 186 over the years. The results obtained in these measurements are very encouraging and do indicate changing nuclear structure for Pt-isotopes with increasing mass at low spins. A gradual increase in B(E2) values upto 4"+ state and near constant nature there after in "1"8"8Pt, contrary to the other light neighboring Pt nuclei tends to indicate the volatile nature of deformation in Pt nuclei near A ∼ 190 which needs further theoretical investigations. (author)

Where is the Scissors Mode Strength in Odd-Mass Nuclei?

International Nuclear Information System (INIS)

Enders, J.; Huxel, N.; von Neumann-Cosel, P.; Richter, A.

1997-01-01

It is demonstrated by a fluctuation analysis based on the assumption of a Wigner distribution for the nuclear level spacings and of a Porter-Thomas distribution for the transition strengths that significant parts of the dipole strength excited in photon scattering experiments in heavy, deformed odd-mass nuclei are hidden in the background of the experimental spectra. With this additional strength, the heretofore claimed severe reduction of the B(M1) scissors mode strength in odd-mass nuclei compared to the one in neighboring even-even nuclei disappears. copyright 1997 The American Physical Society

Investigation into iron moessbauer atom state in a deformed iron-manganese alloys

International Nuclear Information System (INIS)

Mints, R.I.; Semenkin, V.A.; Shevchenko, Yu.A.

1977-01-01

A plastically deformed Fe + 12 at. %. Mn alloy was investigated by the method of nuclear gamma-resonance on Fe 57 nuclei. The specimens were deformed by 5 to 57 %. The obtained nuclear gamma-resonance spectra, which are a superposition of the paramagnetic single line (ν-phase) and the Zeeman splitting line (α-phase), were statistically processed with the aid of a computer. The behaviour of the values of Moessbauer parameters possessing a least dispersion, such as isomer chemical shift, quadrupolar reaction constant, effectiveness of magnetic field and of area of the nuclear gamma-resonance spectrum, points to their connection with the degree of the deformation disintegration of the initial solid solution

Solution of Deformed Einstein Equations and Quantum Black Holes

International Nuclear Information System (INIS)

Dil, Emre; Kolay, Erdinç

2016-01-01

Recently, one- and two-parameter deformed Einstein equations have been studied for extremal quantum black holes which have been proposed to obey deformed statistics by Strominger. In this study, we give a deeper insight into the deformed Einstein equations and consider the solutions of these equations for the extremal quantum black holes. We then represent the implications of the solutions, such that the deformation parameters lead the charged black holes to have a smaller mass than the usual Reissner-Nordström black holes. This reduction in mass of a usual black hole can be considered as a transition from classical to quantum black hole regime.

Splitting of ISGMR strength in the light-mass nucleus 24Mg due to ground-state deformation

Directory of Open Access Journals (Sweden)

Y.K. Gupta

2015-09-01

Full Text Available The isoscalar giant monopole resonance (ISGMR strength distribution in 24Mg has been determined from background-free inelastic scattering of 386-MeV α particles at extreme forward angles, including 0∘. The ISGMR strength distribution has been observed for the first time to have a two-peak structure in a light-mass nucleus. This splitting of ISGMR strength is explained well by microscopic theory in terms of the prolate deformation of the ground state of 24Mg.

Nuclear structure studies of neutron-rich heavy nuclei by mass measurements of francium and radium isotopes

Energy Technology Data Exchange (ETDEWEB)

Rosenbusch, Marco [Ernst-Moritz-Arndt-Universitaet, Institut fuer Physik, 17487 Greifswald (Germany); Collaboration: ISOLTRAP-Collaboration

2013-07-01

The mass is a unique property of an atomic nucleus reflecting its binding energy and thus the sum of all interactions at work. Precise measurements of nuclear masses especially of short-lived exotic nuclides provide important input for nuclear structure, nuclear astrophysics, tests of the Standard Model, and weak interaction studies. The Penning-trap mass spectrometer ISOLTRAP at the on-line isotope separator ISOLDE/CERN has been set up for precision mass measurements and continuously improved for accessing more exotic nuclides. The mass uncertainty is typically δm / m=10{sup -8} and the accessible half-life has been reduced to about 50 ms. In this contribution, the results of a measurement campaign of neutron-rich francium and radium isotopes will be presented, i.e. the masses of the isotopic chain of {sup 224-233}Fr and {sup 233,234}Ra, one of the most neutron-rich ensemble obtainable at ISOL facilities. The mass {sup 234}Ra denotes the heaviest mass ever measured with ISOLTRAP. Experimental data in the neutron-rich, heavy mass region is of great interest for studies of structural evolution far from stability, especially because the knowledge from nuclear mass models is scarce. The impact of the new data on the physics in this mass region as well as recent technical developments of ISOLTRAP are discussed.

Single particle Schroedinger fluid and moments of inertia of deformed nuclei

International Nuclear Information System (INIS)

Doma, S.B.

2002-01-01

The authors have applied the theory of the single-particle Schroedinger fluid to the nuclear collective motion of axially deformed nuclei. A counter example of an arbitrary number of independent nucleons in the anisotropic harmonic oscillator potential at the equilibrium deformation has been also given. Moreover, the ground states of the doubly even nuclei in the s-d shell 20 Ne, 24 Mg, 28 Si, 32 S and 36 Ar are constructed by filling the single-particle states corresponding to the possible values of the number of quanta of excitations n x , n y and n z . Accordingly, the cranking-model, the rigid-body model and the equilibrium-model moments of inertia of these nuclei are calculated as functions of the oscillator parameters ℎω x , ℎω y and ℎω z which are given in terms of the non deformed value ℎω 0 0 , depending on the mass number A, the number of neutrons N, the number of protons Z, and the deformation parameter β. The calculated values of the cranking-model moments of inertia of these nuclei are in good agreement with the corresponding experiential values and show that the considered axially deformed nuclei may have oblate as well as prolate shapes and that the nucleus 24 Mg is the only one which is highly deformed. The rigid-body model and the equilibrium-model moments of inertia of the two nuclei 20 Ne and 24 Mg are also in good agreement with the corresponding experimental values

Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse - CSNSM/Centre for nuclear and mass spectroscopy, Activity Report 1995-1997

International Nuclear Information System (INIS)

2003-01-01

The Centre for nuclear and mass spectroscopy (CSNSM) is a CNRS (National Centre for Scientific Research) laboratory affiliated with Paris-Sud University. The CSNSM is involved in pluri-disciplinary activities covering various scientific domains: Nuclear Structure (SNO), Nuclear Astrophysics (AN), Solid State Astrophysics (AS), Solid State Physics (PS) and Chemical Physics of Irradiation. This document presents the activity of the Centre during the 1995-1997 years: 1 - Nuclear structure: structure of first well states, superdeformation, high-spin state populations of stable or neutron-rich nuclei, high-k isomers physics, theoretical works, technical developments; 2 - Nuclear astrophysics; 3 - Basic symmetries; 4 - Accelerator-based mass spectroscopy; 5 - Solid State Astrophysics; 6 - Physics and Chemistry of Irradiation; 7 - Solid State Physics; 8 - SEMIRAMIS (ion source and ion beam handling); 9 - Computer Department; 10 - Electronics Group; 11 - Mechanics Department; 12 - Permanent training; 13 - Health and safety; 14 - Seminars and communications; 15 - Dissertations; 16 - Publications; 17 - Staff

The mass media and nuclear energy in the U.S

International Nuclear Information System (INIS)

Roche, C.

1994-01-01

The author discusses some problems of mass media of the United States connected with covering issues of nuclear power development, and makes some recommendations to improve the situation in this field

Nuclear deformations, level assignments and static nuclear moments of isotopes in the region 72Hf-77Ir

International Nuclear Information System (INIS)

Ekstroem, C.; Rubinsztein, H.; Moeller, P.

1976-01-01

A comparison is made between experimental and theoretical level assignments and static electromagnetic moments of nuclei in the region 72 Hf- 77 Ir. The theoretical calculations are based on the modified oscillator model. Equilibrium deformation values, epsilon and epsilon 4 , are determined for doubly-even and odd-mass nuclei from the minima in the potential energy surfaces. The influence of the different parameters entering the expressions for the magnetic dipole moment is analysed. The electric quadrupole and hexadecapole moments are calculated on the assumption that the nucleus is a homogeneously charged body with a sharp surface and a shape corresponding to that of an equipotential surface. In some selected cases, the electric multipole moments are evaluated by use of the single-particle wave functions. (Auth.)

Determination of B and Li in nuclear materials by secondary-ion mass spectrometry

International Nuclear Information System (INIS)

Eby, R.E.; Christie, W.H.

1981-01-01

Secondary ion mass spectrometry (SIMS) was used to perform mass and isotopic analysis for B and Li in samples that are not readily amenable to more conventional mass spectrometric techniques (e.g., surface ionization, electron impact, etc.). In this paper three specific applications of SIMS analysis to nuclear materials are discussed: first, the quantitative determination of B and its isotopic composition in borosilicate glasses; second, the determination of the isotopic composition of B and Li in irradiated nuclear-grade aluminum oxide/boron carbide composite pellets, and, lastly, the quantitative and isotopic determination of B and Li in highly radioactive solutions of unknown composition

Nuclear deformation in the configuration-interaction shell model

Science.gov (United States)

Alhassid, Y.; Bertsch, G. F.; Gilbreth, C. N.; Mustonen, M. T.

2018-02-01

We review a method that we recently introduced to calculate the finite-temperature distribution of the axial quadrupole operator in the laboratory frame using the auxiliary-field Monte Carlo technique in the framework of the configuration-interaction shell model. We also discuss recent work to determine the probability distribution of the quadrupole shape tensor as a function of intrinsic deformation β,γ by expanding its logarithm in quadrupole invariants. We demonstrate our method for an isotope chain of samarium nuclei whose ground states describe a crossover from spherical to deformed shapes.

Sphalerons, deformed sphalerons and normal modes

International Nuclear Information System (INIS)

Brihaye, Y.; Kunz, J.; Oldenburg Univ.

1992-01-01

Topological arguments suggest that tha Weinberg-Salam model posses unstable solutions, sphalerons, representing the top of energy barriers between inequivalent vacua of the gauge theory. In the limit of vanishing Weinberg angle, such unstable solutions are known: the sphaleron of Klinkhamer and Manton and at large values of the Higgs mass in addition the deformed sphalerons. Here a systematic study of the discrete normal modes about these sphalerons for the full range Higgs mass is presented. The emergence of deformed sphalerons at critical values of the Higgs mass is seem to be related to the crossing of zero of the eigenvalue of the particular normal modes about the sphaleron. 6 figs., 1 tab., 19 refs. (author)

Gamow-Teller decay and nuclear deformation: implementing of a new total absorption spectrometer, study of isotopes N ≅ Z krypton and strontium

International Nuclear Information System (INIS)

Poirier, E.

2002-12-01

Nuclei with A ∼ 70 along the N=Z line are known to be the scene of phenomena closely related to the nuclear deformation and are of particular interest since theoretical mean field calculations predict that a large part of the Gamow-Teller resonance might be located below the ground state of the mother nucleus and then be accessible through β-decay studies. These results have shown the effect of the shape of the ground state on the intensity of the Gamow-Teller strength. Thus, the experimental determination, through δ-decay, of the Gamow-Teller strength distribution and the comparison to the theoretical predictions allow to pin down the quadrupolar deformation parameter of the ground state of the parent nucleus. In order to study the neutron deficient isotopes of krypton (A=72,73,74,75) and strontium (A=76,77,78) and to establish the β-strength on the full energy range, a new total absorption spectrometer (TAgS) has been built in the frame of an international collaboration and installed at the (SOLDE/CERN mass separator. For the data analysis, the response function R of the spectrometer has been calculated by means of Monte-Carlo simulations, based on the GEANT4 code, and of a statistical description of the level scheme in the daughter nucleus. The β-feeding distribution has been obtained from experimental spectra through a method based on Bayes theorem and then converted into Gamow-Teller strength. The results coming from the 74 Kr decay analysis allow to describe the ground state of such a nucleus as the coexistence of an oblate shape and of a prolate shape. In the case of 76 Sr, the experimental Gamow-Teller strength distribution strongly indicates a prolate deformation. (author)

Effective interactions from q-deformed quark fields

International Nuclear Information System (INIS)

Timoteo, V. S.; Lima, C. L.

2007-01-01

From the mass term for q-deformed quark fields, we obtain effective contact interactions of the NJL type. The parameters of the model that maps a system of non-interacting deformed fields into quarks interacting via NJL contact terms is discussed

Deformation effects in the Si + C and Si + Si reactions

Indian Academy of Sciences (India)

The possible occurrence of highly deformed configurations is investigated in the. ¼ ... Fusion–fission; nuclear deformation; exclusive light charge particle measurements. .... In hot rotating nuclei formed in heavy-ion reactions, the energy level.

Mass estimation of loose parts in nuclear power plant based on multiple regression

International Nuclear Information System (INIS)

He, Yuanfeng; Cao, Yanlong; Yang, Jiangxin; Gan, Chunbiao

2012-01-01

According to the application of the Hilbert–Huang transform to the non-stationary signal and the relation between the mass of loose parts in nuclear power plant and corresponding frequency content, a new method for loose part mass estimation based on the marginal Hilbert–Huang spectrum (MHS) and multiple regression is proposed in this paper. The frequency spectrum of a loose part in a nuclear power plant can be expressed by the MHS. The multiple regression model that is constructed by the MHS feature of the impact signals for mass estimation is used to predict the unknown masses of a loose part. A simulated experiment verified that the method is feasible and the errors of the results are acceptable. (paper)

Sensitivity studies for the main r process: nuclear masses

Directory of Open Access Journals (Sweden)

A. Aprahamian

2014-02-01

Full Text Available The site of the rapid neutron capture process (r process is one of the open challenges in all of physics today. The r process is thought to be responsible for the creation of more than half of all elements beyond iron. The scientific challenges to understanding the origin of the heavy elements beyond iron lie in both the uncertainties associated with astrophysical conditions that are needed to allow an r process to occur and a vast lack of knowledge about the properties of nuclei far from stability. One way is to disentangle the nuclear and astrophysical components of the question. On the nuclear physics side, there is great global competition to access and measure the most exotic nuclei that existing facilities can reach, while simultaneously building new, more powerful accelerators to make even more exotic nuclei. On the astrophysics side, various astrophysical scenarios for the production of the heaviest elements have been proposed but open questions remain. This paper reports on a sensitivity study of the r process to determine the most crucial nuclear masses to measure using an r-process simulation code, several mass models (FRDM, Duflo-Zuker, and HFB-21, and three potential astrophysical scenarios.

Mass shift of σ-meson in nuclear matter

Indian Academy of Sciences (India)

Mass shift of σ-meson in nuclear matter. J R MORONES-IBARRA1, MÓNICA MENCHACA MACIEL1,∗. ,. AYAX SANTOS-GUEVARA2 and FELIPE ROBLEDO PADILLA1. 1Facultad de Ciencias Físico-Matemáticas, Universidad Autónoma de Nuevo León, UANL,. Av. Universidad S/N Ciudad Universitaria, San Nicolás de los ...

Earthquake-induced crustal deformation and consequences for fault displacement hazard analysis of nuclear power plants

International Nuclear Information System (INIS)

Gürpinar, Aybars; Serva, Leonello; Livio, Franz; Rizzo, Paul C.

2017-01-01

Highlights: • A three-step procedure to incorporate coseismic deformation into PFDHA. • Increased scrutiny for faults in the area permanently deformed by future strong earthquakes. • These faults share with the primary structure the same time window for fault capability. • VGM variation may occur due to tectonism that has caused co-seismic deformation. - Abstract: Readily available interferometric data (InSAR) of the coseismic deformation field caused by recent seismic events clearly show that major earthquakes produce crustal deformation over wide areas, possibly resulting in significant stress loading/unloading of the crust. Such stress must be considered in the evaluation of seismic hazards of nuclear power plants (NPP) and, in particular, for the potential of surface slip (i.e., probabilistic fault displacement hazard analysis - PFDHA) on both primary and distributed faults. In this study, based on the assumption that slip on pre-existing structures can represent the elastic response of compliant fault zones to the permanent co-seismic stress changes induced by other major seismogenic structures, we propose a three-step procedure to address fault displacement issues and consider possible influence of surface faulting/deformation on vibratory ground motion (VGM). This approach includes: (a) data on the presence and characteristics of capable faults, (b) data on recognized and/or modeled co-seismic deformation fields and, where possible, (c) static stress transfer between source and receiving faults of unknown capability. The initial step involves the recognition of the major seismogenic structures nearest to the site and their characterization in terms of maximum expected earthquake and the time frame to be considered for determining their “capability” (as defined in the International Atomic Energy Agency - IAEA Specific Safety Guide SSG-9). Then a GIS-based buffer approach is applied to identify all the faults near the NPP, possibly influenced by

Earthquake-induced crustal deformation and consequences for fault displacement hazard analysis of nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Gürpinar, Aybars, E-mail: aybarsgurpinar2007@yahoo.com [Nuclear & Risk Consultancy, Anisgasse 4, 1221 Vienna (Austria); Serva, Leonello, E-mail: lserva@alice.it [Independent Consultant, Via dei Dauni 1, 00185 Rome (Italy); Livio, Franz, E-mail: franz.livio@uninsubria.it [Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell’Insubria, Via Velleggio, 11, 22100 Como (Italy); Rizzo, Paul C., E-mail: paul.rizzo@rizzoasoc.com [RIZZO Associates, 500 Penn Center Blvd., Suite 100, Pittsburgh, PA 15235 (United States)

2017-01-15

Highlights: • A three-step procedure to incorporate coseismic deformation into PFDHA. • Increased scrutiny for faults in the area permanently deformed by future strong earthquakes. • These faults share with the primary structure the same time window for fault capability. • VGM variation may occur due to tectonism that has caused co-seismic deformation. - Abstract: Readily available interferometric data (InSAR) of the coseismic deformation field caused by recent seismic events clearly show that major earthquakes produce crustal deformation over wide areas, possibly resulting in significant stress loading/unloading of the crust. Such stress must be considered in the evaluation of seismic hazards of nuclear power plants (NPP) and, in particular, for the potential of surface slip (i.e., probabilistic fault displacement hazard analysis - PFDHA) on both primary and distributed faults. In this study, based on the assumption that slip on pre-existing structures can represent the elastic response of compliant fault zones to the permanent co-seismic stress changes induced by other major seismogenic structures, we propose a three-step procedure to address fault displacement issues and consider possible influence of surface faulting/deformation on vibratory ground motion (VGM). This approach includes: (a) data on the presence and characteristics of capable faults, (b) data on recognized and/or modeled co-seismic deformation fields and, where possible, (c) static stress transfer between source and receiving faults of unknown capability. The initial step involves the recognition of the major seismogenic structures nearest to the site and their characterization in terms of maximum expected earthquake and the time frame to be considered for determining their “capability” (as defined in the International Atomic Energy Agency - IAEA Specific Safety Guide SSG-9). Then a GIS-based buffer approach is applied to identify all the faults near the NPP, possibly influenced by

New directions at UNISOR and the importance of reinforcing spherical and deformed shell gaps

International Nuclear Information System (INIS)

Hamilton, J.H.

1985-01-01

An on-line nuclear orientation facility under construction for UNISOR is described. The strong competition between shell gaps at spherical, prolate and oblate deformation is shown to give rise to various structures from spherical double closed shell, to coexisting near-spherical and deformed shapes to deformed double closed shell nuclei in the region of A = 70-104. The importance of the reinforcing of the shape driving forces when the nucleus has shell gaps for the protons and neutrons at the same deformation on nuclear shapes and the switching of magic numbers is described

Acoustic emission during tensile deformation and fracture of nuclear grade AISI type 304 stainless steel specimens with notches

International Nuclear Information System (INIS)

Mukhopadhyay, C.K.; Jayakumar, T.; Baldev Raj

1996-01-01

Acoustic emission generated during tensile deformation and fracture of nuclear grade AISI type 304 stainless steel specimens with notches has been studied. The extent of acoustic activity generated depends on notch tip severity, notch tip blunting and tearing of the notches. The equation N=AK m applied to the acoustic emission data of the notched specimens has shown good correlation. Acoustic emission technique can be used to estimate the size of an unknown notch. (author)

Improved predictions of nuclear data: A continued challenge in astrophysics

International Nuclear Information System (INIS)

Goriely, S.

2001-01-01

Although important effort has been devoted in the last decades to measure reaction cross sections and decay half-lives of interest in astrophysics, most of the nuclear astrophysics applications still require the use of theoretical predictions to estimate experimentally unknown rates. The nuclear ingredients to the reaction or weak interaction models should preferentially be estimated from microscopic or semi-microscopic global predictions based on sound and reliable nuclear models which, in turn, can compete with more phenomenological highly-parametrized models in the reproduction of experimental data. The latest developments made in deriving the nuclear inputs of relevance in astrophysics applications are reviewed. It mainly concerns nuclear structure properties (atomic masses, deformations, radii, etc...), nuclear level densities, nucleon and α-optical potentials, γ-ray and Gamow-Teller strength functions

Calculation of the spectrum of {gamma} rays connecting superdeformed and normally deformed nuclear states

Energy Technology Data Exchange (ETDEWEB)

Dossing, T.; Khoo, T.L.; Lauritsen, T. [and others

1995-08-01

The decay out of superdeformed states occurs by coupling to compound nuclear states of normal deformation. The coupling is very weak, resulting in mixing of the SD state with one or two normal compound states. With a high energy available for decay, a statistical spectrum ensues. The shape of this statistical spectrum contains information on the level densities of the excited states below the SD level. The level densities are sensitively affected by the pair correlations. Thus decay-out of a SD state (which presents us with a means to start a statistical cascade from a highly-excited sharp state) provides a method for investigating the reduction of pairing with increasing thermal excitation energy.

Characterization of Nuclear Materials Using Complex of Non-Destructive and Mass-Spectroscopy Methods of Measurements

International Nuclear Information System (INIS)

Gorbunova, A.; Kramchaninov, A.

2015-01-01

Information and Analytical Centre for nuclear materials investigations was established in Russian Federation in the February 2 of 2009 by ROSATOM State Atomic Energy Corporation (the order #80). Its purpose is in preventing unauthorized access to nuclear materials and excluding their illicit traffic. Information and Analytical Centre includes analytical laboratory to provide composition and properties of nuclear materials of unknown origin for their identification. According to Regulation the Centre deals with: · identification of nuclear materials of unknown origin to provide information about their composition and properties; · arbitration analyzes of nuclear materials; · comprehensive research of nuclear and radioactive materials for developing techniques characterization of materials; · interlaboratory measurements; · measurements for control and accounting; · confirmatory measurements. Complex of non-destructive and mass-spectroscopy techniques was developed for the measurements. The complex consists of: · gamma-ray techniques on the base of MGAU, MGA and FRAM codes for uranium and plutonium isotopic composition; · gravimetrical technique with gamma-spectroscopy in addition for uranium content; · calorimetric technique for plutonium mass; · neutron multiplicity technique for plutonium mass; · measurement technique on the base of mass-spectroscopy for uranium isotopic composition; · measurement technique on the base of mass-spectroscopy for metallic impurities. Complex satisfies the state regulation requirements of ensuring the uniformity of measurements including the Russian Federation Federal Law on Ensuring the Uniformity of Measurements #102-FZ, Interstate Standard GOST R ISO/IEC 17025-2006, National Standards of Russian Federation GOST R 8.563-2009, GOST R 8.703-2010, Federal Regulations NRB-99/2009, OSPORB 99/2010. Created complex is provided in reference materials, equipment end certificated techniques. The complex is included in accredited

Atomic mass and characteristic constant of nuclear ground state (CENPL.MCC). Pt. 1

International Nuclear Information System (INIS)

Su Zongdi; Ma Lizhen; Zhou Chunmei; Ge Zhigang

1994-01-01

Atomic mass and characteristic constants for nuclear ground states are basic data for nuclear physics, and necessary ones for basic researches, theoretical calculations, as well as many applied researches. The atomic mass of exotic nuclei quite far from the valley stability are also very important for astrophysics researches. The above-requirement is paid attention to in our setting up this file. The recent and as many as possible data (such as the half-lives of the new nuclides 202 Pt, 208 Hg and 185 Hf and the mass excess of 199 Ir, which were produced and distinguished by Chinese scientists) have been collected, and put into the computer-based data file in brief table format. (1 fig.)

Nuclear reactions of high energy deuterons with medium mass targets

International Nuclear Information System (INIS)

Numajiri, Masaharu; Miura, Taichi; Oki, Yuichi

1994-01-01

Formation cross sections of product nuclides in the nuclear reactions of medium mass targets by 10 GeV deuterons were measured with a gamma-ray spectroscopy. The measured data were compared with the cross sections of 12 GeV protons. (author)

The study of three-dimensional net method of deformation observation

International Nuclear Information System (INIS)

Jia Jinyun

1996-12-01

Due to the influence of all kinds of factors, when buildings and equipment of nuclear power stations, water power stations and so on are in their service, deformations always happen to them. Especially, the breakage, the slide of edge danger rocks and basic displacement in the area of nuclear power station site can all interfere its regular operation, even endanger safety. But the traditional trigonometric net control can not obtain high precise deformation observation. So, topographic balanced vertical deviations are applied. The slope distance is divided rationally into horizontal and vertical components, then the precise vertical component is used to participate in restricting the deflection in order to enhance the observation post's precision. Meanwhile, the element model is selected, high precise monitoring net of three-dimensional deformation is set up, using astro-geodetic deflection of the vertical to correct the observation values. In this way, the earth error of height is given, the plane coordinate is defined by paralleling some plane of reference ellipsoid. This method may satisfy the deformation observation in the projects such as nuclear power stations or so. (8 figs., 5 tabs.)

In situ determination of a rock mass modulus using a high resolution tiltmeter

Energy Technology Data Exchange (ETDEWEB)

Saleh, B.; Husein Malkawi, A.I. [University of Jordan, Amman (Jordan); Blum, P.A. [Universite Pierre et Marie Curie, 75 - Paris (France)

1996-04-01

A very sensitive, compact tiltmeter made of melted silica, developed for the measurement of small deformations of various civil engineering structures, was described. The instrument is capable of giving a continuous record and was used to establish a new approach to directly evaluating the in situ average elastic rock mass modulus. Such information is important in decision making during the design stages of large civil engineering works, such as dams, nuclear plant facilities, and underground structures. Five tiltmeters were installed on the facades of the Louvre in Paris to study the deformation induced by internal structural work and by the impact of the Paris metro traffic movement. The data was used to determine displacement using the Boussinesq equation. Results were consistent with typical elastic rock-mass modulus for the rock found in the museum`s foundations. 13 refs., 1 tab., 10 figs.

M theory on deformed superspace

Science.gov (United States)

Faizal, Mir

2011-11-01

In this paper we will analyze a noncommutative deformation of the Aharony-Bergman-Jafferis-Maldacena (ABJM) theory in N=1 superspace formalism. We will then analyze the Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetries for this deformed ABJM theory, and its linear as well as nonlinear gauges. We will show that the sum of the gauge fixing term and the ghost term for this deformed ABJM theory can be expressed as a combination of the total BRST and the total anti-BRST variation, in Landau and nonlinear gauges. We will show that in Landau and Curci-Ferrari gauges deformed ABJM theory is invariant under an additional set of symmetry transformations. We will also discuss the effect that the addition of a bare mass term has on this theory.

Bifurcations and chaos of classical trajectories in a deformed nuclear potential

International Nuclear Information System (INIS)

Carbonell, J.; Arvieu, R.

1983-01-01

The organization of the phase space of a classical nucleon in an axially symmetric deformed potential with the restriction Lsub(z)=0 is studied by drawing the Poincare surfaces of section. In the limit of small deformations three simple limits help to understand this organization. Moreover important bifurcations of periodic trajectories occur. At higher deformations multifurcations and chaos are observed. Chaos is developed to a larger extent in the heavier nuclei. (author)

Heat and mass transfer and hydrodynamics in two-phase flows in nuclear power plants

International Nuclear Information System (INIS)

Styrikovich, M.A.; Polonskii, V.S.; Tsiklauri, G.V.

1986-01-01

This book examines nuclear power plant equipment from the point of view of heat and mass transfer and the behavior of impurities contained in water and in steam, with reference to real water regimes of nuclear power plants. The transfer processes of equipment are considered. Heat and mass transfer are analyzed in the pre-crisis regions of steam-generating passages with non-permeable surfaces, and in capillary-porous structures. Attention is given to forced convection boiling crises and top post-DNB heat transfer. Data on two-phase hydrodynamics in straight and curved channels are correlated and safety aspects of nuclear power plants are discussed

Some aspects of reflection asymmetric deformations in nuclei

International Nuclear Information System (INIS)

Olanders, P.

1984-10-01

The nuclear shape in the intrinsic frame is studied using the Strutinsky method. Various potentials (Nilsson, folded Yukawa and Woods-Saxon) are used for the microscopic part, and the macroscopic part is described as a liquid drop with either a sharp or a smooth surface. Special attention is paid to the possibility of octupole deformed ground states. The consequences of octupole deformations for the rotational behaviour are investigated using the cranking model. It is particularly shown that octupole deformation may supress the backbending in some nuclei. (author)

The NJL interaction from q-deformed inspired transformations

International Nuclear Information System (INIS)

Timoteo, V.S.; Lima, C.L.

2007-01-01

From the mass term for q-deformed quark fields, we obtain effective contact interactions of the NJL type. The parameters of the model that maps a system of non-interacting deformed fields into quarks interacting via NJL contact terms is discussed. (author)

STAFAN, Fluid Flow, Mechanical Stress in Fractured Rock of Nuclear Waste Repository

International Nuclear Information System (INIS)

Huyakorn, P.; Golis, M.J.

1989-01-01

1 - Description of program or function: STAFAN (Stress And Flow Analysis) is a two-dimensional, finite-element code designed to model fluid flow and the interaction of fluid pressure and mechanical stresses in a fractured rock surrounding a nuclear waste repository. STAFAN considers flow behavior of a deformable fractured system with fracture-porous matrix interactions, the coupling effects of fluid pressure and mechanical stresses in a medium containing discrete joints, and the inelastic response of the individual joints of the rock mass subject to the combined fluid pressure and mechanical loading. 2 - Restrictions on the complexity of the problem: STAFAN does not presently contain thermal coupling, and it is unable to simulate inelastic deformation of the rock mass and variably saturated or two-phase flow in the fractured porous medium system

Combating the terrorist use of mass destruction weapons, particularly nuclear weapons

International Nuclear Information System (INIS)

Barakat, M.

2008-01-01

The risks of mass destruction weapons vary and also forms of damages resulting therefrom. While the effects of nuclear weapons are focused, sudden and comprehensive, the chemical weapons have limited impacts relatively unless used intensively severe prejudice to the element of surprise, and thus impaired the efficacy of their influences,especially that they affect exceptionally the individuals in the area of injury and biological weapons do not announce themselves except through their effect that appears later than the time of use as they affect exceptionally the organisms in the area of injury.The mass destruction weapons have turned from being a purely military means in the early twentieth century and have now become the means of violence against governments and countries that they should prepare themselves for and respond in ways of successful and effective countermeasures. Despite the fact that the acquisition of mass destruction weapons can be considered as a priority objective, which terrorist groups and organizations steadily seek but their accessibility is flanked by a lot of difficulties. Addressing the risk of further spread of nuclear weapons, and especially after doubling the power of those high-risk weapons, the international community has an approach to take a number of arrangements that complement each other to control and resist nuclear proliferation, either for the states or for terrorist groups.

Extrapolations of nuclear binding energies from new linear mass relations

DEFF Research Database (Denmark)

Hove, D.; Jensen, A. S.; Riisager, K.

2013-01-01

We present a method to extrapolate nuclear binding energies from known values for neighboring nuclei. We select four specific mass relations constructed to eliminate smooth variation of the binding energy as function nucleon numbers. The fast odd-even variations are avoided by comparing nuclei...

Intruder level and deformation in SD-pair shell model

International Nuclear Information System (INIS)

Luo Yan'an; Ning Pingzhi; Pan Feng

2004-01-01

The influence of intruder level on nuclear deformation is studied within the framework of the nucleon-pair shell model truncated to an SD-pair subspace. The results suggest that the intruder level has a tendency to reduce the deformation and plays an important role in determining the onset of rotational behavior. (authors)

Nuclear structure studies in the xenon and radon region and the discovery of a new radon isotope by Penning trap mass spectrometry

International Nuclear Information System (INIS)

Neidherr, Dennis

2010-01-01

Nowadays high-precision mass measurements based on Penning traps allow a deep insight into the fundamental properties of nucleonic matter. To this end, the cyclotron frequency ν c =qB=(2πm) of an ion confined in a strong, homogeneous magnetic field B is determined. At the ISOLTRAP mass spectrometer at ISOLDE / CERN the masses of short-lived radioactive nuclei with half-lives down to several ten ms can be measured with an uncertainty in the order of 10 -8 and below. ISOLTRAP consists of an RFQ cooler and buncher to cool and accumulate the ions coming from ISOLDE and a double Penning trap system to first clean the ion samples and finally perform the mass measurements. Within this thesis the masses of neutron rich xenon and radon isotopes, namely 138-146 Xe and 223-229 Rn were determined, eleven of them for the first time. 229 Rn was even discovered in this experiment and its half-life could be determined to 12 -1.3 +1.2 s. Since the mass reflects all interactions inside the nucleus it is a unique fingerprint of the nuclide of interest. One of these interactions, the proton-neutron interaction, leads for example to the onset of deformation. The aim of this thesis is to investigate a possible connection be- tween collective effects in nuclei, like the onset of deformation, and double-differences of binding energies, so called δV pn values. Especially in the here presented areas these δV pn values show a very unusual behavior and can not be explained with simple orbital overlapping arguments. One explanation could be the occurrence of octupolar deformation in these regions, which is usually probed with other experimental techniques. However, a quantitative description of the influence of such type of deformation on δV pn is still not possible with modern theories. (orig.)

Physics-based deformable organisms for medical image analysis

Science.gov (United States)

Hamarneh, Ghassan; McIntosh, Chris

2005-04-01

Previously, "Deformable organisms" were introduced as a novel paradigm for medical image analysis that uses artificial life modelling concepts. Deformable organisms were designed to complement the classical bottom-up deformable models methodologies (geometrical and physical layers), with top-down intelligent deformation control mechanisms (behavioral and cognitive layers). However, a true physical layer was absent and in order to complete medical image segmentation tasks, deformable organisms relied on pure geometry-based shape deformations guided by sensory data, prior structural knowledge, and expert-generated schedules of behaviors. In this paper we introduce the use of physics-based shape deformations within the deformable organisms framework yielding additional robustness by allowing intuitive real-time user guidance and interaction when necessary. We present the results of applying our physics-based deformable organisms, with an underlying dynamic spring-mass mesh model, to segmenting and labelling the corpus callosum in 2D midsagittal magnetic resonance images.

Proposal for the determination of nuclear masses by high-precision spectroscopy of Rydberg states

International Nuclear Information System (INIS)

Wundt, B J; Jentschura, U D

2010-01-01

The theoretical treatment of Rydberg states in one-electron ions is facilitated by the virtual absence of the nuclear-size correction, and fundamental constants like the Rydberg constant may be in the reach of planned high-precision spectroscopic experiments. The dominant nuclear effect that shifts transition energies among Rydberg states therefore is due to the nuclear mass. As a consequence, spectroscopic measurements of Rydberg transitions can be used in order to precisely deduce nuclear masses. A possible application of this approach to hydrogen and deuterium, and hydrogen-like lithium and carbon is explored in detail. In order to complete the analysis, numerical and analytic calculations of the quantum electrodynamic self-energy remainder function for states with principal quantum number n = 5, ..., 8 and with angular momentum l = n - 1 and l = n - 2 are described (j = l +- 1/2).

Proposal for the determination of nuclear masses by high-precision spectroscopy of Rydberg states

Energy Technology Data Exchange (ETDEWEB)

Wundt, B J; Jentschura, U D [Department of Physics, Missouri University of Science and Technology, Rolla, MO 65409-0640 (United States)

2010-06-14

The theoretical treatment of Rydberg states in one-electron ions is facilitated by the virtual absence of the nuclear-size correction, and fundamental constants like the Rydberg constant may be in the reach of planned high-precision spectroscopic experiments. The dominant nuclear effect that shifts transition energies among Rydberg states therefore is due to the nuclear mass. As a consequence, spectroscopic measurements of Rydberg transitions can be used in order to precisely deduce nuclear masses. A possible application of this approach to hydrogen and deuterium, and hydrogen-like lithium and carbon is explored in detail. In order to complete the analysis, numerical and analytic calculations of the quantum electrodynamic self-energy remainder function for states with principal quantum number n = 5, ..., 8 and with angular momentum l = n - 1 and l = n - 2 are described (j = l {+-} 1/2).

Table of superdeformed nuclear bands and fission isomers

International Nuclear Information System (INIS)

Firestone, R.B.; Singh, B.

1994-06-01

A minimum in the second potential well of deformed nuclei was predicted and the associated shell gaps are illustrated in the harmonic oscillator potential shell energy surface calculations shown in this report. A strong superdeformed minimum in 152 Dy was predicted for β 2 -0.65. Subsequently, a discrete set of γ-ray transitions in 152 DY was observed and, assigned to the predicted superdeformed band. Extensive research at several laboratories has since focused on searching for other mass regions of large deformation. A new generation of γ-ray detector arrays is already producing a wealth of information about the mechanisms for feeding and deexciting superdeformed bands. These bands have been found in three distinct regions near A=l30, 150, and 190. This research extends upon previous work in the actinide region near A=240 where fission isomers were identified and also associated with the second potential well. Quadrupole moment measurements for selected cases in each mass region are consistent with assigning the bands to excitations in the second local minimum. As part of our committment to maintain nuclear structure data as current as possible in the Evaluated Nuclear Structure Reference File (ENSDF) and the Table of Isotopes, we have updated the information on superdeformed nuclear bands. As of April 1994, we have complied data from 86 superdeformed bands and 46 fission isomers identified in 73 nuclides for this report. For each nuclide there is a complete level table listing both normal and superdeformed band assignments; level energy, spin, parity, half-life, magneto moments, decay branchings; and the energies, final levels, relative intensities, multipolarities, and mixing ratios for transitions deexciting each level. Mass excess, decay energies, and proton and neutron separation energies are also provided from the evaluation of Audi and Wapstra

Table of superdeformed nuclear bands and fission isomers

Energy Technology Data Exchange (ETDEWEB)

Firestone, R.B. [Lawrence Berkeley Lab., CA (United States); Singh, B. [McMaster Univ., Hamilton, ON (Canada)

1994-06-01

A minimum in the second potential well of deformed nuclei was predicted and the associated shell gaps are illustrated in the harmonic oscillator potential shell energy surface calculations shown in this report. A strong superdeformed minimum in {sup 152}Dy was predicted for {beta}{sub 2}-0.65. Subsequently, a discrete set of {gamma}-ray transitions in {sup 152}DY was observed and, assigned to the predicted superdeformed band. Extensive research at several laboratories has since focused on searching for other mass regions of large deformation. A new generation of {gamma}-ray detector arrays is already producing a wealth of information about the mechanisms for feeding and deexciting superdeformed bands. These bands have been found in three distinct regions near A=l30, 150, and 190. This research extends upon previous work in the actinide region near A=240 where fission isomers were identified and also associated with the second potential well. Quadrupole moment measurements for selected cases in each mass region are consistent with assigning the bands to excitations in the second local minimum. As part of our committment to maintain nuclear structure data as current as possible in the Evaluated Nuclear Structure Reference File (ENSDF) and the Table of Isotopes, we have updated the information on superdeformed nuclear bands. As of April 1994, we have complied data from 86 superdeformed bands and 46 fission isomers identified in 73 nuclides for this report. For each nuclide there is a complete level table listing both normal and superdeformed band assignments; level energy, spin, parity, half-life, magneto moments, decay branchings; and the energies, final levels, relative intensities, multipolarities, and mixing ratios for transitions deexciting each level. Mass excess, decay energies, and proton and neutron separation energies are also provided from the evaluation of Audi and Wapstra.

Exact holography of the mass-deformed M2-brane theory

Energy Technology Data Exchange (ETDEWEB)

Jang, Dongmin; Kim, Yoonbai; Kwon, O. Kab [Sungkyunkwan University, Department of Physics, BK21 Physics Research Division, Institute of Basic Science, Suwon (Korea, Republic of); Tolla, D.D. [Sungkyunkwan University, Department of Physics, BK21 Physics Research Division, Institute of Basic Science, Suwon (Korea, Republic of); Sungkyunkwan University, University College, Suwon (Korea, Republic of)

2017-05-15

We test the holographic relation between the vacuum expectation values of gauge invariant operators in N = 6 U{sub k}(N) x U{sub -k}(N) mass-deformed ABJM theory and the LLM geometries with Z{sub k} orbifold in 11-dimensional supergravity. To do so, we apply the Kaluza-Klein reduction to construct a 4-dimensional gravity theory and implement the holographic renormalization procedure. We obtain an exact holographic relation for the vacuum expectation values of the chiral primary operator with conformal dimension Δ = 1, which is given by left angle O{sup (Δ=1)} right angle = N{sup (3)/(2)} f{sub (Δ=1)}, for large N and k = 1. Here the factor f{sub (Δ)} is independent of N. Our results involve an infinite number of exact dual relations for all possible supersymmetric Higgs vacua and so provide a non-trivial test of gauge/gravity duality away from the conformal fixed point. We extend our results to the case of k ≠ 1 for LLM geometries represented by rectangular-shaped Young diagrams. We also discuss the exact mapping of the gauge/gravity at finite N for classical supersymmetric vacuum solutions in field theory side and corresponding classical solutions in gravity side. (orig.)

Accelerator Mass Spectrometry with 15 UD pelletron at the Nuclear Science Centre, New Delhi

International Nuclear Information System (INIS)

Datta, S.K.

1997-01-01

The 15 UD Pelletron machine is widely used to carry on investigations in a variety of disciplines like nuclear physics, materials science, radiobiology etc. Accelerator Mass Spectrometry studies with 15 UD pelletron machine at Nuclear Science Centre are elaborated

Alterations in the nuclear matrix protein mass correlate with heat-induced inhibition of DNA single-strand-break repair

International Nuclear Information System (INIS)

Warters, R.L.; Brizgys, L.M.; Lyons, B.W.

1987-01-01

The total protein mass co-isolating with the nuclear matrix or nucleoid from Chinese hamster ovary (CHO) cells was observed to increase in heated cells as a function of increasing exposure temperature between 43 0 C and 45 0 C or of exposure time at any temperature. The sedimentation distance of the CHO cell nucleoid in sucrose gradients increased with increasing exposure time at 45 0 C. Both these nuclear alterations correlated in a log-linear manner with heat-induced inhibition of DNA strand break repair. A two-fold threshold increase in nuclear matrix protein mass preceded any substantial inhibition of repair of DNA single-strand breaks. When preheated cells were incubated at 37 0 C the nuclear matrix protein mass and nucleoid sedimentation recovered with a half-time of about 5 h, while DNA single-strand-break repair recovered with a half-time of about 2 h. When preheated cells were placed at 41 0 C a further increase was observed in the nuclear matrix protein mass and the half-time of DNA strand break repair, while nucleoid sedimentation recovered toward control values. These results implicate alterations in the protein mass of the nuclear matrix in heat-induced inhibition of repair of DNA single-strand breaks. (author)

Isotopic abundance measurements on solid nuclear-type samples by glow discharge mass spectrometry

International Nuclear Information System (INIS)

Betti, M.; Rasmussen, G.; Koch, L.

1996-01-01

A double-focusing glow discharge mass spectrometer (GDMS) installed in a glovebox for nuclear sample screening has been employed for isotopic measurements. Isotopic compositions of zirconium, silicon, lithium, boron, uranium and plutonium which are elements of nuclear concern have been determined. Interferences arising from the matrix sample and the discharge gas (Ar) for each of these elements are discussed. The GDMS results are compared with those from thermal ionization mass spectrometry (TIMS). For boron and lithium at μg/g-ng/g levels, the two methods gave results in good agreement. In samples containing uranium the isotopic composition obtained by GDMS was in agreement with those from TIMS independently of the enrichment. Attempts for the determination of plutonium isotopic composition were also made. In this case, due to the interferences of uranium at mass 238 and americium at mass 241, the GDMS raw data are complementary with those values obtained from physical non-destructive techniques. (orig.). With 2 figs., 4 tabs

Ablation and deceleration of mass-driver launched projectiles for space disposal of nuclear wastes

International Nuclear Information System (INIS)

Park, C.; Bowen, S.W.

1981-01-01

The energy cost of launching a projectile containing nuclear waste is two orders of magnitude lower with a mass driver than with a typical rocket system. A mass driver scheme will be feasible, however, only if ablation and deceleration are within certain tolerable limits. It is shown that if a hemisphere-cylinder-shaped projectile protected thermally with a graphite nose is launched vertically to attain a velocity of 17 km/sec at an altitude of 40 km, the mass loss from ablation during atmospheric flight will be less than 0.1 ton, provided the radius of the projectile is under 20 cm and the projectile's mass is of the order of 1 ton. The velocity loss from drag will vary from 0.4 to 30 km/sec, depending on the mass and radius of the projectile, the smaller velocity loss corresponding to large mass and small radius. Ablation is always within a tolerable range for schemes using a mass driver launcher to dispose of nuclear wastes outside the solar system. Deceleration can also be held in the tolerable range if the mass and diameter of the projectile are properly chosen

Characterisation of nuclear fuel samples by quadrupole and multi-collector inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Wernli, Beath; Guenther-Leopold, Ines; Kobler Waldis, Judith; Kopajtic, Zlatan

2003-01-01

The characterisation of nuclear fuel cycle materials for trace and minor metallic constituents is of great interest for the nuclear industry and safeguard officials. The main objective of various international programmes dealing with postirradiation examinations is to improve the knowledge of the inventories of actinides, fission and spallation products in spent nuclear fuels. The low detection limits for a large number of elements combined with the ability to analyse the isotopic composition of the elements have established inductively coupled plasma mass spectrometry (ICP-MS) as a powerful multi-element technique in diverse analytical applications for the characterisation of nuclear materials. Because numerous isobaric overlaps restrict the direct determination of many fission products by mass spectrometry, extensive chemical separations are required for these elements. In order to simplify this sample preparation procedure, a high performance liquid chromatography system (HPLC) was online coupled to the mass spectrometer. Since about 10 years a quadrupole based ICP-MS (Q-ICP-MS) combined with an HPLC is used within the Hot Laboratory of the Paul Scherrer Institut for different applications on nuclear fuel samples. Since May 2003 also a new multi-collector ICP-MS (MC-ICP-MS) is used for the mass spectrometric characterisation of nuclear fuel samples, especially for the precise determination of the isotopic vectors of fission products and actinides. Therefore, two complementary analytical systems are now available in the group of 'Isotope and Wet Analytical Chemistry'. A comparison of the analytical performance of both systems (with and without an online coupled HPLC system) for the determination of the isotopic composition and the elemental concentration of different nuclides in nuclear fuel samples, the advantages and limitations of both techniques, the accuracy and precision of the results and typical applications for both methods will be discussed in the

Disappearance of neutron magic numbers and deformation coexistence

International Nuclear Information System (INIS)

Kimura, Masaaki

2014-01-01

The disappearance of N=8, 20 and 28 magic numbers in the neutron excess nuclei is a representative example of the special features of the unstable nuclei. In this lecture of summer school, the problems of the magic number disappearance are presented. And the appearance of the deformation coexistence and the anomalous cluster structure come into the problem with them. At the begging the Antisymmetrized Molecular Dynamic (AMD) framework is explained with finite range two body central force and Gorgny DIS force composed of the zero range spin-orbit force and saturability. Island of inversion is explained in the nuclear chart shown in the figure and energy curves of the nuclei near 32 Mg and the excitation level schemes of 32 Mg are shown in the serial figures. As one of the extreme example of the nuclear structure the deformation of 19 F is picked up. The level schemes and structures of 21 F are shown as well. The molecule-like structure in the island of inversion is clear. The rotational band energy of fluorine isotopes are shown up to 29 F. As a new deformation area, disappearance of N=28 magic number is in the spotlight recently. In this case it is characteristic properties that the parities of the orbits to form the gap must be the same but the angular momenta should be different by 2. According to the AMD research, it is shown that deformations of prolate, three-axis asymmetric and oblate characters coexist in the very low excitation energy region accompanying the disappearance of N=28 gap. The concept of magic numbers has been very fundamental in nuclear physics since the success of shell model. At present its disappearance in the unstable nuclei is one of the most challenging problems in the understanding of the nuclear many body problems. (S. Funahashi)

A study of beta decay energies and atomic masses

International Nuclear Information System (INIS)

Spanier, L.

1988-04-01

The q β energies of 123-131 In have been determined using the end points of β spectra recorded in β-γ coincidence experiments. A HPGe planar detector was used to detect the β-particles and a semi-empirical response function was used when unfolding the electron distribution. The mass excesses were deduced and when they were compared with the predictions of various mass formulae, the cadmium isotopes were found to be heavier than those predicted by most of the mass formulae. The excitation energy of the 1/2 - proton-hole state in the odd indium isotopes was shown to be constant for all the heavy isotopes. The Q EC energies of 148 Dy and 96 Pd were determined using the β + /EC intensity ratio method. The ratio of the intensity of the β+ branch to the total beta decay intensity was determined by means of γ-spectroscopic methods. The mass excesses were deduced. The two-proton binding energy for the N=82 isotones showed only a small step of approximately 0.5 MeV when the doubly-magic nucleus 146 Gd was encountered. A liquid drop type mass formula with deformation and shell energy corrections and with few free parameters is presented. The shell energy correction is a simple analytical expression for the equilibrium deformation of the nucleus. An analytical expression for the equilibrium nuclear deformation is also presented. The mass formula was applied to nuclei with Z and N greater than 50. The RMS deviation is 0.55 milli mass units. The reaction 98 Mo(p,n) 98 Tc was investigated through the counter ratio method, the ratio of the number of slow neutrons to the number of fast neutrons. The Q pn energy value of a low-spin state in 98 Tc was determined. The state at 90.9 keV excitation energy is proposed to be the 14.6 m u s isomer and have spin and parity 1 + . (author)

Integrating viscoelastic mass spring dampers into position-based dynamics to simulate soft tissue deformation in real time.

Science.gov (United States)

Xu, Lang; Lu, Yuhua; Liu, Qian

2018-02-01

We propose a novel method to simulate soft tissue deformation for virtual surgery applications. The method considers the mechanical properties of soft tissue, such as its viscoelasticity, nonlinearity and incompressibility; its speed, stability and accuracy also meet the requirements for a surgery simulator. Modifying the traditional equation for mass spring dampers (MSD) introduces nonlinearity and viscoelasticity into the calculation of elastic force. Then, the elastic force is used in the constraint projection step for naturally reducing constraint potential. The node position is enforced by the combined spring force and constraint conservative force through Newton's second law. We conduct a comparison study of conventional MSD and position-based dynamics for our new integrating method. Our approach enables stable, fast and large step simulation by freely controlling visual effects based on nonlinearity, viscoelasticity and incompressibility. We implement a laparoscopic cholecystectomy simulator to demonstrate the practicality of our method, in which liver and gallbladder deformation can be simulated in real time. Our method is an appropriate choice for the development of real-time virtual surgery applications.

A finite element simulation on transient large deformation and mass diffusion in electrodes for lithium ion batteries

International Nuclear Information System (INIS)

An, Yonghao; Jiang, Hanqing

2013-01-01

Lithium-ion batteries have attracted great deal of attention recently. Silicon is one of the most promising anode materials for high-performance lithium-ion batteries, due to its highest theoretical specific capacity. However, the short lifetime confined by mechanical failure in the silicon anode is now considered to be the biggest challenge in desired applications. High stress induced by the huge volume change due to lithium insertion/extraction is the main reason underlying this problem. Some theoretical models have been developed to address this issue. In order to properly implement these models, we develop a finite element based numerical method using a commercial software package, ABAQUS, as a platform at the continuum level to study fully coupled large deformation and mass diffusion problem. Using this method, large deformation, elasticity–plasticity of the electrodes, various spatial and temporal conditions, arbitrary geometry and dimension could be fulfilled. The interaction between anode and other components of the lithium ion batteries can also be studied as an integrated system. Several specific examples are presented to demonstrate the capability of this numerical platform. (paper)

The nuclear deformation versus the spin-flip like excitations and the suppression of the 2 νββ decay amplitude

International Nuclear Information System (INIS)

Raduta, A. A.; Delion, D. S.; Faessler, A.

1998-01-01

The suppression mechanism of the Gamow-Teller double beta decay amplitude M GT is studied using a many body Hamiltonian which describes a composite system of protons and neutrons moving in a projected spherical single particle basis. Alike nucleons interact through pairing, while protons and neutrons by a separable dipole-dipole force both in the particle-hole (ph) and particle-particle (pp) channels. The spin-flip and non-spin-flip components of the QRPA phonons have different contributions to the M GT value. The relative magnitudes and phases depend on both the strength of the particle-particle interaction (g pp ) and nuclear deformation. The deformation yields a fragmentation of the M GT value on one hand and washes out the separation of states of pure spin-flip and non spin-flip structures. Due to this effect, M GT has only one fragmented resonance structure in the low part of the spectrum. The mechanism of M GT suppression is different for spherical and deformed nuclei. While for spherical situation the resonances of pure spin-flip and non spin-flip character are separated in energy, for deformed case the two resonances coincide. In both cases, approaching the critical value of g pp , where the Random Phase Approximation (RPA) breaks down, a lot of strength is accumulated in the lowest RPA state. The difference is that, while in the spherical case this has a non spin-flip nature, in the deformed case the state is a mixture of both types of configurations. (authors)

: Nuclear Spirals and Mass Accretion to Supermassive Black Holes in Weakly-Barred Galaxies

Science.gov (United States)

Kim, Woong-Tae; Elmegreen, Bruce

2018-01-01

Disk galaxies, especially barred-spiral galaxies, abound with rings and spirals in their nuclear regions. Nuclear spirals existing even in weakly barred galaxies are thought to channel gas inflows to supermassive black holes residing at the centers. We use high-resolution hydrodynamic simulations to study the properties of nuclear gas spirals driven by weak bar-like or oval potentials. The amplitude of the spirals increases toward the center by a geometric effect, readily developing into shocks at small radii even for very weak potentials. The shape of the spirals and shocks depends rather sensitively on the background shear. When shear is low, the nuclear spirals are loosely wound and the shocks are almost straight, resulting in large mass inflows toward the center. When shear is high, on the other hand, the spirals are tightly wound and the shocks are oblique, forming a circumnuclear disk through which gas flows inward at a relatively lower rate. The induced mass inflow rates are enough to power black hole accretion in various types of Seyfert galaxies.

A quadrupole mass spectrometer system for nuclear safeguards applications

International Nuclear Information System (INIS)

Evans, P.J.

1987-12-01

An on-line enrichment monitor for nuclear safeguards-related surveillance of a pilot-scale gas centrifuge plant is described. This monitor utilises a quadrupole mass spectrometer to measure the isotopic composition of UF 6 in the feed and product gas streams. Details of the design and construction are given, and several difficulties are identified and discussed. Finally, the performance of this system is illustrated with typical results

The impact of global nuclear mass model uncertainties on r-process abundance predictions

Directory of Open Access Journals (Sweden)

Mumpower M.

2015-01-01

Full Text Available Rapid neutron capture or ‘r-process’ nucleosynthesis may be responsible for half the production of heavy elements above iron on the periodic table. Masses are one of the most important nuclear physics ingredients that go into calculations of r-process nucleosynthesis as they enter into the calculations of reaction rates, decay rates, branching ratios and Q-values. We explore the impact of uncertainties in three nuclear mass models on r-process abundances by performing global monte carlo simulations. We show that root-mean-square (rms errors of current mass models are large so that current r-process predictions are insufficient in predicting features found in solar residuals and in r-process enhanced metal poor stars. We conclude that the reduction of global rms errors below 100 keV will allow for more robust r-process predictions.

Formation of fission-fragment mass distribution for nuclei lighter than thorium

International Nuclear Information System (INIS)

Itkis, M.G.; Mul'gin, S.I.; Rusanov, A.Y.; Okolovich, A.N.; Smirenkin, G.N.

1986-01-01

A phenomenological approach to description of fission-fragment mass distribution Y(M) for nuclei in the vicinity of Pb is developed and used to extract from the experimental Y(M) data the nuclear deformation potential energy V(M) and its components: the macroscopic (liquid-drop) part and the shell correction in the transition state. The results of the analysis are compared with the theoretically obtained V(M) and Y(M). The three-hump fragment-mass distributions observed in Ra fission are satisfactorily described within the framework of the approach developed. The properties of the symmetric and asymmetric fission valleys and the related Y(M) components are discussed

Hyperfine structure, nuclear spins and magnetic moments of some cesium isotopes

International Nuclear Information System (INIS)

Ekstroem, C.; Ingelman, S.; Wannberg, G.

1977-03-01

Using an atomic-beam magnetic resonance apparatus connected on-line with the ISOLDE isotope separator, CERN, hyperfine structure measurements have been performed in the 2 Ssub(1/2) electronic ground state of some cesium isotopes. An on-line oven system which efficiently converts a mass separated ion-beam of alkali isotopes to an atomic beam is described in some detail. Experimentally determined nuclear spins of sup(120, 121, 121m, 122, 122m, 123, 124, 126, 128, 130m, 135m)Cs and magnetic moments of sup(122, 123, 124, 126, 128, 130)Cs are reported and discussed in terms of different nuclear models. The experimental data indicate deformed nuclear shapes of the lightest cesium isotopes. (Auth.)

The management-retrieval code of the sub-library of atomic mass and characteristic constants for nuclear ground state

International Nuclear Information System (INIS)

Su Zongdi; Ma Lizhen

1994-01-01

The management code of the sub-library of atomic mass and characteristic constants for nuclear ground state (MCC) is used for displaying the basic information on the MCC sub-library on the screen, and retrieving the required data. The MCC data file contains the data of 4800 nuclides ranging from Z 0, A = 1 to Z = 122, A = 318. The MCC sub-library has been set up at Chinese Nuclear Data Center (CNDC), and has been used to provide the atomic masses and characteristic constants of nuclear ground states for the nuclear model calculation, nuclear data evaluations and other fields

The kinetic energy operator for distance-dependent effective nuclear masses: Derivation for a triatomic molecule.

Science.gov (United States)

Khoma, Mykhaylo; Jaquet, Ralph

2017-09-21

The kinetic energy operator for triatomic molecules with coordinate or distance-dependent nuclear masses has been derived. By combination of the chain rule method and the analysis of infinitesimal variations of molecular coordinates, a simple and general technique for the construction of the kinetic energy operator has been proposed. The asymptotic properties of the Hamiltonian have been investigated with respect to the ratio of the electron and proton mass. We have demonstrated that an ad hoc introduction of distance (and direction) dependent nuclear masses in Cartesian coordinates preserves the total rotational invariance of the problem. With the help of Wigner rotation functions, an effective Hamiltonian for nuclear motion can be derived. In the derivation, we have focused on the effective trinuclear Hamiltonian. All necessary matrix elements are given in closed analytical form. Preliminary results for the influence of non-adiabaticity on vibrational band origins are presented for H 3 + .

Passive sorting of capsules by deformability

Science.gov (United States)

Haener, Edgar; Juel, Anne

We study passive sorting according to deformability of liquid-filled ovalbumin-alginate capsules. We present results for two sorting geometries: a straight channel with a half-cylindrical obstruction and a pinched flow fractioning device (PFF) adapted for use with capsules. In the half-cylinder device, the capsules deform as they encounter the obstruction, and travel around the half-cylinder. The distance from the capsule's centre of mass to the surface of the half-cylinder depends on deformability, and separation between capsules of different deformability is amplified by diverging streamlines in the channel expansion downstream of the obstruction. We show experimentally that capsules can be sorted according to deformability with their downstream position depending on capillary number only, and we establish the sensitivity of the device to experimental variability. In the PFF device, particles are compressed against a wall using a strong pinching flow. We show that capsule deformation increases with the intensity of the pinching flow, but that the downstream capsule position is not set by deformation in the device. However, when using the PFF device like a T-Junction, we achieve improved sorting resolution compared to the half-cylinder device.

Nuclear technology: katulong sa pag-unlad ng masa [support for the progress of the masses

International Nuclear Information System (INIS)

1999-01-01

The topics discussed during the convention is the usefulness of nuclear science and technology in national development and to promote the beneficial uses of nuclear science and technology to support for the progress of the masses

Software in windows for staple compounding system of microcomputer nuclear mass scale

International Nuclear Information System (INIS)

Wang Yanting; Zhang Yongming; Wang Yu; Jin Dongping

1998-01-01

The software exploited in windows for staple compounding system of microcomputer nuclear mass scale is described. The staple compounding system is briefly narrated. The software structure and its realizing method are given

Neutron scattering on deformed nuclei

International Nuclear Information System (INIS)

Hansen, L.F.; Haight, R.C.; Pohl, B.A.; Wong, C.; Lagrange, C.

1984-09-01

Measurements of neutron elastic and inelastic differential cross sections around 14 MeV for 9 Be, C, 181 Ta, 232 Th, 238 U and 239 Pu have been analyzed using a coupled channel (CC) formalism for deformed nuclei and phenomenological global optical model potentials (OMP). For the actinide targets these results are compared with the predictions of a semi-microscopic calculation using Jeukenne, Lejeune and Mahaux (JLM) microscopic OMP and a deformed ground state nuclear density. The overall agreement between calculations and the measurements is reasonable good even for the very light nuclei, where the quality of the fits is better than those obtained with spherical OMP

Double-arm time-of-flight mass-spectrometer of nuclear fragments

International Nuclear Information System (INIS)

Ajvazian, G.M.; Astabatyan, R.A.

1995-01-01

A double-arm time-of-flight spectrometer of nuclear fragments for the investigation of heavy nuclei photofission in the intermediate energy range is described. The calibration results and working characteristics of the spectrometer, obtained using 252 Cf as a source of spontaneous fission, are presented. A mass resolution of σ m ∼2-3 a.m.u. was obtained within the registered fragments mass range of 80-160 a.m.u. The spectrometer was tested in the experiment on the investigation of 238 U nuclei fission by Bremsstahlung photons with Eγ max=1.75 GeV

The Impact of the Rock Mass Deformation on Geometric Changes of a Historical Chimney in the Salt Mine of Bochnia

Science.gov (United States)

Szafarczyk, Anna; Gawałkiewicz, Rafał

2018-03-01

There are many ways of the geometry measurement of slim objects, with the application of geodetic and photogrammetric methods. A modern solution in the diagnostics of slim objects is the application of laser scanning, with the use of a scanner of a scanning total station. The point cloud, obtained from the surface of the scanned object gives the possibility of generating not only information on structural surface deformations, but also facilitates obtaining the data on the geometry of the axis of the building, as a basic indicator of the characteristics of its deformation. The cause of the change in the geometry of slim objects is the impact of many external and internal factors. These objects are located in the areas of working or closed underground mines. They can be impacted by the ground and they can face the results of the convergence of cavities. A specific structure of the salt rock mass causes subsequent convergence of the post-exploitation cavities, which has the influence on the behaviour of the terrain surface and the related objects. The authors analysed the impact of the changes in the rock mass and the surface on the changes of the industrial chimney in the Bochnia Salt Mine.

Nuclear structure studies in the xenon and radon region and the discovery of a new radon isotope by Penning trap mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Neidherr, Dennis

2010-04-28

Nowadays high-precision mass measurements based on Penning traps allow a deep insight into the fundamental properties of nucleonic matter. To this end, the cyclotron frequency {nu}{sub c}=qB=(2{pi}m) of an ion confined in a strong, homogeneous magnetic field B is determined. At the ISOLTRAP mass spectrometer at ISOLDE / CERN the masses of short-lived radioactive nuclei with half-lives down to several ten ms can be measured with an uncertainty in the order of 10{sup -8} and below. ISOLTRAP consists of an RFQ cooler and buncher to cool and accumulate the ions coming from ISOLDE and a double Penning trap system to first clean the ion samples and finally perform the mass measurements. Within this thesis the masses of neutron rich xenon and radon isotopes, namely {sup 138-146}Xe and {sup 223-229}Rn were determined, eleven of them for the first time. {sup 229}Rn was even discovered in this experiment and its half-life could be determined to 12{sub -1.3}{sup +1.2} s. Since the mass reflects all interactions inside the nucleus it is a unique fingerprint of the nuclide of interest. One of these interactions, the proton-neutron interaction, leads for example to the onset of deformation. The aim of this thesis is to investigate a possible connection be- tween collective effects in nuclei, like the onset of deformation, and double-differences of binding energies, so called {delta}V{sub pn} values. Especially in the here presented areas these {delta}V{sub pn} values show a very unusual behavior and can not be explained with simple orbital overlapping arguments. One explanation could be the occurrence of octupolar deformation in these regions, which is usually probed with other experimental techniques. However, a quantitative description of the influence of such type of deformation on {delta}V{sub pn} is still not possible with modern theories. (orig.)

Uniformity measure for power-law mass spectrum in nuclear fragmentation

International Nuclear Information System (INIS)

Wislicki, W.

1992-11-01

Description is given in terms of the Renyi entropy and the uniformity for the canonical ensemble, the grand canonical ensemble and the power-law probability measures. The study is presented of the power-law spectra of cluster masses observed in nuclear interactions in the vicinity of the liquid-gas transition point. 6 figs., 1 tab., 15 refs. (author)

Intermediate energy nuclear fission

International Nuclear Information System (INIS)

Hylten, G.

1982-01-01

Nuclear fission has been investigated with the double-kinetic-energy method using silicon surface barrier detectors. Fragment energy correlation measurements have been made for U, Th and Bi with bremsstrahlung of 600 MeV maximum energy. Distributions of kinetic energy as a function of fragment mass are presented. The results are compared with earlier photofission data and in the case of bismuth, with calculations based on the liquid drop model. The binary fission process in U, Yb, Tb, Ce, La, Sb, Ag and Y induced by 600 MeV protons has been investigated yielding fission cross sections, fragment kinetic energies, angular correlations and mass distributions. Fission-spallation competition calculations are used to deduce values of macroscopic fission barrier heights and nuclear level density parameter values at deformations corresponding to the saddle point shapes. We find macroscopic fission barriers lower than those predicted by macroscopic theories. No indication is found of the Businaro Gallone limit expected to occur somewhere in the mass range A = 100 to A = 140. For Ce and La asymmetric mass distributions similar to those in the actinide region are found. A method is described for the analysis of angular correlations between complementary fission products. The description is mainly concerned with fission induced by medium-energy protons but is applicable also to other projectiles and energies. It is shown that the momentum and excitation energy distributions of cascade residuals leading to fission can be extracted. (Author)

On the study of level density parameters for some deformed light nuclei

International Nuclear Information System (INIS)

Sonmezoglu, S.

2005-01-01

The nuclear level density, which is the number of energy levels/MeV at an excitation energy Ex , is a characteristic property of every nucleus. Total level densities are among the key quantities in statistical calculations in many fields, such as nuclear physics, astrophysics, spallation s neutrons measurements, and studies of intermediate-energy heavy-ion collisions. The nuclear level density is an important physical quantity both from the fundamental point of view as well as in understanding the particle and gamma ray emission in various reactions. In light and heavy deformed nucleus, the gamma-ray energies drop with decreasing spin in a very regular fashion. The nuclear level density parameters have been usually used in investigation of the nuclear level density. This parameter itself changes with excitation energy depending on both shell effect in the single particle model and different excitation modes in the collective models. In this study, the energy level density parameters of some deformed light nucleus (40 C a, 47 T i, 59 N i, 79 S e, 80 B r) are determined by using energy spectrum of the interest nucleus for different band. In calculation of energy-level density parameters dependent upon excitation energy of nuclei studied, a model was considered which relies on the fact that energy levels of deformed light nuclei, just like those of deformed heavy nuclei, are equidistant and which relies on collective motions of their nucleons. The present calculation results have been compared with the corresponding experimental and theoretical results. The obtained results are in good agreement with the experimental results

Nuclear assay of coal. Volume 6. Mass flow devices for coal handling

International Nuclear Information System (INIS)

Anon.

1979-01-01

The mass of coal entering the boiler per unit time is an essential parameter for determinig the total rate of heat input. The mass flow rate of coal on a conveyor belt is generally determined as a product of the instantaneous mass of material on a short section of the belt and the belt velocity. Belt loading could be measured by conventional transducers incorporating mechanical or electromechanical weighers or by gamma-ray attenuation gauge. This report reviews the state of the art in mass flow devices for coal handling. The various methods are compared and commented upon. Special design issues are discussed relative to incorporating a mass flow measuring device in a Continuous On-Line Nuclear Analysis of Coal (CONAC) system

Nuclear chemistry

International Nuclear Information System (INIS)

Anon.

1979-01-01

Topics covered include: mass asymmetry and total kinetic energy release in the spontaneous fission of 262 105; calculation of spontaneous fission properties of very heavy nuclei - 98 less than or equal to Z less than or equal to 106 and 150 less than or equal to N less than or equal to 164; energy losses for 84 Kr ions in nickel, aluminium and titanium; differences in compound nuclei formed with 40 Ar and 84 Kr projectiles; measurement of the energy division vs. mass in highly damped reactions; ambiguities in the inference of precompound emission from excitation function analysis; selective laser one-atom detection of neutral prompt fission fragments; laser induced nuclear polarization - application to the study of spontaneous fission isomers; quadrupole and hexadecapole deformations in the actinide nuclei; high-spin states in 164 Yb; contrasting behavior of h/sub 9/2/ and i/sub 13/2/ bands in 185 Au; multiple band crossings in 164 Er; recoil-distance measurement of lifetimes of rotational states in 164 Dy, lifetimes of ground-band states in 192 Pt and 194 Pt and application of the rotation-alignment model; coulomb excitation of vibrational nuclei with heavy ions; surface structure of deformed nuclei; valency contribution to neutron capture in 32 S; neutron capture cross section of manganese; search for superheavy elements in natural samples by neutron multiplicity counting; and gamma-ray studies on the geochemistry of achondritic meteorites

Soft tissue deformation modelling through neural dynamics-based reaction-diffusion mechanics.

Science.gov (United States)

Zhang, Jinao; Zhong, Yongmin; Gu, Chengfan

2018-05-30

Soft tissue deformation modelling forms the basis of development of surgical simulation, surgical planning and robotic-assisted minimally invasive surgery. This paper presents a new methodology for modelling of soft tissue deformation based on reaction-diffusion mechanics via neural dynamics. The potential energy stored in soft tissues due to a mechanical load to deform tissues away from their rest state is treated as the equivalent transmembrane potential energy, and it is distributed in the tissue masses in the manner of reaction-diffusion propagation of nonlinear electrical waves. The reaction-diffusion propagation of mechanical potential energy and nonrigid mechanics of motion are combined to model soft tissue deformation and its dynamics, both of which are further formulated as the dynamics of cellular neural networks to achieve real-time computational performance. The proposed methodology is implemented with a haptic device for interactive soft tissue deformation with force feedback. Experimental results demonstrate that the proposed methodology exhibits nonlinear force-displacement relationship for nonlinear soft tissue deformation. Homogeneous, anisotropic and heterogeneous soft tissue material properties can be modelled through the inherent physical properties of mass points. Graphical abstract Soft tissue deformation modelling with haptic feedback via neural dynamics-based reaction-diffusion mechanics.

Erratum to: Nuclear triaxiality in the A ∼ 160–170 mass region: the ...

Indian Academy of Sciences (India)

Erratum to: Nuclear triaxiality in the A ∼ 160–170 mass region: the story so far. S MUKHOPADHYAY1,∗ and W C MA2. 1Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India. 2Department of Physics, Mississippi State University, Mississippi State, Mississippi 39762, USA. ∗. Corresponding ...

The mechanical deformation of superconducting BiSrCaCuO/Ag composites

International Nuclear Information System (INIS)

Han, Z.; Skov-Hansen, P.; Freltoft, T.

1997-01-01

The mechanical deformation of BiSrCaCuO/Ag composites made by the powder-in-tube method is a multi-step process. The main difficulty is that the mechanical properties of the ceramic powder are very different from those of the Ag sheath. A key parameter is the core density, which changes during mechanical deformation. In this review, basic concepts of the classical mechanical deformation theory are briefly discussed. Simple descriptions of deformation processes like pressing, rolling, drawing and extrusion are also presented. The term 'freedom parameter', Δ f , is introduced to illustrate the influence of various constraint factors on the mass-flow behaviour. Simple pictures including mass redistribution and the powder-flow model are presented for interpreting the plastic deformation process of the composites. Experimental results are reviewed and our proposed pictures and models are applied for discussion. (author)

Ground-state properties of axially deformed Sr isotopes in Skyrme-Hartree-Fock-Bogolyubov method

International Nuclear Information System (INIS)

Yilmaz, A.H.; Bayram, T.; Demirci, M.; Engin, B.; Bayram, T.

2010-01-01

Binding energies, the mean-square nuclear radii, neutron radii, quadrupole moments and deformation parameters to axially deformed Strontium isotopes were evaluated using Hartree-Fock-Bogolyubov method. Shape coexistence was also discussed. The results were compared with experimental data and some estimates obtained within some nuclear models. The calculations were performed for SIy4 set of Skyrme forces and for wide range of the neutron numbers of Sr isotopes

Impact of thermal conductivity models on the coupling of heat transport, oxygen diffusion, and deformation in (U, Pu)O nuclear fuel elements

Science.gov (United States)

Mihaila, Bogdan; Stan, Marius; Crapps, Justin; Yun, Di

2013-02-01

We study the coupled thermal transport, oxygen diffusion, and thermal expansion in a generic nuclear fuel rod consisting of a (U) fuel pellet separated by a helium gap from zircaloy cladding. Steady-state and time-dependent finite-element simulations with a variety of initial- and boundary-value conditions are used to study the effect of the Pu content, y, and deviation from stoichiometry, x, on the temperature and deformation profiles in this fuel element. We find that the equilibrium radial temperature and deformation profiles are most sensitive to x at small values of y. For larger values of y, the effects of oxygen and Pu content are equally important. Following a change in the heat-generation rate, the centerline temperature, the radial deformation of the fuel pellet, and the centerline deviation from stoichiometry track each other closely in (U,Pu)O, as the characteristic time scales of the heat transport and oxygen diffusion are similar. This result is different from the situation observed in the case of UO fuels.

Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Plutonium by Controlled-Potential Coulometry Plutonium by Amperometric Titration with Iron(II) Plutonium by Diode Array Spectrophotometry Free Acid by Titration in an Oxalate Solution 8 to 15 Free Acid by Iodate Precipitation-Potentiometric Titration Test Method 16 to 22 Uranium by Arsenazo I Spectrophotometric Test Method 23 to 33 Thorium by Thorin Spectrophotometric Test Method 34 to 42 Iron by 1,10-Phenanthroline Spectrophotometric Test Method 43 to 50 Impurities by ICP-AES Chloride by Thiocyanate Spectrophotometric Test Method 51 to 58 Fluoride by Distillation-Spectrophotometric Test Method 59 to 66 Sulfate by Barium Sulfate Turbidimetric Test Method 67 to 74 Isotopic Composition by Mass Spectrom...

The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium

Energy Technology Data Exchange (ETDEWEB)

Ketelaer, Jens

2010-06-14

The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium: Nuclear masses are an important quantity to study nuclear structure since they reflect the sum of all nucleonic interactions. Many experimental possibilities exist to precisely measure masses, out of which the Penning trap is the tool to reach the highest precision. Moreover, absolute mass measurements can be performed using carbon, the atomic-mass standard, as a reference. The new double-Penning trap mass spectrometer TRIGA-TRAP has been installed and commissioned within this thesis work, which is the very first experimental setup of this kind located at a nuclear reactor. New technical developments have been carried out such as a reliable non-resonant laser ablation ion source for the production of carbon cluster ions and are still continued, like a non-destructive ion detection technique for single-ion measurements. Neutron-rich fission products will be available by the reactor that are important for nuclear astrophysics, especially the r-process. Prior to the on-line coupling to the reactor, TRIGA-TRAP already performed off-line mass measurements on stable and long-lived isotopes and will continue this program. The main focus within this thesis was on certain rare-earth nuclides in the well-established region of deformation around N {proportional_to} 90. Another field of interest are mass measurements on actinoids to test mass models and to provide direct links to the mass standard. Within this thesis, the mass of {sup 241}Am could be measured directly for the first time. (orig.)

The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium

International Nuclear Information System (INIS)

Ketelaer, Jens

2010-01-01

The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium: Nuclear masses are an important quantity to study nuclear structure since they reflect the sum of all nucleonic interactions. Many experimental possibilities exist to precisely measure masses, out of which the Penning trap is the tool to reach the highest precision. Moreover, absolute mass measurements can be performed using carbon, the atomic-mass standard, as a reference. The new double-Penning trap mass spectrometer TRIGA-TRAP has been installed and commissioned within this thesis work, which is the very first experimental setup of this kind located at a nuclear reactor. New technical developments have been carried out such as a reliable non-resonant laser ablation ion source for the production of carbon cluster ions and are still continued, like a non-destructive ion detection technique for single-ion measurements. Neutron-rich fission products will be available by the reactor that are important for nuclear astrophysics, especially the r-process. Prior to the on-line coupling to the reactor, TRIGA-TRAP already performed off-line mass measurements on stable and long-lived isotopes and will continue this program. The main focus within this thesis was on certain rare-earth nuclides in the well-established region of deformation around N ∝ 90. Another field of interest are mass measurements on actinoids to test mass models and to provide direct links to the mass standard. Within this thesis, the mass of 241 Am could be measured directly for the first time. (orig.)

Exotic octupole deformation in proton-rich Z=N nuclei

Energy Technology Data Exchange (ETDEWEB)

Takami, Satoshi; Yabana, K [Niigata Univ. (Japan); Matsuo, M

1998-03-01

We study static non-axial octupole deformations in proton-rich Z=N nuclei, {sup 64}Ge, {sup 68}Se, {sup 72}Kr, {sup 76}Sr, {sup 80}Zr and {sup 84}Mo, by using the Skyrme Hartree-Fock plus BCS method with no restrictions on the nuclear shape. The calculation predicts that the oblate ground state in {sup 68}Se is extremely soft for the Y{sub 33} triangular deformation, and that in {sup 80}Zr the low-lying local minimum state coexisting with the prolate ground state has the Y{sub 32} tetrahedral deformation. (author)

From the secrets of nuclear shapes into quantum nuclear phyics

International Nuclear Information System (INIS)

Dudek, J.

1988-01-01

After a few 'historical remarks' related to the evolution of our knowledge on nuclear shape effects, recent events in super-deformation studies are commented from the point of view of their general importance for nuclear physics. 12 refs

Transmission coefficents in strongly deformed nuclei

International Nuclear Information System (INIS)

Aleshin, V.P.

1996-01-01

By using our semiclassical approach to particle evaporation from deformed nuclei developed earlier, we analyze here the heuristic methods of taking into account the effects of shape deformations on particle emission. These methods are based on the 'local' transmission coefficients in which the effective barrier depends on the angle with respect to the symmetry axis. The calculations revealed that the heuristic models are reasonable for particle energy spectra but fail, at large deformations, to describe the angular distributions. In A∼160 nuclei with axis ratio in the vicinity of 2:1 at temperatures of 2-3 MeV, the W (90 )/W(0 ) anisotropies of α particles with respect to the nuclear spin are 1.5 to 3 times larger than our approach predicts. The influence of spin alignment on particle energy spectra is discussed shortly. (orig.)

Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse - CSNSM/Centre for nuclear and mass spectroscopy, Activity Report 2007-2009

International Nuclear Information System (INIS)

2010-01-01

The Centre for nuclear and mass spectroscopy (CSNSM) is a CNRS (National Centre for Scientific Research) laboratory affiliated with Paris-Sud University. The CSNSM is involved in pluri-disciplinary activities covering various scientific domains: Nuclear Structure (SNO), Nuclear Astrophysics (AN), Solid State Astrophysics (AS), Solid State Physics (PS) and Chemical Physics of Irradiation. This document presents the activity of the Centre during the 2007-2009 years: Nuclear Astrophysics; Solid State Astrophysics; Physics and Chemistry of Irradiation; Solid State Physics and cryogenic detectors; Solid State Physics, Condensed Matter and Irradiation; Structure of the Atomic Nucleus; Teaching and training activities; Spreading scientific culture; Administrative services; Electronics Group; Computer Department; Mechanics Department; RESET Service (Radiation-Environment-Safety- Maintenance-Work); SEMIRAMIS (ion source and ion beam handling)

Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse - CSNSM/Centre for nuclear and mass spectroscopy, Activity Report 2010-2012

International Nuclear Information System (INIS)

2013-07-01

The Centre for nuclear and mass spectroscopy (CSNSM) is a CNRS (National Centre for Scientific Research) laboratory affiliated with Paris-Sud University. The CSNSM is involved in pluri-disciplinary activities covering various scientific domains: Nuclear Structure (SNO), Nuclear Astrophysics (AN), Solid State Astrophysics (AS), Solid State Physics (PS) and Chemical Physics of Irradiation. This document presents the activity of the Centre during the 2010-2012 years: Nuclear Astrophysics; Solid State Astrophysics; Physics and Chemistry of Irradiation; Solid State Physics Group; Condensed Matter and Irradiation: from fundamental to functional; Structure of the Atomic Nucleus; Teaching activities; Spreading scientific culture; Administrative services; Electronics Group; Computer Department; Mechanics Department; RESET Service (Radiation-Environment-Safety- Maintenance-Work); SEMIRAMIS (ion source and ion beam handling)

SU(3) versus deformed Hartree-Fock state

International Nuclear Information System (INIS)

Johnson, Calvin W.; Stetcu, Ionel; Draayer, J.P.

2002-01-01

Deformation is fundamental to understanding nuclear structure. We compare two ways to efficiently realize deformation for many-fermion wave functions, the leading SU(3) irreducible representation and the angular-momentum-projected Hartree-Fock state. In the absence of single-particle spin-orbit splitting the two are nearly identical. With realistic forces, however, the difference between the two is nontrivial, with the angular-momentum-projected Hartree-Fock state better approximating an 'exact' wave function calculated in the fully interacting shell model. The difference is driven almost entirely by the single-particle spin-orbit splitting

Mass media differences in ''nuclear news'' reporting: implications for public opinions and acceptable safeguards

International Nuclear Information System (INIS)

Williams, A.; Williams, J.

1975-01-01

The technical and political issues of diversion safeguards are at best confusing to the general public, who derive most of their information about nuclear science from the mass media. This investigation compared ''nuclear news'' of all kinds in three national mass media for thirty-three months of 1972-1974 to examine the quantity and quality of atom-related news they provide. Findings from The New York Times, U. S. News and World Report, and the ABC, CBS, and NBC evening news indicate grounds for low public familiarity with essential concepts of safeguards, and consequently, for consumer value conflicts and weak popular supports for safeguards-related policy

Differential calculus for q-deformed twistors

International Nuclear Information System (INIS)

Akulov, V.P.; Duplij, S.A.; Chitov, V.V.

1998-01-01

Brief type of q-deformed differential calculus at light cone with using of twistor representation is suggested. Commutative relations between coordinates and moments are obtained. Considered quasiclassical limit gives exact form of vanish from mass shell

Importance of banked tissues in the management of mass nuclear casualties

International Nuclear Information System (INIS)

Singh, Rita; Bhatnagar, P.K.

2009-01-01

Nuclear detonations are the most devastating of the weapons of mass destruction. There will be large number of casualties on detonation of nuclear weapon. Biological tissues like bone, skin, amniotic membrane and other soft tissues can be used for repair or reconstruction of the injured part of the body. Tissues from human donor can be processed and banked for orthopaedic, spinal, trauma and other surgical procedures. Radiation technology is used to sterilize the tissues to make them safe for clinical use. This paper highlights the importance of such banked tissues in the management of the casualties. (author)

Coupled deformation and fluid-flow behavior of a natural fracture in the CSM in situ test block

International Nuclear Information System (INIS)

Gertsch, L.S.

1989-01-01

The primary goal was the evaluation of an in situ block test as a data source for modeling the coupled flow and mechanical behavior of natural rock fractures. The experiments were conducted with the Colorado School of Mines in situ test block, an 8 m 3 (280 ft 3 ) gneiss cube which has been the focus of several previous studies. A single continuous fracture within the block was surrounded with instruments to measure stresses, deformations, and gas conductivity. The setup was subjected to combinations of normal and shear stress by pressurizing the block sides differentially with hydraulic flatjacks. The induced fracture deformation, as measured by two separate sensor systems, did not correlate closely with the fracture conductivity changes or with each other. The test fracture is more complicated physically than two parallel rock faces. Many joints which were not detected by mapping intersect the test fracture and strongly influence its behavior. These invisible joints create sub-blocks which react complexly to changes in applied load. The flow tests reflected the aggregate sub-block dislocations in the flow path. The deformation readings, however, were the movements of discrete points sparsely located among the sub-blocks. High-confidence extrapolation of block test results to large volumes, such as required for nuclear waste repository design, is not feasible currently. Present instrumentation does not sample rock mass behavior in situ at the proper scales. More basically, however, a fundamental gap exists between the nature of jointed rock and our conception of it. Therefore, the near-field rock mass must be discounted as an easily controllable barrier to groundwater flow, until radically different approaches to rock mass testing and modeling are developed

Accelerator Mass Spectrometry at the Nuclear Science Laboratory: Applications to Nuclear Astrophysics

Science.gov (United States)

Collon, P.; Bauder, W.; Bowers, M.; Lu, W.; Ostdiek, K.; Robertson, D.

The Accelerator Mass Spectrometry (AMS) program at the Nuclear Science Laboratory of the University of Notre Dame is focused on measurements related to galactic radioactivity and to nucleosynthesis of main stellar burning as well as the production of so called Short-Lived Radionuclides (SLRs) in the Early Solar System (ESS). The research program is based around the 11MV FN tandem accelerator and the use of the gas-filled magnet technique for isobar separation. Using a technique that evolved from radiocarbon dating, this paper presents a number of research programs that rely on the use of an 11MV tandem accelerator at the center of the AMS program.

A version of the Quasiparticle-Phonon Nuclear Model for doubly-even well-deformed nuclei

International Nuclear Information System (INIS)

Soloviev, V.G.

1992-06-01

The basic assumptions concerning the Quasiparticle-Phonon Nuclear Model are formulated and the mathematical apparatus is developed. The Hamiltonian, containing a finite-rank separable isoscalar and isovector multipole, a spin-multipole and a tensor particle-hole as well as particle-particle interactions transforms to a form containing quasiparticle, phonon and quasiparticle-phonon interactions. The general RPA equation is derived and the particular cases are discussed. The very complex interaction does not complicate the description of the fragmentation one-phonon states. It is shown that the three-phonon terms added to the one- and two-phonon terms in the wave function lead to an additional small shift of the two-phonon poles in the secular equation. The influence of the density-dependent separable interaction on the vibrational states is small. A common description of the collective, weakly collective and two-quasiparticle states in doubly-even well-deformed nuclei is obtained. (author)

Strong electric and magnetic dipole excitations in deformed nuclei

International Nuclear Information System (INIS)

Kneissl, U.

1993-01-01

Systematic nuclear resonance fluorescence (NRF) experiments have been performed at the bremsstrahlung facility of the Stutgart dynamitron to investigate the distribution of magnetic and electric dipole excitations in deformed nuclei

Nuclear Forensics: Measurements of Uranium Oxides Using Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS)

Science.gov (United States)

2010-03-01

Isotope Ratio Analysis of Actinides , Fission Products, and Geolocators by High- efficiency Multi-collector Thermal Ionization Mass Spectrometry...Information, 1999. Hou, Xiaolin, and Per Roos. “ Critical Comparison of radiometric and Mass Spectrometric Methods for the Determination of...NUCLEAR FORENSICS: MEASUREMENTS OF URANIUM OXIDES USING TIME-OF-FLIGHT SECONDARY ION MASS

Administrative Procedure Act and mass procedures (illustrated by the nuclear licensing procedure)

International Nuclear Information System (INIS)

Naumann, R.

1977-01-01

The report deals with the administrative procedure law of 25.5.76 of the Fed. Government, esp. with its meaning for the administrative procedures for the permission for nuclear power plants, as fas ar so-called mass procedures are concerned. (UN) [de

The nuclear deformation versus the spin-flip like excitations and the suppression of the 2νββ decay amplitude

International Nuclear Information System (INIS)

Raduta, A.A.; Delion, D.S.; Faessler, A.

1997-01-01

The suppression mechanism of the Gamow-Teller double beta decay amplitude M GT is studied using a many body Hamiltonian which describes a composite system of protons and neutrons moving in a projected spherical single particle basis. Alike nucleons interact through pairing while protons and neutrons by a separable dipole-dipole force both in the particle-hole (ph) and particle-particle (pp) channels. The spin-flip and non-spin-flip components of the QRPA phonons have a differents contribution to the M GT values. The relative magnitudes and phases depend both on the strength of the particle-particle interaction (g pp ) and on the nuclear deformation. The deformation yields a fragmentation of the M GT value on one hand and washes out the separation of states of pure spin-flip and non-spin-flip structures. Due to this effect M GT has only one fragmented resonance structure in the low part of the spectrum. (orig.)

The nuclear flow and the mass number dependence of the balance point

International Nuclear Information System (INIS)

Sebille, F.; de la Mota, V.; Remaud, B.; Schuck, P.

1990-01-01

The nuclear flow is studied theoretically with the Landau Vlasov equation in the E/A = 50 to 150 MeV energy domain using the finite range Gogny force. For comparison also other equations of states based on velocity independent mean fields are used. In this paper the mass number dependence of the balance point is investigated. A sensitivity of the flow on the equation of state as a function of mass and energies around and above the balance point can tentatively be advanced

Nuclear level density of 166Er with static deformation

International Nuclear Information System (INIS)

Nasrabadi, M.N.

2006-01-01

The level densities of 166 Er is calculated using the microscopic theory of interacting fermions and is compared with experimental. It is concluded that the data can be reproduced with level density formalism for nuclei with static deformation

Intruder states, coexistence, and approaches to deformation: The study of 120Xe and the N = 66 isotones

International Nuclear Information System (INIS)

Mantica, P.F. Jr.; Zimmerman, B.E.; Ford, C.E.; Walters, W.B.; Rikovska, J.; Stone, N.J.

1989-01-01

In this chapter, new results of γ-ray and conversion-electron spectroscopic studies of the structure of 119,121 Te and 126,127 Xe will be reported. These results will be described along with the results of previous studies of intruder structures in the Te and Xe mass region. The observed structures will be contrasted with other intruder structure identified in the Sn, Cd, and Pd isotopes. Results of IBM mixing calculations will be shown for the even-even Te nuclides. The role of intruder structures in the development of nuclear deformation will be discussed. 52 refs., 8 figs., 1 tab

Regional regularities for the even-even nuclei in intermediate mass region

International Nuclear Information System (INIS)

Varshney, Mani; Singh, M.; Gupta, D.K.; Singh, Yuvraj; Gupta, K.K.; Bihari, Chhail; Sharma, Aparna; Varshney, A.K.

2011-01-01

With the development of experimental techniques more and more nuclear data are accumulated and compiled for over five decades. The proton neutron interaction has been considered the key ingredient in the development of collectivity and ultimately the deformation in atomic nuclei. The purpose of the present study is to analyze the growth of R4/2 in different mass regions. The rate of growth regions in regions having proton number Z = 38, 54, 60 and 76 with changing neutron number where the interaction between particle - particle, particle - hole and hole - hole

Deformed supersymmetric mechanics

International Nuclear Information System (INIS)

Ivanov, E.; Sidorov, S.

2013-01-01

Motivated by a recent interest in curved rigid supersymmetries, we construct a new type of N = 4, d = 1 supersymmetric systems by employing superfields defined on the cosets of the supergroup SU(2|1). The relevant worldline supersymmetry is a deformation of the standard N = 4, d = 1 supersymmetry by a mass parameter m. As instructive examples we consider at the classical and quantum levels the models associated with the supermultiplets (1,4,3) and (2,4,2) and find out interesting interrelations with some previous works on nonstandard d = 1 supersymmetry. In particular, the d = 1 systems with 'weak supersymmetry' are naturally reproduced within our SU(2|1) superfield approach as a subclass of the (1,4,3) models. A generalization to the N = 8, d = 1 case implies the supergroup SU(2|2) as a candidate deformed worldline supersymmetry

Evaluation method for the deformation of channel box

International Nuclear Information System (INIS)

Sadaoka, Noriyuki; Kumahora, Hiroki; Miki, Kazuyoshi.

1990-01-01

In a BWR type nuclear reactor, a channel box undergoes creep deformation due to the effects of a pressure difference between inside and outside of the channel box and a reactor water temperature, which is accelerated by the irradiation of radiation rays and the extent of which depends on the loading position. Then, there are provided a step of determining the extent of the deformation of the channel box in a burning period in the past, a step of setting the loading position for the channel box in the reactor core, a step of forecasting the extent of the deformation of the channel box based on the data of reactor core characteristics, the date of the physical properties of the materials and the shape of the channel box, the data of the loading pattern of fuel assemblies and the extent of deformation, and a step of estimating whether the forecast deforming extent is within an allowable range or not. As a result, the deforming extent for each of the channel boxes can be forecast and, accordingly, the interference with the control rods can be estimated accurately. (N.H.)

Nuclear Chemistry Project. Progress report, Janary 1, 1979-December 31, 1979

International Nuclear Information System (INIS)

1979-01-01

The first on-line operation of the Princeton electron spectrometer was achieved and its capability for fast life time measurements demonstrated. The first operation of the heavy ion source was achieved and beams of 75 meV 12 C +4 ions and 37 MeV 6 Li +2 ions demonstrated. The capability of the isotope separator to provide pure mass separated samples of radioisotopes is being utilized for three different applications. The very weak electron capture branch of 19-s krypton 81m to bromine 81 was studied. This transition probability is of crucial importance for a possible solar neutrino detection method based on natural bromine. Lead 202 has been prepared and mass separated for optical hyperfine spectroscopic studies. The isotope shift shift which measures the second moment, 2 >, of the nuclear charge indicates the more neutron deficient lead isotopes are becoming increasingly soft toward nuclear deformation

EMPIRE-II statistical model code for nuclear reaction calculations

Energy Technology Data Exchange (ETDEWEB)

Herman, M [International Atomic Energy Agency, Vienna (Austria)

2001-12-15

EMPIRE II is a nuclear reaction code, comprising various nuclear models, and designed for calculations in the broad range of energies and incident particles. A projectile can be any nucleon or Heavy Ion. The energy range starts just above the resonance region, in the case of neutron projectile, and extends up to few hundreds of MeV for Heavy Ion induced reactions. The code accounts for the major nuclear reaction mechanisms, such as optical model (SCATB), Multistep Direct (ORION + TRISTAN), NVWY Multistep Compound, and the full featured Hauser-Feshbach model. Heavy Ion fusion cross section can be calculated within the simplified coupled channels approach (CCFUS). A comprehensive library of input parameters covers nuclear masses, optical model parameters, ground state deformations, discrete levels and decay schemes, level densities, fission barriers (BARFIT), moments of inertia (MOMFIT), and {gamma}-ray strength functions. Effects of the dynamic deformation of a fast rotating nucleus can be taken into account in the calculations. The results can be converted into the ENDF-VI format using the accompanying code EMPEND. The package contains the full EXFOR library of experimental data. Relevant EXFOR entries are automatically retrieved during the calculations. Plots comparing experimental results with the calculated ones can be produced using X4TOC4 and PLOTC4 codes linked to the rest of the system through bash-shell (UNIX) scripts. The graphic user interface written in Tcl/Tk is provided. (author)

The tensile deformation behavior of nuclear-grade isotropic graphite posterior to hydrostatic loading

International Nuclear Information System (INIS)

Yoda, S.; Eto, M.

1983-01-01

The effects of prehydrostatic loading on microstructural changes and tensile deformation behavior of nuclear-grade isotropic graphite have been examined. Scanning electron micrographs show that formation of microcracks associated with delamination between basal planes occurs under hydrostatic loading. Hydrostatic loading on specimens results in the decrease in tensile strength and increase in residual strain generated by the applied tensile stress at various levels, indicating that the graphite material is weakened by hydrostatic loading. A relationship between residual strain and applied tensile stress for graphite hydrostatically-loaded at several pressure levels can be approximately expressed as element of= (AP + B) sigmasup(n) over a wide range hydrostatic pressure, where element of, P and sigma denote residual strain, hydrostatic pressure and applied tensile stress, respectively; A, B and n are constant. The effects of prehydrostatic loading on the tensile stress-strain behavior of the graphite were examined in more detail. The ratio of stress after hydrostatic loading to that before hydrostatic loading on the stress-strain relationship remains almost unchanged irrespective of strain. (orig.)

Nuclear-mass dependence of azimuthal beam-helicity and beam-charge asymmetries in deeply virtual Compton scattering

International Nuclear Information System (INIS)

Airapetian, A.; Akopov, Z.

2009-11-01

The nuclear-mass dependence of azimuthal cross section asymmetries with respect to charge and longitudinal polarization of the lepton beam is studied for hard exclusive electroproduction of real photons. The observed beam-charge and beam-helicity asymmetries are attributed to the interference between the Bethe-Heitler and deeply virtual Compton scattering processes. For various nuclei, the asymmetries are extracted for both coherent and incoherent-enriched regions, which involve different (combinations of) generalized parton distributions. For both regions, the asymmetries are compared to those for a free proton, and no nuclear-mass dependence is found. (orig.)

Numerical Modeling of Subglacial Sediment Deformation

DEFF Research Database (Denmark)

Damsgaard, Anders

2015-01-01

may cause mass loss in the near future to exceed current best estimates. Ice flow in larger ice sheets focuses in fast-moving streams due to mechanical non-linearity of ice. These ice streams often move at velocities several magnitudes larger than surrounding ice and consequentially constitute...... glaciers move by deforming their sedimentary beds. Several modern ice streams, in particular, move as plug flows due to basal sediment deformation. An intense and long-winded discussion about the appropriate description for subglacial sediment mechanics followed this discovery, with good reason...... incompatible with commonly accepted till rheology models. Variation in pore-water pressure proves to cause reorganization in the internal stress network and leads to slow creeping deformation. The rate of creep is non-linearly dependent on the applied stresses. Granular creep can explain slow glacial...

EFFECT OF CENTRAL MASS CONCENTRATION ON THE FORMATION OF NUCLEAR SPIRALS IN BARRED GALAXIES

International Nuclear Information System (INIS)

Thakur, Parijat; Jiang, I.-G.; Ann, H. B.

2009-01-01

We have performed smoothed particle hydrodynamics simulations to study the response of the central kiloparsec region of a gaseous disk to the imposition of nonaxisymmetric bar potentials. The model galaxies are composed of three axisymmetric components (halo, disk, and bulge) and a nonaxisymmetric bar. These components are assumed to be invariant in time in the frame corotating with the bar. The potential of spherical γ-models of Dehnen is adopted for the bulge component whose density varies as r -γ near the center and r -4 at larger radii and, hence, possesses a central density core for γ = 0 and cusps for γ>0. Since the central mass concentration of the model galaxies increases with the cusp parameter γ, we have examined here the effect of the central mass concentration by varying the cusp parameter γ on the mechanism responsible for the formation of the symmetric two-armed nuclear spirals in barred galaxies. Our simulations show that the symmetric two-armed nuclear spirals are formed by hydrodynamic spiral shocks driven by the gravitational torque of the bar for the models with γ = 0 and 0.5. On the other hand, the symmetric two-armed nuclear spirals in the models with γ = 1 and 1.5 are explained by gas density waves. Thus, we conclude that the mechanism responsible for the formation of symmetric two-armed nuclear spirals in barred galaxies changes from hydrodynamic shocks to gas density waves as the central mass concentration increases from γ = 0 to 1.5.

Elimination of acoustical phonons by mass deformation

International Nuclear Information System (INIS)

Djajic, R.P.; Setrajcic, J.P.; Tosic, B.S.; Mirjanic, D.L.

1987-01-01

Cubic structure with well expressed anisotropy along one direction was analyzed. Lattice constant along z - direction is few times bigger than the planar lattice constants. If we sputter into such structure and introduce foreign atoms, it is energetically most convenient if they locate themselves along the z - axis. Basic assumption of this model is that clusters form on the boundary layers of the matrix, and that their size decreases with the depth of the structure, and consequently the reduced mass increases width the depth of the structure as well. At the center of the matrix, clusters do not form, and reduced mass is equal to μ m i.e. the mass of the molecule of the matrix

Investigation of an orbital mass - the role of nuclear medicine

International Nuclear Information System (INIS)

Dunlop, R. V.

2009-01-01

Full text:A 35 year old male presented, suffering from night sweats, occipital and frontal headaches, blurred vision, nausea and a decrease in appetite. He underwent a CT and MRI scan, which identified a 2.2cm lesion in the left orbit in an intra-conal position. This was suspected to be a cavernous haemangioma, although other tumours, such as Schwannoma could not be ruled out. A nuclear medicine labelled red blood cell study was performed which included initial dynamic images and early statics and 120min delayed images. SPECT/CT was also performed at the later time. The characteristic blood pool mismatch of low early and high delayed concentration of red blood cells confirmed suspicions of a cavernous haemangioma, which, although comprised mainly of blood vessels, has slow flow. Hence there is considerable delay before maximum activity is reached. The lesion was surgically removed. Histology reports confirmed the nuclear medicine results. Nuclear Medicine has the potential to play a significant role in the preoperative diagnosis of an orbital mass.

Exotic nuclear structures and decays: new nuclear collective phenomena

International Nuclear Information System (INIS)

Hamilton, J.H.

1986-01-01

Studies of the properties of exotic nuclei have revealed a surprising richness and diversity in their shapes, structures, and decay modes far exceeding our understandings and expectations of even a decay ago. From studies of far-off-stability exotic nuclei have come evidence for the coexistence of different nuclear shapes in the same nucleus, new regions of unusually large deformation, new ground-state phase transitions from one shape to another, new magic numbers but now for deformed shapes, and for the importance of reinforcing shell gaps. New exotic decay modes include a wide variety of beta delayed particle emission and heavy cluster emissions such as 14 C and 24 Ne. The new deformed magic numbers of 38 and 60 seen far off stability clearly support that there are likely other ''magic'' numbers for protons and neutrons which give stability to different deformed shapes. Perhaps these other new magic shell gap numbers at large deformation could influence the sticking of two very heavy nuclei in collisions such as U on Cm. Finally, another area which could have a bearing on the formation, motions, and structures of giant nuclear systems involves the recent observation of very energetic, light particle (proton, alpha) emission with up to 50% and more of the total incoming energy in a collision, for example in 300 MeV 32 S on Ta. 43 refs., 11 figs., 2 tabs

Relativistic mean field theory for deformed nuclei with pairing correlations

International Nuclear Information System (INIS)

Geng, Lisheng; Toki, Hiroshi; Sugimoto, Satoru; Meng, Jie

2003-01-01

We develop a relativistic mean field (RMF) description of deformed nuclei with pairing correlations in the BCS approximation. The treatment of the pairing correlations for nuclei whose Fermi surfaces are close to the threshold of unbound states needs special attention. With this in mind, we use a delta function interaction for the pairing interaction to pick up those states whose wave functions are concentrated in the nuclear region and employ the standard BCS approximation for the single-particle states obtained from the BMF theory with deformation. We apply the RMF + BCS method to the Zr isotopes and obtain a good description of the binding energies and the nuclear radii of nuclei from the proton drip line to the neutron drip line. (author)

Investigations of nuclear structure and nuclear reactions induced by complex projectiles

International Nuclear Information System (INIS)

Sarantites, D.G.

1992-01-01

The research program described touches five areas of nuclear physics: nuclear structure studies at high spin (hyperdeformation in the mass A ≅ 182 region, structure of 182 Hg and 182 Au at high spin, a highly deformed band in 136 Pm and the anomalous h 11/2 proton crossing in the A∼135 superdeformed region), studies at the interface between structure and reactions (population of entry states in heavy-ion fusion reactions, nuclear structure effects in proton evaporation spectra, nuclear structure- dependent entry state population by total spectroscopy, entrance channel effects in fusion near the barrier, lifetimes of subbarrier α particles by the atomic clock method), production and study of hot nuclei (the statistical model evaporation code EVAP, statistical emission of deuterons and tritons from highly excited compound nuclei, heavy-fragment emission as a probe of the thermal properties of highly excited compound nuclei, use of incoming-wave boundary condition transmission coefficients in the statistical model: implications in the particle evaporation spectra, study of transparency in the optical model), reaction mechanism studies (binary character of highly dissipative 209 Bi + 136 Xe collisions at E/A=28.2 MeV), and development and use of novel techniques and instrumentation in these areas of research (including a 4π channel selection device, a novel x-ray detector, and a simple channel-selecting detector)

Deformations of fractured rock

International Nuclear Information System (INIS)

Stephansson, O.

1977-09-01

Results of the DBM and FEM analysis in this study indicate that a suitable rock mass for repository of radioactive waste should be moderately jointed (about 1 joint/m 2 ) and surrounded by shear zones of the first order. This allowes for a gentle and flexible deformation under tectonic stresses and prevent the development of large cross-cutting failures in the repository area. (author)

Woods-Saxon potential parametrization at large deformations for plutonium odd isotopes

International Nuclear Information System (INIS)

Garcia, F.; Garrote, E.; Yoneama, M.L.; Arruda-Neto, J.D.T.; Mesa, J.; Bringas, F.; Likhachev, V.P.; Rodriguez, O.; Guzman, F.

1999-01-01

The structure of single-particle levels in the second minima of 237,239,241 Pu was analyzed with the help of an axially-deformed Woods-Saxon potential. The nuclear shape was parametrized in terms of the cassinian ovaloids. A parametrization of the spin-orbit part of the potential was obtained in the region corresponding to large deformations (second minimum), depending only on the nuclear surface area. With this parametrization, we were able to reproduce successfully the spin, parity and energies of the rotational band built on the 8 μ s isomeric state in 239 Pu and, also, a spin assignment for both isomeric states in 237 Pu and 241 Pu was carried out. (orig.)

Random matrices and chaos in nuclear physics: Nuclear structure

International Nuclear Information System (INIS)

Weidenmueller, H. A.; Mitchell, G. E.

2009-01-01

Evidence for the applicability of random-matrix theory to nuclear spectra is reviewed. In analogy to systems with few degrees of freedom, one speaks of chaos (more accurately, quantum chaos) in nuclei whenever random-matrix predictions are fulfilled. An introduction into the basic concepts of random-matrix theory is followed by a survey over the extant experimental information on spectral fluctuations, including a discussion of the violation of a symmetry or invariance property. Chaos in nuclear models is discussed for the spherical shell model, for the deformed shell model, and for the interacting boson model. Evidence for chaos also comes from random-matrix ensembles patterned after the shell model such as the embedded two-body ensemble, the two-body random ensemble, and the constrained ensembles. All this evidence points to the fact that chaos is a generic property of nuclear spectra, except for the ground-state regions of strongly deformed nuclei.

Identification of highly deformed even–even nuclei in the neutron- and proton-rich regions of the nuclear chart from the B(E2)↑ and E2 predictions in the generalized differential equation model

International Nuclear Information System (INIS)

Nayak, R.C.; Pattnaik, S.

2015-01-01

We identify here the possible occurrence of large deformations in the neutron- and proton-rich (n-rich and p-rich) regions of the nuclear chart from extensive predictions of the values of the reduced quadrupole transition probability B(E2)↑ for the transition from the ground state to the first 2 + state and the corresponding excitation energy E2 of even–even nuclei in the recently developed generalized differential equation (GDE) model exclusively meant for these physical quantities. This is made possible from our analysis of the predicted values of these two physical quantities and the corresponding deformation parameters derived from them such as the quadrupole deformation β 2 , the ratio of β- 2 to the Weisskopf single-particle β 2(sp) and the intrinsic electric quadrupole moment Q 0 , calculated for a large number of both known as well as hitherto unknown even–even isotopes of oxygen to fermium (0 to FM; Z = 8 – 100). Our critical analysis of the resulting data convincingly support possible existence of large collectivity for the nuclides 30,32 Ne, 34 Mg, 60 Ti, 42,62,64 Cr, 50,68 Fe, 52,72 Ni, 72,70,96 Kr, 74,76 Sr, 78,80,106,108 Zr, 82,84,110,112 Mo, 140 Te, 144 Xe, 148 Ba, 122 Ce, 128,156 Nd, 130,132,158,160 Sm and 138,162,164,166 Gd, whose values of β 2 are found to exceed 0.3 and even 0.4 in some cases. Our findings of large deformations in the exotic n-rich regions support the existence of another “island of inversion” in the heavy-mass region possibly caused by breaking of the N = 70 subshell closure. (author)

Fine structure in deformed proton emitting nuclei

International Nuclear Information System (INIS)

Sonzogni, A. A.; Davids, C. N.; Woods, P. J.; Seweryniak, D.; Carpenter, M. P.; Ressler, J. J.; Schwartz, J.; Uusitalo, J.; Walters, W. B.

1999-01-01

In a recent experiment to study the proton radioactivity of the highly deformed 131 Eu nucleus, two proton lines were detected. The higher energy one was assigned to the ground-state to ground-state decay, while the lower energy, to the ground-state to the 2 + state decay. This constitutes the first observation of fine structure in proton radioactivity. With these four measured quantities, proton energies, half-life and branching ratio, it is possible to determine the Nilsson configuration of the ground state of the proton emitting nucleus as well as the 2 + energy and nuclear deformation of the daughter nucleus. These results will be presented and discussed

Neutron-Proton Mass Difference in Nuclear Matter and in Finite Nuclei and the Nolen-Schiffer Anomaly

Directory of Open Access Journals (Sweden)

Yakhshiev U.T.

2010-04-01

Full Text Available The neutron-proton mass difference in (isospin asymmetric nuclear matter and finite nuclei is studied in the framework of a medium-modified Skyrme model. The proposed effective Lagrangian incorporates both the medium influence of the surrounding nuclear environment on the single nucleon properties and an explicit isospin-breaking effect in the mesonic sector. Energy-dependent charged and neutral pion optical potentials in the s- and p-wave channels are included as well. The present approach predicts that the neutron-proton mass difference is mainly dictated by its strong part and that it markedly decreases in neutron matter. Furthermore, the possible interplay between the effective nucleon mass in finite nuclei and the Nolen-Schiffer anomaly is discussed. In particular, we find that a correct description of the properties of mirror nuclei leads to a stringent restriction of possible modifications of the nucleon’s effective mass in nuclei.

Charge-exchange QRPA with the Gogny Force for Axially-symmetric Deformed Nuclei

Energy Technology Data Exchange (ETDEWEB)

Martini, M., E-mail: martini.marco@gmail.com [Institut d' Astronomie et d' Astrophysique, Université Libre de Bruxelles, CP-226, 1050 Brussels (Belgium); CEA, DAM, DIF, F-91297 Arpajon (France); Goriely, S. [Institut d' Astronomie et d' Astrophysique, Université Libre de Bruxelles, CP-226, 1050 Brussels (Belgium); Péru, S. [CEA, DAM, DIF, F-91297 Arpajon (France)

2014-06-15

In recent years fully consistent quasiparticle random-phase approximation (QRPA) calculations using finite range Gogny force have been performed to study electromagnetic excitations of several axially-symmetric deformed nuclei up to the {sup 238}U. Here we present the extension of this approach to the charge-exchange nuclear excitations (pnQRPA). In particular we focus on the Isobaric Analog and Gamow-Teller resonances. A comparison of the predicted GT strength distribution with existing experimental data is presented. The role of nuclear deformation is shown. Special attention is paid to β-decay half-lives calculations for which experimental data exist and for specific isotone chains of relevance for the r-process nucleosynthesis.

SURFACE SYMMETRY ENERGY OF NUCLEAR ENERGY DENSITY FUNCTIONALS

Energy Technology Data Exchange (ETDEWEB)

Nikolov, N; Schunck, N; Nazarewicz, W; Bender, M; Pei, J

2010-12-20

We study the bulk deformation properties of the Skyrme nuclear energy density functionals. Following simple arguments based on the leptodermous expansion and liquid drop model, we apply the nuclear density functional theory to assess the role of the surface symmetry energy in nuclei. To this end, we validate the commonly used functional parametrizations against the data on excitation energies of superdeformed band-heads in Hg and Pb isotopes, and fission isomers in actinide nuclei. After subtracting shell effects, the results of our self-consistent calculations are consistent with macroscopic arguments and indicate that experimental data on strongly deformed configurations in neutron-rich nuclei are essential for optimizing future nuclear energy density functionals. The resulting survey provides a useful benchmark for further theoretical improvements. Unlike in nuclei close to the stability valley, whose macroscopic deformability hangs on the balance of surface and Coulomb terms, the deformability of neutron-rich nuclei strongly depends on the surface-symmetry energy; hence, its proper determination is crucial for the stability of deformed phases of the neutron-rich matter and description of fission rates for r-process nucleosynthesis.

Nuclear fuel element

International Nuclear Information System (INIS)

Yamamoto, Seigoro.

1994-01-01

Ultrafine particles of a thermal neutron absorber showing ultraplasticity is dispersed in oxide ceramic fuels by more than 1% to 10% or lower. The ultrafine particles of the thermal neutron absorber showing ultrafine plasticity is selected from any one of ZrGd, HfEu, HfY, HfGd, ZrEu, and ZrY. The thermal neutron absorber is converted into ultrafine particles and solid-solubilized in a nuclear fuel pellet, so that the dispersion thereof into nuclear fuels is made uniform and an absorbing performance of the thermal neutrons is also made uniform. Moreover, the characteristics thereof, for example, physical properties such as expansion coefficient and thermal conductivity of the nuclear fuels are also improved. The neutron absorber, such as ZrGd or the like, can provide plasticity of nuclear fuels, if it is mixed into the nuclear fuels for showing the plasticity. The nuclear fuel pellets are deformed like an hour glass as burning, but, since the end portion thereof is deformed plastically within a range of a repulsive force of the cladding tube, there is no worry of damaging a portion of the cladding tube. (N.H.)

Low mass dilepton production at the SPS probing hot and dense nuclear matter

CERN Document Server

Pérez de los Heros, C; Baur, R; Breskin, Amos; Chechik, R; Drees, A; Jacob, C; Faschingbauer, U; Fisher, P H; Fraenkel, Zeev; Fuchs, C; Gatti, E; Glässel, P; Günzel, T F; Hess, F; Irmscher, D; Lenkeit, B C; Olsen, L H; Panebratsev, Yu A; Pfeiffer, A; Ravinovich, I; Rehak, P; Schön, A; Schükraft, Jürgen; Sampietro, M; Shimansky, S S; Shor, A; Specht, H J; Steiner, V; Tapprogge, Stefan; Tel-Zur, G; Tserruya, Itzhak; Ullrich, T S; Wurm, J P; Yurevich, V I

1996-01-01

CERES and HELIOS-3 have detected a significant enhancement of low--mass dileptons in nuclear collisions at 200 GeV/nucleon with respect to the expected ``conventional'' sources. The onset of the excess, starting at a mass of $\\sim2m_{\\pi}$, and the possibility of a quadratic dependence on the event multiplicity suggest the opening of the $\\pi^+\\pi^-\\rightarrow e^+e^-(\\mu^+\\mu^-)$ annihilation channel. This would be the first observation of thermal radiation from dense hadronic matter. Possible interpretations of these results are presented, including the reduction of the $\\rho$ mass due to partial restoration of chiral symmetry in the dense fireball formed in the collision.

Investigative study of the underground excavations for a nuclear waste repository in tuff: Nevada Nuclear Waste Storage Investigations Project

International Nuclear Information System (INIS)

St John, C.M.

1987-07-01

Numerical studies were conducted on the behavior of a tuff rock mass within which emplacement drifts for a nuclear waste repository are excavated. The first study evaluated the effects of rockbolting and excavation-induced damage on the behavior of the rock mass round typical drifts. The second study provided a simple means of assessing the significance of drift shape, drift size, and in-situ state of stress on the deformation and stress in the vicinity of drifts for vertical and horizontal emplacement of waste. Neither study considered the effect of heating of the rock mass after emplacement of the waste so the conclusions pertain only to the conditions immediately after excavation of the underground openings. The results of analyses of the rockbolted excavations indicated that rockbolts do not have a significant influence on the states of deformation or stress within the rock mass, and that the rockbolts are subjected to acceptable levels of stress even if installed as close to the face of the excavation as possible. Accordingly, rockbolts were not considered in the study of drift shape, drift size, and the in-situ state of stress. That study indicated that stable openings of the dimensions investigated can be constructed within a tuff rock mass with the properties assumed. Of the parameters investigated, the in-situ state of stress appeared to be most important. Potentially adverse conditions were predicted if the in-situ horizontal stress is very low, but current indications are that it lies within a range which is consistent with good conditions and a stable roof. 28 refs., 49 figs., 11 tabs

Anisotropy of strength and deformability of fractured rocks

Directory of Open Access Journals (Sweden)

Majid Noorian Bidgoli

2014-04-01

Full Text Available Anisotropy of the strength and deformation behaviors of fractured rock masses is a crucial issue for design and stability assessments of rock engineering structures, due mainly to the non-uniform and non-regular geometries of the fracture systems. However, no adequate efforts have been made to study this issue due to the current practical impossibility of laboratory tests with samples of large volumes containing many fractures, and the difficulty for controlling reliable initial and boundary conditions for large-scale in situ tests. Therefore, a reliable numerical predicting approach for evaluating anisotropy of fractured rock masses is needed. The objective of this study is to systematically investigate anisotropy of strength and deformability of fractured rocks, which has not been conducted in the past, using a numerical modeling method. A series of realistic two-dimensional (2D discrete fracture network (DFN models were established based on site investigation data, which were then loaded in different directions, using the code UDEC of discrete element method (DEM, with changing confining pressures. Numerical results show that strength envelopes and elastic deformability parameters of tested numerical models are significantly anisotropic, and vary with changing axial loading and confining pressures. The results indicate that for design and safety assessments of rock engineering projects, the directional variations of strength and deformability of the fractured rock mass concerned must be treated properly with respect to the directions of in situ stresses. Traditional practice for simply positioning axial orientation of tunnels in association with principal stress directions only may not be adequate for safety requirements. Outstanding issues of the present study and suggestions for future study are also presented.

First Direct Mass Measurements of Nuclides around Z =100 with a Multireflection Time-of-Flight Mass Spectrograph

Science.gov (United States)

Ito, Y.; Schury, P.; Wada, M.; Arai, F.; Haba, H.; Hirayama, Y.; Ishizawa, S.; Kaji, D.; Kimura, S.; Koura, H.; MacCormick, M.; Miyatake, H.; Moon, J. Y.; Morimoto, K.; Morita, K.; Mukai, M.; Murray, I.; Niwase, T.; Okada, K.; Ozawa, A.; Rosenbusch, M.; Takamine, A.; Tanaka, T.; Watanabe, Y. X.; Wollnik, H.; Yamaki, S.

2018-04-01

The masses of 246Es, 251Fm, and the transfermium nuclei Md-252249 and 254No, produced by hot- and cold-fusion reactions, in the vicinity of the deformed N =152 neutron shell closure, have been directly measured using a multireflection time-of-flight mass spectrograph. The masses of 246Es and 249,250,252Md were measured for the first time. Using the masses of Md,250249 as anchor points for α decay chains, the masses of heavier nuclei, up to 261Bh and 266Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter δ2 n derived from three isotopic masses was updated with the new masses and corroborates the existence of the deformed N =152 neutron shell closure for Md and Lr.

Nuclear structure information studied through Dirac equation with deformed mean fields

International Nuclear Information System (INIS)

Dudek, J.

2000-01-01

Complete text of publication follows. Relativistic mean-field theory provides a formal expression for the Dirac equation for the nucleonic motion in an atomic nucleus. The 'potentials' within such a formalism are given in terms of the meson fields, the latter obtained through a coupled system of equations of the Klein-Grodon type. Usually the whole system is being solved by using a Hartree approximation by employing an iterative selfonsistent algorithms. On a more phenomenological level one can parametrize the potentials that enter into a Dirac equation rather than obtain the selfconsistently; such a simplification was suggested some time ago by the Munich group. We introduce a Woods-Saxon type parametrisation and verify by a non-linear search routine what are the 'best fit potential parameters' that reproduce the single particle excitations in the double-magic spherical nuclei as well as the band-head properties in some hundreds of deformed nuclei. Next, by introducing a low-energy reduction of the Dirac equation, one may obtain in a natural way a Pauli Schrodinger type equation with a position dependent effective mass. The role of the corresponding term in a description of single particle energies of the nucleons is illustrated and the implications for the cranking equation are discussed in some detail. (author)

Isotopic Determination of Nuclear Materials Using Nuclear Fission Track Registration Technique and Thermal Ionization Mass Spectrometric Technique

International Nuclear Information System (INIS)

Jeon, Young Sin; Pyo, Hyeong Yeol; Park, Yong Joon; Song, Kyu Seok; Kim, Won Ho; Jee, Kwang Yong

2007-05-01

It is very important to develope the technology for the determination of isotopic ratios of hot particles( 234 U, 235 U, 236 U etc.) detected from swipe samples of various nuclear facilities. This technology is highly competitive internationally and has to be established independently as long as our government maintains atomic energy and treats nuclear materials. In this text, sample pretreatment procedure, gamma-ray counting, alpha or fission track techniques, isotopic analysis of U and Pu, background problems and detection limits for mass determination, and their application to the real swipe sample were described with detailed procedure. This technology would contribute to the Korean economy's high growth rate as well as to superiority of government's leading research and development programs if successfully established

Nuclear assay of coal. Volume 6. Mass flow devices for coal handling. Final report

International Nuclear Information System (INIS)

Gozani, T.; Elias, E.; Bevan, R.

1980-04-01

The mass of coal entering the boiler per unit time is an essential parameter for determining the total rate of heat input. The mass flow rate of coal on a conveyor belt is generally determined as a product of the instantaneous mass of material on a short section of the belt and the belt velocity. Belt loading could be measured by conventional transducers incorporating mechanical or electromechanical weighers or by gamma-ray attenuation gauge. This report reviews the state of the art in mass flow devices for coal handling. The various methods are compared and commented upon. Special design issues are discussed relative to incorporating a mass flow measuring device in a Continuous On-Line Nuclear Analysis of Coal (CONAC) system

Study of ^{14}C Cluster Decay Half-Lives of Heavy Deformed Nuclei

Science.gov (United States)

Shamami, S. Rahimi; Pahlavani, M. R.

2018-01-01

A theoretical model based on deformed Woods-Saxon, Coulomb and centrifugal terms are constructed to evaluate the half-lives for the cluster radioactivity of various super heavy nuclei. Deformation have been applied on all parts of their potential containing nuclear barrier for cluster decay. Also, both parent and daughter nuclei are considered to be deformed. The calculated results of ^{14}C cluster radioactivity half-lives are compared with available experimental data. A satisfactory agreement between theoretical and measured data is achieved. Also, obtained half-lives for each decay family is agreed with Geiger-Nuttall law.

Nuclear Resonance Fluorescence to Measure Plutonium Mass in Spent Nuclear Fuel

Energy Technology Data Exchange (ETDEWEB)

Ludewigt, Bernhard A; Quiter, Brian J.; Ambers, Scott D.

2011-01-14

The Next Generation Safeguard Initiative (NGSI) of the U.S Department of Energy is supporting a multi-lab/university collaboration to quantify the plutonium (Pu) mass in spent nuclear fuel (SNF) assemblies and to detect the diversion of pins with non-destructive assay (NDA) methods. The following 14 NDA techniques are being studied: Delayed Neutrons, Differential Die-Away, Differential Die-Away Self-Interrogation, Lead Slowing Down Spectrometer, Neutron Multiplicity, Passive Neutron Albedo Reactivity, Total Neutron (Gross Neutron), X-Ray Fluorescence, {sup 252}Cf Interrogation with Prompt Neutron Detection, Delayed Gamma, Nuclear Resonance Fluorescence, Passive Prompt Gamma, Self-integration Neutron Resonance Densitometry, and Neutron Resonance Transmission Analysis. Understanding and maturity of the techniques vary greatly, ranging from decades old, well-understood methods to new approaches. Nuclear Resonance Fluorescence (NRF) is a technique that had not previously been studied for SNF assay or similar applications. Since NRF generates isotope-specific signals, the promise and appeal of the technique lies in its potential to directly measure the amount of a specific isotope in an SNF assay target. The objectives of this study were to design and model suitable NRF measurement methods, to quantify capabilities and corresponding instrumentation requirements, and to evaluate prospects and the potential of NRF for SNF assay. The main challenge of the technique is to achieve the sensitivity and precision, i.e., to accumulate sufficient counting statistics, required for quantifying the mass of Pu isotopes in SNF assemblies. Systematic errors, considered a lesser problem for a direct measurement and only briefly discussed in this report, need to be evaluated for specific instrument designs in the future. Also, since the technical capability of using NRF to measure Pu in SNF has not been established, this report does not directly address issues such as cost, size

Collective nuclear dynamics. Abstracts

International Nuclear Information System (INIS)

Abrosimov, V.I.; Kolomietz, V.M.

1994-01-01

The fourth International school on nuclear physics was help on 29 Aug - 7 Sep, 1994 in Ukraine. The specialists discussed following subjects: liquid drop and the shell correction method; nuclear deformation energy and fission; nuclear structure at high spins, superdeformed states, structure of excited and exotic nuclei; nuclear fluid dynamics and large scale collective motion; order and chaos as they relate to the collective motion; quantum and interference phenomena in nuclear collisions; quasi-fission and multinucleon fragmentation effects; shell effects in non-nuclear systems; new nuclear facilities

Collective nuclear dynamics. Proceedings

International Nuclear Information System (INIS)

Ivanyuk, F.A.

1994-01-01

The Fourth International school on nuclear physics was help on 29 Aug - 7 Sep, 1994 in Ukraine. The specialists discussed following subjects:liquid drop and the shell correction method; nuclear deformation energy and fission; nuclear structure at high spins, superdeformed states, structure of excited and exotic nuclei; nuclear fluid dynamics and large scale collective motion; order and chaos as they relate to the collective motion; quantum and interference phenomena in nuclear collisions; quasi-fission and multinucleon fragmentation effects; shell effects in non-nuclear systems; new nuclear facilities

Collective nuclear dynamics. Proceedings.

Energy Technology Data Exchange (ETDEWEB)

Ivanyuk, F A [eds.

1994-12-31

The Fourth International school on nuclear physics was help on 29 Aug - 7 Sep, 1994 in Ukraine. The specialists discussed following subjects:liquid drop and the shell correction method; nuclear deformation energy and fission; nuclear structure at high spins, superdeformed states, structure of excited and exotic nuclei; nuclear fluid dynamics and large scale collective motion; order and chaos as they relate to the collective motion; quantum and interference phenomena in nuclear collisions; quasi-fission and multinucleon fragmentation effects; shell effects in non-nuclear systems; new nuclear facilities.

Storage ion trap of an 'In-Flight Capture' type for precise mass measurement of radioactive nuclear reaction products and fission fragments

International Nuclear Information System (INIS)

Tarantin, N.I.

2001-01-01

Data on nuclear masses provide a basis for creating and testing various nuclear models. A tandem system of FLNR comprised of the U-400M cyclotron, the COMBAS magnetic separator and the mass-spectrometric ion trap of an 'in-flight capture' type is considered as a possible complex for producing of the short-lived nuclei in fragmentation reactions by heavy ions and for precise mass measurement of these nuclei. The plan of scientific and technical FLNR research includes a project DRIBs for producing beams of accelerated radioactive nuclear reaction products and photofission fragments. This project proposes also precise mass measurements of the fission fragment with the help of the ion trap. The in-flight entrance of the ions and their capture in the mass-spectrometric ion trap using the monochromatizing degrader, the static electric and magnetic fields and a new invention, a magnetic unidirectional transporting ventil, is considered

Development of deformation in the island of inversion at N=40

International Nuclear Information System (INIS)

Lenzi, Silvia Monica

2012-01-01

Full text: Far from the valley of beta stability, the nuclear shell structure undergoes important and substantial modifications. In medium-light nuclei, interesting changes have been observed such as the appearance of new magic numbers, and the development of new regions of deformation around nucleon numbers that are magic near stability. The observed changes help to shed light on specific terms of the effective nucleon-nucleon interaction and to improve our knowledge of the nuclear structure evolution towards the drip lines. In particular, it has been shown that the monopole part of the tensor force of the proton-neutron interaction gives the main contribution to the shell evolution. The possibility of having a good theoretical description of these phenomena is essential to allow a deep insight into the nuclear effective interaction, to interpret the structure of nuclei far from stability, to predict the position of the drip-lines and to understand the nucleosynthesis pathways. In the last few years, particular effort has been put on studying light and medium-mass neutron-rich nuclei where these effects manifest more dramatically. Recent results on the spectroscopy of nuclei south of 68 Ni, where rapid shape changes and shape coexistence have been observed, will be presented together with the large scale shell model calculations that are able to describe and interpret the data with very good accuracy. (author)

Coupling of mass and charge distributions for low excited nuclear fission

International Nuclear Information System (INIS)

Salamatin, V.S.; )

2000-01-01

The simple model for calculation of charge distributions of fission fragments for low exited nuclear fission from experimental mass distributions is offered. The model contains two parameters, determining amplitude of even-odd effect of charge distributions and its dependence on excitation energy. Results for reactions 233 U(n th ,f), 235 U(n th ,f), 229 Th(n th ,f), 249 Cf(n th ,f) are spent [ru

Volumes, Masses, and Surface Areas for Shippingport LWBR Spent Nuclear Fuel in a DOE SNF Canister

International Nuclear Information System (INIS)

J.W. Davis

1999-01-01

The purpose of this calculation is to estimate volumes, masses, and surface areas associated with (a) an empty Department of Energy (DOE) 18-inch diameter, 15-ft long spent nuclear fuel (SNF) canister, (b) an empty DOE 24-inch diameter, 15-ft long SNF canister, (c) Shippingport Light Water Breeder Reactor (LWBR) SNF, and (d) the internal basket structure for the 18-in. canister that has been designed specifically to accommodate Seed fuel from the Shippingport LWBR. Estimates of volumes, masses, and surface areas are needed as input to structural, thermal, geochemical, nuclear criticality, and radiation shielding calculations to ensure the viability of the proposed disposal configuration

Woods-Saxon potential parametrization at large deformations for odd-plutonium nuclei

International Nuclear Information System (INIS)

Garcia, F.; Yoneama, M.L.; Arruda Neto, J.D.T.; Mesa, J.; Bringas, F.; Dias, J.F.; Likhachev, V.P.

1997-01-01

The structure of the the single-particle levels in the secondary minima of 237,239,241 Pu fissioning nuclei is analysed with the help of an axially-deformed Woods-Saxon potential. The nuclear shape was parametrized in terms of the Cassinian ovaloids. The parametrization of the spin-orbit part of the potential in the region corresponding to large deformations (second minimum), which depends only on the nuclear surface area, B s , was obtained. With this relation we were able to reproduce successfully the spin (parity) and the energies of the rotational band built on the 8μs isomeric rate in 239 Pu and also to make a spin assignment for both isomer states in 237 Pu and 241 Pu. (author)

Deformation of cylindrical vessel and the effect of barrel on deformation under inpulsive pressure of high explosive

International Nuclear Information System (INIS)

Iikura, Shoichi; Yashizawa, Hiroyasu; Sasanuma, Katsumi.

1982-01-01

According to the research performed so far, the result that the amount of deformation due to impulsive pressure was able to be evaluated by the impulse of impulsive pressure waves has been obtained. The analysis treating impulsive pressure waves as plane waves has been made frequently, but the analysis in which impulsive pressure waves must be treated as spherical waves, or the analysis of a vessel with a barrel (internal cylinder) is complex and difficult. In this report, the results of element test, which was carried out in the Oita Works, Asahi Chemical Industry Co., Ltd., in 1973 by the Power Reactor and Nuclear Fuel Development Corp. as the impact resistance test for fast breeder reactors, are rearranged and investigated. The specimens were the cylindrical vessels with upper and lower flanges, and 10 vessels and 9 kinds of barrels were made. Water was used as the pressure medium. The residual deformation and dynamic strain of the vessels and the wave form of pressure waves were measured. The deformation of cylindrical vessels subjected to the impulsive pressure from a point pressure source was able to be evaluated by the impulse distribution in normal direction. The maximum amount of deformation depended on the total plate thickness of barrels. (Kako, I.)

An electromechanical based deformable model for soft tissue simulation.

Science.gov (United States)

Zhong, Yongmin; Shirinzadeh, Bijan; Smith, Julian; Gu, Chengfan

2009-11-01

Soft tissue deformation is of great importance to surgery simulation. Although a significant amount of research efforts have been dedicated to simulating the behaviours of soft tissues, modelling of soft tissue deformation is still a challenging problem. This paper presents a new deformable model for simulation of soft tissue deformation from the electromechanical viewpoint of soft tissues. Soft tissue deformation is formulated as a reaction-diffusion process coupled with a mechanical load. The mechanical load applied to a soft tissue to cause a deformation is incorporated into the reaction-diffusion system, and consequently distributed among mass points of the soft tissue. Reaction-diffusion of mechanical load and non-rigid mechanics of motion are combined to govern the simulation dynamics of soft tissue deformation. An improved reaction-diffusion model is developed to describe the distribution of the mechanical load in soft tissues. A three-layer artificial cellular neural network is constructed to solve the reaction-diffusion model for real-time simulation of soft tissue deformation. A gradient based method is established to derive internal forces from the distribution of the mechanical load. Integration with a haptic device has also been achieved to simulate soft tissue deformation with haptic feedback. The proposed methodology does not only predict the typical behaviours of living tissues, but it also accepts both local and large-range deformations. It also accommodates isotropic, anisotropic and inhomogeneous deformations by simple modification of diffusion coefficients.

Strategy of the Romanian Public Information Policy in the Nuclear Field

International Nuclear Information System (INIS)

Stiopol, Mihaela; Manole, Felicia; Paunescu, Aurelia; Petran, Catalina; Chiper, Livia

1998-01-01

In the framework the Romania's nuclear power program the first Romanian NPP has been built at Cernavoda and the Unit 1, based on a CANDU type reactor, was commissioned on December 2, 1996. The start of the entire nuclear program in Romania, some 20 years ago, was a high level government decision with no public hearing or acceptance, either, but obviously based on economic and political considerations. After 1990 favorable and unfavorable articles in the mass media, most of them lacking of technical background, had led to distorted and false perception of information. The strategy of public information policy in the nuclear field should be guided by the following facts: a) the public perception of the nuclear energy problems in general, and of nuclear power, in particular, is deeply deformed by the ignorance in the domain; b) first of all the public fears for its health menaced by radiation and radioactive wastes; c) the public due not know the actual dimension and potential of the Romanian industry in this field, the qualitative progress brought about by the implementation of the nuclear program in the Romania's economy; d) the public vulnerability when exposed to the mass media which, owing to its rush towards sensational or due to the lack of knowledge in the field, rather often have launched simple, unfounded speculations. The paper presents the basic principles which are underlying the public information program and lists suggestions for the future activity concerning: A - the educational programs addressed to young people; B - development of computer-assisted educational programs; C - the relationship with mass media; D - accomplishing an adequate information through publications; E - organizing and/or participating in exhibitions displaying nuclear power development; F - advertising actions related to promotion of Unit 2 - 5 project at Cernavoda NPP

High-accuracy mass determination of unstable nuclei with a Penning trap mass spectrometer

CERN Multimedia

2002-01-01

The mass of a nucleus is its most fundamental property. A systematic study of nuclear masses as a function of neutron and proton number allows the observation of collective and single-particle effects in nuclear structure. Accurate mass data are the most basic test of nuclear models and are essential for their improvement. This is especially important for the astrophysical study of nuclear synthesis. In order to achieve the required high accuracy, the mass of ions captured in a Penning trap is determined via their cyclotron frequency $ \

Numerical simulation of the time-dependent deformation behaviour of clay-stone rock mass at the Tournemire site with 2D and 3D models

International Nuclear Information System (INIS)

Rutenberg, M.; Lux, K.H.

2010-01-01

Document available in extended abstract form only. Modern repository research foregrounds physico-chemical processes (mechanical, hydraulic, thermal, chemical) and their interactions taking place in the near field and the far field of the geological system being explored. With regard to load bearing behaviour and preservation of barrier integrity, and with the general objective of complete confinement of the waste in the isolating rock zone, the focus is especially on geomechanical processes induced by excavation - including the influences on and by hydraulic, thermal, and chemical processes - as well as on thermal processes induced by heat generation of the deposited radioactive waste and their effects on mechanical and hydraulic processes. In order to improve assessments of the mechanical stability and, in case of a water saturated rock formation, of the hydraulic effects on the host rock of the repository, suitable physical models for numerical simulations of rock and rock mass behaviour have to be found and to be validated. Because of their radionuclide retention capacity, their low water permeability, and their resistance to water, clay-stone rock masses form a reasonable alternative to e.g. salt rock masses as a host rock for deep geological repositories. In past decades, various working groups at an international level have elaborated a broad experimental and theoretical understanding of the geomechanical and geo-hydraulic behaviour of clay-stones and applied this know-how to geologic repository components, e.g. in the context of engineering studies, or in the back-analysis of field tests. In this context, measurement results revealed a continuing convergence of drift walls lasting for a few years after completion of excavation. Possible reasons for this time-dependent deformation behaviour of the clay-stone rock mass might be: - viscous properties of the material from a phenomenological point of view, meaning a constant stress state leading to increasing

Research on geometrical model and mechanism for metal deformation based on plastic flow

International Nuclear Information System (INIS)

An, H P; Li, X; Rui, Z Y

2015-01-01

Starting with general conditions of metal plastic deformation, it analyses the relation between the percentage spread and geometric parameters of a forming body with typical machining process are studied. A geometrical model of deforming metal is set up according to the characteristic of a flowing metal particle. Starting from experimental results, the effect of technological parameters and friction between workpiece and dies on plastic deformation of a material were studied and a slippage deformation model of mass points within the material was proposed. Finally, the computing methods for strain and deformation energy and temperature rise are derived from homogeneous deformation. The results can be used to select technical parameters and compute physical quantities such as strain, deformation energy, and temperature rise. (paper)

Relativistic extension of the complex scaled Green's function method for resonances in deformed nuclei

Energy Technology Data Exchange (ETDEWEB)

Shi, Min [Anhui University, School of Physics and Materials Science, Hefei (China); RIKEN Nishina Center, Wako (Japan); Shi, Xin-Xing; Guo, Jian-You [Anhui University, School of Physics and Materials Science, Hefei (China); Niu, Zhong-Ming [Anhui University, School of Physics and Materials Science, Hefei (China); Interdisciplinary Theoretical Science Research Group, RIKEN, Wako (Japan); Sun, Ting-Ting [Zhengzhou University, School of Physics and Engineering, Zhengzhou (China)

2017-03-15

We have extended the complex scaled Green's function method to the relativistic framework describing deformed nuclei with the theoretical formalism presented in detail. We have checked the applicability and validity of the present formalism for exploration of the resonances in deformed nuclei. Furthermore, we have studied the dependences of resonances on nuclear deformations and the shape of potential, which are helpful to recognize the evolution of resonant levels from stable nuclei to exotic nuclei with axially quadruple deformations. (orig.)

Nuclear diffuseness as a degree of freedom

Science.gov (United States)

Myers, W. D.; ŚwiaŢecki, W. J.

1998-12-01

The response of the nuclear energy to changes in neutron and proton surface diffusenesses is investigated using the Thomas-Fermi model. Algebraic expressions are provided for the energy cost of changing the two diffusenesses away from their equilibrium values. This will make it possible to generalize the macroscopic-microscopic calculations of nuclear masses and deformation energies by the inclusion of the neutron and proton diffusenesses as degrees of freedom (to be varied along with the shape degrees of freedom). One result, which is suggested by the relatively low cost in macroscopic energy of increasing the diffuseness of a heavy nucleus by 10% (about 4 MeV), is that superheavy nuclei near Z=126, N=184 may have a fair chance of becoming stabilized by shell effects. An appendix introduces an improved measure of surface diffuseness, with certain advantages over the conventional Süssmann width b.

Nuclear diffuseness as a degree of freedom

International Nuclear Information System (INIS)

Myers, W.D.; Swiatecki, W.J.

1998-01-01

The response of the nuclear energy to changes in neutron and proton surface diffusenesses is investigated using the Thomas-Fermi model. Algebraic expressions are provided for the energy cost of changing the two diffusenesses away from their equilibrium values. This will make it possible to generalize the macroscopic-microscopic calculations of nuclear masses and deformation energies by the inclusion of the neutron and proton diffusenesses as degrees of freedom (to be varied along with the shape degrees of freedom). One result, which is suggested by the relatively low cost in macroscopic energy of increasing the diffuseness of a heavy nucleus by 10% (about 4 MeV), is that superheavy nuclei near Z=126, N=184 may have a fair chance of becoming stabilized by shell effects. An appendix introduces an improved measure of surface diffuseness, with certain advantages over the conventional Suessmann width b. copyright 1998 The American Physical Society

Classical studies of the ellipsoidal shapes for dynamical deformation theories of the nucleus

International Nuclear Information System (INIS)

Remaud, B.

1978-01-01

The shape-dependent functions of the Liquid Drop and the Droplet Models are analytically calculated for an ellipsoid. Using the ellipsoidal symmetries, these functions (including the curvature function) are written in terms of three basic expressions. The nuclear deformation energy can be calculated in a simple way for axially symmetric and asymmetric ellipsoidal nuclei whatever the magnitude of the deformation is

Deformation effects in the 20Ne+12C reaction

International Nuclear Information System (INIS)

Dey, A.; Bhattacharya, C.; Banerjee, K.; Kundu, S.; Mukhopadhyay, S.; Gupta, D.; Saha, R.; Bhattacharya, S.

2004-01-01

The present work has been performed with the aim to investigate the possible occurrence of highly deformed configurations of the 32 S di-nuclear systems which may be formed in the 20 Ne+ 12 C reaction by studying the properties of emitted light charged particles

Deformed N = 8 supergravity from IIA strings and its Chern-Simons duals

Energy Technology Data Exchange (ETDEWEB)

Guarino, Adolfo [Nikhef Theory Group, Amsterdam (Netherlands); Jafferis, Daniel L. [Center for the Fundamental Laws of Nature, Harvard University, Cambridge, MA (United States); Varela, Oscar [Center for the Fundamental Laws of Nature, Harvard University, Cambridge, MA (United States); Centre de Physique Theorique, Ecole Polytechnique, CNRS UMR 7644, Palaiseau (France)

2016-04-15

Do electric/magnetic deformations of N = 8 supergravity enjoy a string/M-theory origin, or are they just a fourdimensional artefact? We address this question for the gauging of a group closely related to SO(8): its contraction ISO(7). We argue that the deformed ISO(7) supergravity arises from consistent truncation of massive IIA supergravity on S{sup 6}, and its electric/magnetic deformation parameter descends directly from the Romans mass. The critical points of the supergravity uplift to AdS{sub 4} massive type IIA vacua and the corresponding CFT{sub 3} duals are identified as super-Chern-Simons-matter theories with gauge group SU(N) and level k given also by the Romans mass. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solutions

International Nuclear Information System (INIS)

Anon.

1981-01-01

The standard covers analytical procedures to determine compliance of nuclear-grade uranyl nitrate solution to specifications. The following methods are described in detail: uranium by ferrous sulfate reduction-potassium dichromate titrimetry and by ignition gravimetry; specific gravity by pycnometry; free acid by oxalate complexation; thorium by the Arsenazo(III) (photometric) method; chromium by the diphenylcarbazide (photometric) method; molybdenum by the thiocyanate (photometric) method; halogens separation by steam distillation; fluorine by specific ion electrode; halogen distillate analysis: chloride, bromide and iodide by amperometric microtitrimetry; bromine by the fluorescein (photometric) method; sulfate sulfur by (photometric) turbidimetry; phosphorus by the molybdenum blue (photometric) method; silicon by the molybdenum blue (photometric) method; carbon by persulfate oxidation-acid titrimetry; nonvolatile impurities by spectrography; volatile impurities by rotating-disk spark spectrography; boron by emission spectrography; impurity elements by spark source mass spectrography; isotopic composition by multiple filament surface-ionization mass spectrometry; uranium-232 by alpha spectrometry; total alpha activity by direct alpha counting; fission product activity by beta and gamma counting; entrained organic matter by infrared spectrophotometry

Radiocarbon mass balance for a Magnox nuclear power station

International Nuclear Information System (INIS)

Metcalfe, M.P.; Mills, R.W.

2015-01-01

Highlights: • First comprehensive assessment of C-14 arisings in a Magnox nuclear power station. • C-14 production in graphite and coolant gas quantified by activation modelling. • Principal C-14 production pathway is via C-13 with a small contribution from N-14. • C-14 mass balance model provides a basis for analyses on other reactors. - Abstract: Nuclear power generation in the United Kingdom is based principally on graphite-moderated gas-cooled reactors. The mass of irradiated graphite associated with these reactors, including material from associated experimental, prototype and plutonium production reactors, exceeds 96,000 tonnes. One of the principal long-lived radionuclides produced during graphite irradiation is radiocarbon (C-14). Its potential as a hazard must be taken into account in decommissioning and graphite waste management strategies. While C-14 production processes are well-understood, radionuclide distributions and concentrations need to be characterised. A common misconception is that generic statements can be made about C-14 precursors and their location. In fact, the composition of the original manufactured material, the chemical environment of the graphite during service and its irradiation history will all influence C-14 levels. The analysis presented here provides the first assessment of the principal C-14 activation pathways for a UK Magnox reactor. Activation modelling has been used to predict C-14 production rates in both the graphite core and the carbon dioxide coolant over a selected period of operation and the results compared with monitored site C-14 discharges. Principal activation routes have been identified, which should inform future graphite waste management strategies relating to radiocarbon

Finite element analysis of large elasto-plastic deformation for sealing ring in nuclear pressure vessel

International Nuclear Information System (INIS)

Xiao Xuejian; Chen Ruxin

1995-02-01

Based on the R. Hills incremental virtual power principle and the elasto-plastic constitution equation for large deformation and by considering physical nonlinear, geometric nonlinear and thermal effects, a plane and axisymmetric finite element equation for thermal large elasto-plastic deformation has been established in the Euler description. The corresponding analysis program ATLEPD has been also complied for thermal large elasto-plastic deformation process of O-ring in RPV. The variations of stress, strain, contact specific pressure, mesh deformation and the aspects of spring back in upsetting and spring back process have been also investigated. Numerical results are fairly consistent with experimental ones. (5 figs., 4 tabs.)

Isotopic yield measurement in the heavy mass region for 239Pu thermal neutron induced fission

International Nuclear Information System (INIS)

Bail, A.; Serot, O.; Mathieu, L.; Litaize, O.; Materna, T.; Koester, U.; Faust, H.; Letourneau, A.; Panebianco, S.

2011-01-01

Despite the huge number of fission yield data available in the different evaluated nuclear data libraries, such as JEFF-3.1.1, ENDF/B-VII.0, and JENDL-4.0, more accurate data are still needed both for nuclear energy applications and for our understanding of the fission process itself. It is within the framework of this that measurements on the recoil mass spectrometer Lohengrin (at the Institut Laue-Langevin, Grenoble, France) was undertaken, to determine isotopic yields for the heavy fission products from the 239 Pu(n th ,f) reaction. In order to do this, a new experimental method based on γ-ray spectrometry was developed and validated by comparing our results with those performed in the light mass region with completely different setups. Hence, about 65 fission product yields were measured with an uncertainty that has been reduced on average by a factor of 2 compared to that previously available in the nuclear data libraries. In addition, for some fission products, a strongly deformed ionic charge distribution compared to a normal Gaussian shape was found, which was interpreted as being caused by the presence of a nanosecond isomeric state. Finally, a nuclear charge polarization has been observed in agreement, with the one described on other close fissioning systems.

Isotopic yield measurement in the heavy mass region for 239Pu thermal neutron induced fission

Science.gov (United States)

Bail, A.; Serot, O.; Mathieu, L.; Litaize, O.; Materna, T.; Köster, U.; Faust, H.; Letourneau, A.; Panebianco, S.

2011-09-01

Despite the huge number of fission yield data available in the different evaluated nuclear data libraries, such as JEFF-3.1.1, ENDF/B-VII.0, and JENDL-4.0, more accurate data are still needed both for nuclear energy applications and for our understanding of the fission process itself. It is within the framework of this that measurements on the recoil mass spectrometer Lohengrin (at the Institut Laue-Langevin, Grenoble, France) was undertaken, to determine isotopic yields for the heavy fission products from the 239Pu(nth,f) reaction. In order to do this, a new experimental method based on γ-ray spectrometry was developed and validated by comparing our results with those performed in the light mass region with completely different setups. Hence, about 65 fission product yields were measured with an uncertainty that has been reduced on average by a factor of 2 compared to that previously available in the nuclear data libraries. In addition, for some fission products, a strongly deformed ionic charge distribution compared to a normal Gaussian shape was found, which was interpreted as being caused by the presence of a nanosecond isomeric state. Finally, a nuclear charge polarization has been observed in agreement, with the one described on other close fissioning systems.

Saturation of Deformation and Identical Bands in Very-Neutron Rich Sr Isotopes

CERN Multimedia

2002-01-01

The present proposal aims at establishing nuclear properties in an isotopic chain showing unique features. These features include the saturation of ground state deformation at its onset and the existence of ground state identical bands in neighbouring nuclei with the same deformation. The measurements should help to elucidate the role played by the proton-neutron residual interaction between orbitals with large spatial overlap, i.e. $\\pi g _{9/2} \

Experience with nuclear fuel utilization in Bulgaria

Energy Technology Data Exchange (ETDEWEB)

Harizanov, Y [Committee on the Use of Atomic Energy for Peaceful Purposes, Sofia (Bulgaria)

1997-12-01

The presentation on experience with nuclear fuel utilization in Bulgaria briefly reviews the situation with nuclear energy in Bulgaria and then discusses nuclear fuel performance (amount of fuel loaded, type of fuel, burnup, fuel failures, assemblies deformation). 2 tabs.

Double Beta Decay and Neutrino Masses Accuracy of the Nuclear Matrix Elements

International Nuclear Information System (INIS)

Faessler, Amand

2005-01-01

The neutrinoless double beta decay is forbidden in the standard model of the electroweak and strong interaction but allowed in most Grand Unified Theories (GUT's). Only if the neutrino is a Majorana particle (identical with its antiparticle) and if it has a mass, the neutrinoless double beta decay is allowed. Apart of one claim that the neutrinoless double beta decay in 76 Ge is measured, one has only upper limits for this transition probability. But even the upper limits allow to give upper limits for the electron Majorana neutrino mass and upper limits for parameters of GUT's and the minimal R-parity violating supersymmetric model. One further can give lower limits for the vector boson mediating mainly the right-handed weak interaction and the heavy mainly right-handed Majorana neutrino in left-right symmetric GUT's. For that one has to assume that the specific mechanism is the leading one for the neutrinoless double beta decay and one has to be able to calculate reliably the corresponding nuclear matrix elements. In the present contribution, one discusses the accuracy of the present status of calculating the nuclear matrix elements and the corresponding limits of GUT's and supersymmetric parameters

A review of experimental evidence for octupole deformation

International Nuclear Information System (INIS)

Zylicz, J.

1986-08-01

Experimental evidence for octupole correlations, which lead to octupole instability and octupole deformation of some nuclei, is illustrated through typical examples. Data are considered for both the 220< A<230 region and for a few medium mass nuclei. (orig.)

NONINVASIVE DETERMINATION OF KNEE CARTILAGE DEFORMATION DURING JUMPING

Directory of Open Access Journals (Sweden)

Djordje Kosanic

2009-12-01

Full Text Available The purpose of this investigation was to use a combination of image processing, force measurements and finite element modeling to calculate deformation of the knee cartilage during jumping. Professional athletes performed jumps analyzed using a force plate and high-speed video camera system. Image processing was performed on each frame of video using a color recognition algorithm. A simplified mass-spring-damper model was utilized for determination of global force and moment on the knee. Custom software for fitting the coupling characteristics was created. Simulated results were used as input data for the finite element calculation of cartilage deformation in the athlete's knee. Computer simulation data was compared with the average experimental ground reaction forces. The results show the three-dimensional mechanical deformation distribution inside the cartilage volume. A combination of the image recognition technology, force plate measurements and the finite element cartilage deformation in the knee may be used in the future as an effective noninvasive tool for prediction of injury during jumping

The limits of the nuclear chart set by fission and alpha decay

Directory of Open Access Journals (Sweden)

Möller Peter

2016-01-01

Full Text Available I will review how our picture of heavy-element nuclear structure has evolved through remarkably simple ideas and related models. It is well known that the Bethe-Weizsäcker semi-empirical mass model had an important role in unraveling radioactive decay and element transmutation in the heavy-element region in the 1930s. A remarkable aspect is that this model could immediately after the discovery of fission be generalized to explain this phenomenon through the consideration of deformation of a charged liquid drop. Bethe and Bacher already raised the possibility that shell structure (by them calculated in terms of a single-particle oscillator potential could give rise to noticeable deviations between results of the macroscopic mass model and experiment but limited data prevented firm conclusions. In the 1950s the single-particle models took a realistic form and also included deformation. The possibility of the existence of a relatively stable “island” of superheavy elements was raised already then. But it was not until the work by Strutinsky in the mid 1960s that a quantitative model for the nuclear potential-energy emerged in the form of the macroscopic-microscopic model. Although new elements have been discovered at an almost steady pace since 1940, theory indicates that we are close to the end of this era: repulsive Coulomb effects will set the limit of observable elements to near Z = 120.

A novel deformation mechanism for superplastic deformation

Energy Technology Data Exchange (ETDEWEB)

Muto, H.; Sakai, M. (Toyohashi Univ. of Technology (Japan). Dept. of Materials Science)

1999-01-01

Uniaxial compressive creep tests with strain value up to -0.1 for a [beta]-spodumene glass ceramic are conducted at 1060 C. From the observation of microstructural changes between before and after the creep deformations, it is shown that the grain-boundary sliding takes place via cooperative movement of groups of grains rather than individual grains under the large-scale-deformation. The deformation process and the surface technique used in this work are not only applicable to explain the deformation and flow of two-phase ceramics but also the superplastic deformation. (orig.) 12 refs.

Analysis of interactions of mechanical deformations and mass transfer on heat transfer from an underground nuclear-waste repository. Final report

International Nuclear Information System (INIS)

Bloom, S.G.; Hulbert, L.E.

1979-10-01

A review of existing models identified several effects that may need consideration in further model development. Most of these effects involved coupling equations through variable property values rather than through omission of any significant mechanism. However, it was also shown that more than one mechanism may adequately simulate a given set of experimental data and additional experimental data are needed to establish which (if any) of the possible mechanisms would actually control conditions in a nuclear waste repository. In particular, it is believed that mathematical modeling of major thermomechanical effects can be accomplished with finite element analysis computer programs, provided that adequate thermomechanical property data of salt and overburden are attained. An attempt was made to develop a general set of differential equations for simulating momentum, mass, and energy flows in geologic formations in order to illustrate the possible mechanisms and point out those included and not included in existing models. Most of the mechanisms are included in some manner in existing models although some approximations may not be adequate. More experimental data are required to assess the importance of most omitted mechanisms. Analysis of some data on brine migration in salt indicated that two mechanisms, acting simultaneously, could adequately explain the flow. These are Darcy flow and a combination of ordinary and thermal diffusion enhanced by temperature-dependent solubility. Equations based on this simultaneous action correlated the data very well and indicated the possible need to include both (and, maybe other) mechanisms in future models. A program is recommended for further study of brine mobility. An expected result of this program includes recommendations for further experimental work

Analysis of interactions of mechanical deformations and mass transfer on heat transfer from an underground nuclear-waste repository. Final report

Energy Technology Data Exchange (ETDEWEB)

Bloom, S.G.; Hulbert, L.E.

1979-10-01

A review of existing models identified several effects that may need consideration in further model development. Most of these effects involved coupling equations through variable property values rather than through omission of any significant mechanism. However, it was also shown that more than one mechanism may adequately simulate a given set of experimental data and additional experimental data are needed to establish which (if any) of the possible mechanisms would actually control conditions in a nuclear waste repository. In particular, it is believed that mathematical modeling of major thermomechanical effects can be accomplished with finite element analysis computer programs, provided that adequate thermomechanical property data of salt and overburden are attained. An attempt was made to develop a general set of differential equations for simulating momentum, mass, and energy flows in geologic formations in order to illustrate the possible mechanisms and point out those included and not included in existing models. Most of the mechanisms are included in some manner in existing models although some approximations may not be adequate. More experimental data are required to assess the importance of most omitted mechanisms. Analysis of some data on brine migration in salt indicated that two mechanisms, acting simultaneously, could adequately explain the flow. These are Darcy flow and a combination of ordinary and thermal diffusion enhanced by temperature-dependent solubility. Equations based on this simultaneous action correlated the data very well and indicated the possible need to include both (and, maybe other) mechanisms in future models. A program is recommended for further study of brine mobility. An expected result of this program includes recommendations for further experimental work.

The long-term strength and deformation properties of crystalline rock in a high level nuclear waste repository

International Nuclear Information System (INIS)

Tuokko, T.

1990-12-01

The time-dependent phenomena which can affect the strength and deformation properties of hard crystal line rock are clarified. Suitable measuring methods for field conditions are also summarized. The significance of time is evaluated around a shaft in a high level nuclear waste repository. According to the investigation it is generally held that creep and cyclic fatigue are the most important phenomena. They arise from subcritical crack growth which is most affected by stress intensity, chemical environment, temperature, and microstructure. There are many theoretical models, which can be used to analyse creep and cyclic fatigue, but they are defective in describing the triaxial stress condition and strength criteria. Additionally, the required parameters are often too difficult to determine with adequate accuracy. The joint creep rate depends on the affecting stress regime, on the water conditions, and on the properties of filling material. The acoustic emission method is suited to observe long-term microcrack development in field conditions. The computer program developed by Atomic Energy of Canada Limited (AECL) is used to evaluate the time-dependent de-formation around a main shaft. According to the model the enlargement of the shaft radius by 30 cm takes millions of years. The possible reduction of shaft radius by 3 mm will happen during 200 years. The model is very sensitive to changes in stress state, in the uniaxial compressive strength, and in the stress corrosion index

Simple, empirical approach to predict neutron capture cross sections from nuclear masses

Science.gov (United States)

Couture, A.; Casten, R. F.; Cakirli, R. B.

2017-12-01

Background: Neutron capture cross sections are essential to understanding the astrophysical s and r processes, the modeling of nuclear reactor design and performance, and for a wide variety of nuclear forensics applications. Often, cross sections are needed for nuclei where experimental measurements are difficult. Enormous effort, over many decades, has gone into attempting to develop sophisticated statistical reaction models to predict these cross sections. Such work has met with some success but is often unable to reproduce measured cross sections to better than 40 % , and has limited predictive power, with predictions from different models rapidly differing by an order of magnitude a few nucleons from the last measurement. Purpose: To develop a new approach to predicting neutron capture cross sections over broad ranges of nuclei that accounts for their values where known and which has reliable predictive power with small uncertainties for many nuclei where they are unknown. Methods: Experimental neutron capture cross sections were compared to empirical mass observables in regions of similar structure. Results: We present an extremely simple method, based solely on empirical mass observables, that correlates neutron capture cross sections in the critical energy range from a few keV to a couple hundred keV. We show that regional cross sections are compactly correlated in medium and heavy mass nuclei with the two-neutron separation energy. These correlations are easily amenable to predict unknown cross sections, often converting the usual extrapolations to more reliable interpolations. It almost always reproduces existing data to within 25 % and estimated uncertainties are below about 40 % up to 10 nucleons beyond known data. Conclusions: Neutron capture cross sections display a surprisingly strong connection to the two-neutron separation energy, a nuclear structure property. The simple, empirical correlations uncovered provide model-independent predictions of

Multi-quasiparticle high-K isomeric states in deformed nuclei

Directory of Open Access Journals (Sweden)

Xu F. R.

2016-01-01

Full Text Available In the past years, we have made many theoretical investigations on multi-quasiparticle high-K isomeric states. A deformation-pairing-configuration self-consistent calculation has been developed by calculating a configuration-constrained multi-quasiparticle potential energy surface (PES. The specific single-particle orbits that define the high-K configuration are identified and tracked (adiabatically blocked by calculating the average Nilsson numbers. The deformed Woods-Saxon potential was taken to give single-particle orbits. The configuration-constrained PES takes into account the shape polarization effect. Such calculations give good results on excitation energies, deformations and other structure information about multi-quasiparticle high-K isomeric states. Many different mass regions have been investigated.

Research in theoretical nuclear physics, Nuclear Theory Group. Progress report

International Nuclear Information System (INIS)

Brown, G.E.; Jackson, A.D.; Kuo, T.T.S.

1984-01-01

Primary emphasis is placed on understanding the nature of nucleon-nucleon and meson-nucleon interactions and on determining the consequences of such microscopic interactions in nuclear systems. We have constructed models of baryons which smoothly interpolate between currently popular bag and Skyrme models of hadrons and provide a vehicle for introducing the notions of quantum chromodynamics to low energy nuclear physics without violating the constraints of chiral invariance. Such models have been used to study the nucleon-nucleon interaction, the spectrum of baryons, and the important question of the radius of the quark bag. We have used many-body techniques to consider a variety of problems in finite nuclei and infinite many-body systems. New light has been shed on the nuclear coexistence of spherical and deformed states in the A = 18 region as well as the role of genuine three-body forces in this region. Phenomenological studies of infinite systems have led to a number of predictions particularly regarding the spin-polarized quantum liquids of current experimental interest. Microscopic many-body theories, based on the parquet diagrams, have been improved to a fully quantitative level for the ground state properties of infinite many-body systems. Finite temperature theories of nuclear matter, important in the study of heavy ion reactions, have been constructed. An expanded program in heavy ion theory has led to major advances in the multi-dimensional barrier penetration problem. Activities in nuclear astrophysics have provided a far more reliable description of the role of electron capture processes in stellar collapse. As a consequence, we have been able to perform legitimate calculations of the unshocked mass in Type II supernovae

Deformation of the Galactic Centre stellar cusp due to the gravity of a growing gas disc

Science.gov (United States)

Kaur, Karamveer; Sridhar, S.

2018-06-01

The nuclear star cluster surrounding the massive black hole at the Galactic Centre consists of young and old stars, with most of the stellar mass in an extended, cuspy distribution of old stars. The compact cluster of young stars was probably born in situ in a massive accretion disc around the black hole. We investigate the effect of the growing gravity of the disc on the orbits of the old stars, using an integrable model of the deformation of a spherical star cluster with anisotropic velocity dispersions. A formula for the perturbed phase-space distribution function is derived using linear theory, and new density and surface density profiles are computed. The cusp undergoes a spheroidal deformation with the flattening increasing strongly at smaller distances from the black hole; the intrinsic axis ratio ˜0.8 at ˜0.15 pc. Stellar orbits are deformed such that they spend more time near the disc plane and sample the dense inner parts of the disc; this could result in enhanced stripping of the envelopes of red giant stars. Linear theory accounts only for orbits whose apsides circulate. The non-linear theory of adiabatic capture into resonance is needed to understand orbits whose apsides librate. The mechanism is a generic dynamical process, and it may be common in galactic nuclei.

New discovery: Quantization of atomic and nuclear rest mass differences

International Nuclear Information System (INIS)

Gareev, F. A.; Zhidkova, I. E.

2007-01-01

We come to the conclusion that all atomic models based on either the Newton equation and the Kepler laws, or the Maxwell equations, or the Schrodinger and Dirac equations are in reasonable agreement with experimental data. We can only suspect that these equations are grounded on the same fundamental principle(s) which is (are) not known or these equations can be transformed into each other. We proposed a new mechanism of LENR: cooperative processes in the whole system - nuclei + atoms + condensed matter - nuclear reactions in plasma - can occur at smaller threshold energies than the corresponding ones on free constituents. We were able to quantize [1] phenomenologically the first time the differences between atomic and nuclear rest masses by the formula: ΔΔ M = n 1 /n 2 x 0.0076294 (in MeV/c 2 ), n i =1,2,3,... Note that this quantization rule is justified for atoms and nuclei with different A, N and Z and the nuclei and atoms represent a coherent synchronized open systems - a complex of coupled oscillators (resonators). The cooperative resonance synchronization mechanisms are responsible for explanation of how the electron volt world can influence on the nuclear mega electron volt world. It means that we created new possibilities for inducing and controlling nuclear reactions by atomic processes grounded on the fundamental low of physics - conservation law of energy. The results of these research fields can provide new ecologically pure mobile sources of energy independent from oil, gas and coal, new substances, and technologies. For example, this discovery gives us a simple and cheep method for utilization of nuclear waste. References [1] F.A. Gareev, I.E. Zhidkova, E-print arXiv Nucl-th/0610002 2006

Secondary-ion mass spectrometry: some applications in the analysis of nuclear material

International Nuclear Information System (INIS)

Christie, W.H.; Eby, R.E.; Warmack, R.J.; Landau, L.

1981-01-01

Secondary ion mass spectrometry (SIMS) has been shown to offer some significant advantages over conventional mass spectrometry for the analysis of radioactive samples. We have used SIMS for the rapid, accurate analysis of B, Li, Cs, U and Pu in various nuclear materials. In many instances, SIMS allows one to perform mass and isotopic analysis on samples that are not amenable to other mass spectrometric techniques (e.g., surface ionization, electron impact, etc.). The significant advantage that accrues from the use of SIMS for isotopic analysis of these materials is the cmplete elimination of any chemical sample preparation steps, and only sample dissolution is necessary for the application of isotope dilution methods for quantitative analysis. The high sensitivity of SIMS for B, Li, U and Pu makes it possible to analyze sufficiently small radioactive samples so that radiation is reduced to acceptable levels for safe handling. The precision of SIMS isotopic analysis for natural B samples is about 0.5% and is about 1% for natural Li samples

Gamow-Teller strength in deformed nuclei within self-consistent pnQRPA with the Gogny force

Directory of Open Access Journals (Sweden)

Martini M.

2014-03-01

Full Text Available In recent years fully consistent quasiparticle random-phase approximation (QRPA calculations using finite range Gogny force have been performed to study electromagnetic excitations of several axially-symmetric deformed nuclei up to the 238U. Here we present the extension of this approach to the charge-exchange nuclear excitations (pn-QRPA. In particular we focus on the Gamow-Teller (GT excitations. A comparison of the predicted GT strength distribution with existing experimental data is presented The role of nuclear deformation is shown. Special attention is paid to β-decay half-lives calculations for which experimental data exist.

Measurement of particle size distribution and mass concentration of nuclear fuel aerosols

International Nuclear Information System (INIS)

Pickering, S.

1982-01-01

The particle size distribution and particle mass concentration of a nuclear fuel aerosol is measured by admitting the aerosol into a vertically-extending container, positioning an alpha particle detector within the container so that its window is horizontal and directed vertically, stopping the admission of aerosol into the container, detecting the alpha-activity of the particles of the aerosol sedimenting onto the detector window (for example in a series of equal time intervals until a constant level is reached), and converting the alpha-activity measurements into particle size distribution and/or particle mass concentration measurements. The detector is attached to a pivotted arm and by raising a counterweight can be lowered from the container for cleaning. (author)

Deformation mechanisms in the San Andreas Fault zone - a comparison between natural and experimentally deformed microstructures

Science.gov (United States)

van Diggelen, Esther; Holdsworth, Robert; de Bresser, Hans; Spiers, Chris

2010-05-01

foliation, lens-like features, micro-folding and occasional indicators of cataclasis and pressure solution in porphyroclasts. Within Core interval 3, deformation appears to be strongly localized in this foliated fault gouge, while rocks outside the gouge have experienced far less deformation. Also Core interval 2 contains a foliated fault gouge which is correlated to a zone of borehole casing deformation. The gouge looks almost identical to the foliated fault gouge in Core interval 3. However, in this core interval the rocks surrounding the actively creeping zone show ample evidence for micro-folding, foliation development, development of anastomosing shear bands, gouge formation, veining, and reworking of earlier formed microstructures. Further, evidence is widespread for cataclasis, pressure solution and reaction of feldspar to form phyllosilicates. Deformation in this core interval is not purely localized in the phyllosilicate-rich, foliated fault gouge, like in Core interval 3, but clearly affects the surrounding rocks as well. The microstructures of the actively creeping zones are very similar, but the surrounding lithologies are different. This difference in lithology probably causes the difference in deformation behaviour between core intervals 2 and 3. Comparison of the SAF microstructures with microstructures obtained from various experimentally deformed phyllosilicate-rich fault gouges shows many similarities. The similarities include microstructures indicating pressure solution, alteration, foliation development, cataclasis, plastic deformation and lens formation. We therefore infer that the deformation mechanisms identified in the experimental samples are the same as the mechanisms controlling deformation in the actively deforming strands of the SAF, pointing to slip on phyllosilicate foliation accommodated by plastic deformation of intervening clasts, cataclasis and occasionally mass transfer processes.

Deformed special relativity with an invariant minimum speed and its ...

Indian Academy of Sciences (India)

On the other hand, according to special relativity (SR), the momentum cannot ... Deformed special relativity with an invariant minimum speed ..... However, we need to show that there is an anti-gravitational interaction between the ordinary proof mass m and the big sphere with a 'dark mass' of vacuum (MΛ), but let us first ...

Realistic soft tissue deformation strategies for real time surgery simulation.

Science.gov (United States)

Shen, Yunhe; Zhou, Xiangmin; Zhang, Nan; Tamma, Kumar; Sweet, Robert

2008-01-01

A volume-preserving deformation method (VPDM) is developed in complement with the mass-spring method (MSM) to improve the deformation quality of the MSM to model soft tissue in surgical simulation. This method can also be implemented as a stand-alone model. The proposed VPDM satisfies the Newton's laws of motion by obtaining the resultant vectors form an equilibrium condition. The proposed method has been tested in virtual surgery systems with haptic rendering demands.

Gamow-Teller decay and nuclear deformation: implementing of a new total absorption spectrometer, study of isotopes N {approx_equal} Z krypton and strontium; Decroissance Gamow-Teller et deformation nucleaire: mise en oeuvre d'un nouveau spectrometre a absorption totale, etude d'isotopes N {approx_equal} Z de krypton et strontium

Energy Technology Data Exchange (ETDEWEB)

Poirier, E

2002-12-01

Nuclei with A {approx} 70 along the N=Z line are known to be the scene of phenomena closely related to the nuclear deformation and are of particular interest since theoretical mean field calculations predict that a large part of the Gamow-Teller resonance might be located below the ground state of the mother nucleus and then be accessible through {beta}-decay studies. These results have shown the effect of the shape of the ground state on the intensity of the Gamow-Teller strength. Thus, the experimental determination, through {delta}-decay, of the Gamow-Teller strength distribution and the comparison to the theoretical predictions allow to pin down the quadrupolar deformation parameter of the ground state of the parent nucleus. In order to study the neutron deficient isotopes of krypton (A=72,73,74,75) and strontium (A=76,77,78) and to establish the {beta}-strength on the full energy range, a new total absorption spectrometer (TAgS) has been built in the frame of an international collaboration and installed at the (SOLDE/CERN mass separator. For the data analysis, the response function R of the spectrometer has been calculated by means of Monte-Carlo simulations, based on the GEANT4 code, and of a statistical description of the level scheme in the daughter nucleus. The {beta}-feeding distribution has been obtained from experimental spectra through a method based on Bayes theorem and then converted into Gamow-Teller strength. The results coming from the {sup 74}Kr decay analysis allow to describe the ground state of such a nucleus as the coexistence of an oblate shape and of a prolate shape. In the case of {sup 76}Sr, the experimental Gamow-Teller strength distribution strongly indicates a prolate deformation. (author)

Photon strength in spherical and deformed heavy nuclei

International Nuclear Information System (INIS)

Grosse, E.; Junghans, A.; Birgersson, E.; Massarczyk, R.; Schramm, G.; Becvar, F.

2010-01-01

Information on the photon strength in heavy nuclei with mass A>150 will be given and compared to respective data. The photon strength function is a very important ingredient for statistical model calculations - especially when these are used to describe neutron capture. Several schemes for a transmutation of radioactive waste favor nuclear reactions with fast neutrons and these also influence the performance of various reactor types proposed to deliver nuclear energy together with only small quantities of such waste. Reactions with fast neutrons are far less studied as compared to those induced by thermal neutrons. As they are not easily accessible experimentally, reference is often made to calculations using the statistical model. Photon emission probabilities are needed as input to such calculations aiming for predictions on fission to capture ratios. From the favorable comparison of our parameterization to the experimental data for photon induced as well radiative capture processes in nuclei with various shapes and level densities we conclude what follows. First, the giant dipole resonance has very much the same properties in all heavy nuclei when their deformation is properly accounted for and its spreading width varies only smoothly with the resonance energies E k and not with the photon energy E γ . The radiative neutron capture results presented confirm strength data found in the literature. We also learn that our parameterization is at least a good approximation for photon energies below 4 MeV that dominate this process

Multiple nucleon transfer in damped nuclear collisions. [Lectures, mass charge, and linear and angular momentum transport

Energy Technology Data Exchange (ETDEWEB)

Randrup, J.

1979-07-01

This lecture discusses a theory for the transport of mass, charge, linear, and angular momentum and energy in damped nuclear collisions, as induced by multiple transfer of individual nucleons. 11 references.

Study of octupole deformation in n-rich Ba isotopes populated via $\\beta$-decay

CERN Multimedia

We propose to exploit the unique capability of the ISOLDE facility to produce $^{150, 151, 152}$Cs beams to investigate their radioactive $\\beta$-decay to $^{150, 151, 152}$Ba. The interest to study this mass region is twofold: these nuclei are expected to show octupole deformations already in their low-lying state, secondly information on the $\\beta$-decay is needed for the nuclear astrophysical model. The experiment will be performed with the ISOLDE Decay Station (IDS) setup using the fast tape station of K.U.-Leuven, equipped with four Clover Germanium detectors, four LaBr$_{3}$(Ce) detectors and one LEP HPGe detector. Information on the $\\beta$-decay, such as lifetimes and delayed neutron-emission probabilities, will be extracted, together with the detailed spectroscopy of the daughter nuclei, via $\\gamma$-$\\gamma$-coincidences and lifetime measurement of specific states.

Chiral trace relations in Ω-deformed N=2 theories

Energy Technology Data Exchange (ETDEWEB)

Beccaria, Matteo; Fachechi, Alberto; Macorini, Guido [Dipartimento di Matematica e Fisica Ennio De Giorgi,Università del Salento, Via Arnesano, 73100 Lecce (Italy); INFN - Sezione di LecceVia Arnesano, 73100 Lecce (Italy)

2017-05-04

We consider N=2SU(2) gauge theories in four dimensions (pure or mass deformed) and discuss the properties of the simplest chiral observables in the presence of a generic Ω-deformation. We compute them by equivariant localization and analyze the structure of the exact instanton corrections to the classical chiral ring relations. We predict exact relations valid at all instanton number among the traces 〈Trφ{sup n}〉, where φ is the scalar field in the gauge multiplet. In the Nekrasov-Shatashvili limit, such relations may be explained in terms of the available quantized Seiberg-Witten curves. Instead, the full two-parameter deformation enjoys novel features and the ring relations require non trivial additional derivative terms with respect to the modular parameter. Higher rank groups are briefly discussed emphasizing non-factorization of correlators due to the Ω-deformation. Finally, the structure of the deformed ring relations in the N=2{sup ⋆} theory is analyzed from the point of view of the Alday-Gaiotto-Tachikawa correspondence proving consistency as well as some interesting universality properties.

New estimates of quadrupole deformation β of some nearly spherical even Mo nuclei

International Nuclear Information System (INIS)

Singh, Y.; Gupta, K.K.; Singh, M.; Bihari, Chhail; Varshney, A.K.; Gupta, D.K.

2013-01-01

The deformation parameter β and γ of the collective model of Bohr and Mottelson are basic descriptors of the nuclear equilibrium shape and structure. In recent past the sets of deformation parameters (β, γ) have been extracted from both level energies and E2 transition rates in even Xe, Ba and Ce nuclei and Hf, W, Os, Pt and Hg nuclei using rigid triaxial rotor model of Davydov – Filippov

Approximate Eigensolutions of the Deformed Woods—Saxon Potential via AIM

International Nuclear Information System (INIS)

Ikhdair, Sameer M.; Falaye Babatunde, J.; Hamzavi, Majid

2013-01-01

Using the Pekeris approximation, the Schrödinger equation is solved for the nuclear deformed Woods—Saxon potential within the framework of the asymptotic iteration method. The energy levels are worked out and the corresponding normalized eigenfunctions are obtained in terms of hypergeometric function

Probing deformed orbitals with vector A( vector e, e' N)B reactions

International Nuclear Information System (INIS)

Garrido, E.; Caballero, J.A.; Moya de Guerra, E.; Sarriguren, P.; Udias, J.M.

1995-01-01

We present results for response functions and asymmetries in the nuclear reactions 37 vector Ar( vector e, e' n) 36 Ar and 37 vector K( vector e,e' p) 36 Ar at quasifree kinematics. We compare PWIA results obtained using deformed HF wave functions with PWIA and DWIA results obtained assuming a spherical mean field. We show that the complex structure of the deformed orbitals can be probed by coincidence measurements with polarized beam and targets. ((orig.))

Mass and Elite Views on Nuclear Security: US National Security Surveys 1993-1999

Energy Technology Data Exchange (ETDEWEB)

HERRON,KERRY G.; JENKINS-SMITH,HANK C.; HUGHES,SCOTT D.

2000-06-01

This is the fourth report in an ongoing series of studies examining how US perspectives about nuclear security are evolving in the post-Cold War era. In Volume 1 the authors present findings from a nationwide telephone survey of randomly selected members of the US general public conducted from 13 September to 14 October 1999. Results are compared to findings from previous surveys in this series conducted in 1993, 1995, and 1997, and trends are analyzed. Key areas of investigation reported in Volume 1 include evolving perceptions of nuclear weapons risks and benefits, preferences for related policy and spending issues, and views about three emerging issue areas: deterrent utility of precision guided munitions; response options to attacks in which mass casualty weapons are used; and expectations about national missile defenses. In this volume they relate respondent beliefs about nuclear security to perceptions of nuclear risks and benefits and to policy preferences. They develop causal models to partially explain key preferences, and they employ cluster analysis to group respondents into four policy relevant clusters characterized by similar views and preferences about nuclear security within each cluster. Systematic links are found among respondent demographic characteristics, perceptions of nuclear risks and benefits, policy beliefs, and security policy and spending preferences. In Volume 2 they provide analysis of in-depth interviews with fifty members of the US security policy community.

Mass and Elite Views on Nuclear Security: US National Security Surveys 1993-1999

International Nuclear Information System (INIS)

Herron, Kerry G.; Jenkins-Smith, Hank C.; Hughes, Scott D.

2000-01-01

This is the fourth report in an ongoing series of studies examining how US perspectives about nuclear security are evolving in the post-Cold War era. In Volume 1 the authors present findings from a nationwide telephone survey of randomly selected members of the US general public conducted from 13 September to 14 October 1999. Results are compared to findings from previous surveys in this series conducted in 1993, 1995, and 1997, and trends are analyzed. Key areas of investigation reported in Volume 1 include evolving perceptions of nuclear weapons risks and benefits, preferences for related policy and spending issues, and views about three emerging issue areas: deterrent utility of precision guided munitions; response options to attacks in which mass casualty weapons are used; and expectations about national missile defenses. In this volume they relate respondent beliefs about nuclear security to perceptions of nuclear risks and benefits and to policy preferences. They develop causal models to partially explain key preferences, and they employ cluster analysis to group respondents into four policy relevant clusters characterized by similar views and preferences about nuclear security within each cluster. Systematic links are found among respondent demographic characteristics, perceptions of nuclear risks and benefits, policy beliefs, and security policy and spending preferences. In Volume 2 they provide analysis of in-depth interviews with fifty members of the US security policy community

Weapons of mass destruction: Overview of the CBRNEs (Chemical, Biological, Radiological, Nuclear, and Explosives).

Science.gov (United States)

Prockop, Leon D

2006-11-01

The events of September 11, 2001, made citizens of the world acutely aware of disasters consequent to present-day terrorism. This is a war being waged for reasons obscure to many of its potential victims. The term "NBCs" was coined in reference to terrorist weapons of mass destruction, i.e., nuclear, biological and chemical. The currently accepted acronym is "CBRNE" which includes Chemical, Biological, Radiological, Nuclear, and Explosive weapons. Non-nuclear explosives are the most common terrorist weapon now in use. Nuclear and radiological weapons are beyond the scope of this publication, which focuses on the "CBEs", i.e. chemical, biological and explosive weapons. Although neurologists will not be the first responders to CBEs, they must know about the neurological effects in order to provide diagnosis and treatment to survivors. Neurological complications of chemical, biological and explosive weapons which have or may be used by terrorists are reviewed by international experts in this publication. Management and treatment profiles are outlined.

Chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade mixed oxides [(U,Pu)O2

International Nuclear Information System (INIS)

Anon.

1981-01-01

Mixed oxide, a mixture of uranium and plutonium oxides, is used as a nuclear-reactor fuel in the form of pellets. The plutonium content may be up to 10 wt %, and the diluent uranium may be of any U-235 enrichment. In order to be suitable for use as a nuclear fuel, the material must meet certain criteria for combined uranium and plutonium content, effective fissile content, and impurity content. Analytical procedures used to determine if mixed oxides comply with specifications are: uranium by controlled-potential coulometry; plutonium by controlled-potential coulometry; plutonium by amperometric titration with iron (II); nitrogen by distillation spectrophotometry using Nessler reagent; carbon (total) by direct combustion-thermal-conductivity; total chlorine and fluorine by pyrohydrolysis; sulfur by distillation-spectrophotometry; moisture by the coulometric, electrolytic moisture analyzer; isotopic composition by mass spectrometry; rare earths by copper spark spectroscopy; trace impurities by carrier distillation spectroscopy; impurities by spark-source mass spectrography; total gas in reactor-grade mixed dioxide pellets; tungsten by dithiol-spectrophotometry; rare earth elements by spectroscopy; plutonium-238 isotopic abundance by alpha spectrometry; uranium and plutonium isotopic analysis by mass spectrometry; oxygen-to-metal atom ratio by gravimetry

Development of a deformable dosimetric phantom to verify dose accumulation algorithms for adaptive radiotherapy.

Science.gov (United States)

Zhong, Hualiang; Adams, Jeffrey; Glide-Hurst, Carri; Zhang, Hualin; Li, Haisen; Chetty, Indrin J

2016-01-01

Adaptive radiotherapy may improve treatment outcomes for lung cancer patients. Because of the lack of an effective tool for quality assurance, this therapeutic modality is not yet accepted in clinic. The purpose of this study is to develop a deformable physical phantom for validation of dose accumulation algorithms in regions with heterogeneous mass. A three-dimensional (3D) deformable phantom was developed containing a tissue-equivalent tumor and heterogeneous sponge inserts. Thermoluminescent dosimeters (TLDs) were placed at multiple locations in the phantom each time before dose measurement. Doses were measured with the phantom in both the static and deformed cases. The deformation of the phantom was actuated by a motor driven piston. 4D computed tomography images were acquired to calculate 3D doses at each phase using Pinnacle and EGSnrc/DOSXYZnrc. These images were registered using two registration software packages: VelocityAI and Elastix. With the resultant displacement vector fields (DVFs), the calculated 3D doses were accumulated using a mass-and energy congruent mapping method and compared to those measured by the TLDs at four typical locations. In the static case, TLD measurements agreed with all the algorithms by 1.8% at the center of the tumor volume and by 4.0% in the penumbra. In the deformable case, the phantom's deformation was reproduced within 1.1 mm. For the 3D dose calculated by Pinnacle, the total dose accumulated with the Elastix DVF agreed well to the TLD measurements with their differences <2.5% at four measured locations. When the VelocityAI DVF was used, their difference increased up to 11.8%. For the 3D dose calculated by EGSnrc/DOSXYZnrc, the total doses accumulated with the two DVFs were within 5.7% of the TLD measurements which are slightly over the rate of 5% for clinical acceptance. The detector-embedded deformable phantom allows radiation dose to be measured in a dynamic environment, similar to deforming lung tissues, supporting

Development of a deformable dosimetric phantom to verify dose accumulation algorithms for adaptive radiotherapy

Directory of Open Access Journals (Sweden)

Hualiang Zhong

2016-01-01

Full Text Available Adaptive radiotherapy may improve treatment outcomes for lung cancer patients. Because of the lack of an effective tool for quality assurance, this therapeutic modality is not yet accepted in clinic. The purpose of this study is to develop a deformable physical phantom for validation of dose accumulation algorithms in regions with heterogeneous mass. A three-dimensional (3D deformable phantom was developed containing a tissue-equivalent tumor and heterogeneous sponge inserts. Thermoluminescent dosimeters (TLDs were placed at multiple locations in the phantom each time before dose measurement. Doses were measured with the phantom in both the static and deformed cases. The deformation of the phantom was actuated by a motor driven piston. 4D computed tomography images were acquired to calculate 3D doses at each phase using Pinnacle and EGSnrc/DOSXYZnrc. These images were registered using two registration software packages: VelocityAI and Elastix. With the resultant displacement vector fields (DVFs, the calculated 3D doses were accumulated using a mass-and energy congruent mapping method and compared to those measured by the TLDs at four typical locations. In the static case, TLD measurements agreed with all the algorithms by 1.8% at the center of the tumor volume and by 4.0% in the penumbra. In the deformable case, the phantom's deformation was reproduced within 1.1 mm. For the 3D dose calculated by Pinnacle, the total dose accumulated with the Elastix DVF agreed well to the TLD measurements with their differences <2.5% at four measured locations. When the VelocityAI DVF was used, their difference increased up to 11.8%. For the 3D dose calculated by EGSnrc/DOSXYZnrc, the total doses accumulated with the two DVFs were within 5.7% of the TLD measurements which are slightly over the rate of 5% for clinical acceptance. The detector-embedded deformable phantom allows radiation dose to be measured in a dynamic environment, similar to deforming lung

A two-dimensional deformable phantom for quantitatively verifying deformation algorithms

Energy Technology Data Exchange (ETDEWEB)

Kirby, Neil; Chuang, Cynthia; Pouliot, Jean [Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143-1708 (United States)

2011-08-15

Purpose: The incorporation of deformable image registration into the treatment planning process is rapidly advancing. For this reason, the methods used to verify the underlying deformation algorithms must evolve equally fast. This manuscript proposes a two-dimensional deformable phantom, which can objectively verify the accuracy of deformation algorithms, as the next step for improving these techniques. Methods: The phantom represents a single plane of the anatomy for a head and neck patient. Inflation of a balloon catheter inside the phantom simulates tumor growth. CT and camera images of the phantom are acquired before and after its deformation. Nonradiopaque markers reside on the surface of the deformable anatomy and are visible through an acrylic plate, which enables an optical camera to measure their positions; thus, establishing the ground-truth deformation. This measured deformation is directly compared to the predictions of deformation algorithms, using several similarity metrics. The ratio of the number of points with more than a 3 mm deformation error over the number that are deformed by more than 3 mm is used for an error metric to evaluate algorithm accuracy. Results: An optical method of characterizing deformation has been successfully demonstrated. For the tests of this method, the balloon catheter deforms 32 out of the 54 surface markers by more than 3 mm. Different deformation errors result from the different similarity metrics. The most accurate deformation predictions had an error of 75%. Conclusions: The results presented here demonstrate the utility of the phantom for objectively verifying deformation algorithms and determining which is the most accurate. They also indicate that the phantom would benefit from more electron density heterogeneity. The reduction of the deformable anatomy to a two-dimensional system allows for the use of nonradiopaque markers, which do not influence deformation algorithms. This is the fundamental advantage of this

Direct mass measurements of 100Sn and magic nuclei near the N=Z line

International Nuclear Information System (INIS)

Chartier, M.

1996-01-01

The masses of nuclei far from stability are of particular interest in nuclear structure studies, and many methods of varying precision have been developed to undertake their measurement. A direct time of flight technique in conjunction with the SPEG spectrometer at GANIL has been extended to the mass measurement of proton-rich nuclei near N = Z line in the mass region A ≅ 60-80 known to provide input for astrophysical modelling of the rp-process and information relevant to the nuclear structure in a region of high deformation. The radioactive beams were produced via the fragmentation of a 78 Kr beam on a nat Ni target, using the new SISSI device. A purification method based on the stripping of the secondary ions was successfully used for the first time, and the masses of 70 Se and 71 Se were measured. In order to improve the mass resolution for heavier nuclei, another method using the second cyclotron of GANIL (CSS2) as a high resolution spectrometer has been developed. An experiment aimed at measuring the masses of A 100 isobars in the vicinity of the doubly magic nucleus 100 Sn was successfully performed, using this original technique. Secondary ions of 100 Ag, 100 Cd, 100 In and 100 Sn produced via fusion-evaporation reaction 50 Cr + 58 Ni and simultaneously accelerated in the CSS2 cyclotron. The mass of 100 Cd and, for the first time, the masses of 100 Sn were determined directly with respect to the reference mass of 100 Ag. These results have been compared to various theoretical predictions and open the discussion on considerations of spin-isospin symmetry. (author)

A Bed-Deformation Experiment Beneath Engabreen, Norway

Science.gov (United States)

Iverson, N. R.; Hooyer, T. S.; Fischer, U. H.; Cohen, D.; Jackson, M.; Moore, P. L.; Lappegard, G.; Kohler, J.

2001-12-01

Although deformation of sediment beneath ice masses may contribute to their motion and may sometimes enable fast glacier flow, both the kinematics and mechanics of deformation are controversial. This controversy stems, in part, from subglacial measurements that are difficult to interpret. Measurements have been made either beneath ice margins or remotely through boreholes with interpretive limitations caused by uncertain instrument position and performance, uncertain sediment thickness and bed geometry, and unknown disturbance of the bed and stress state by drilling. We have used a different approach made possible by the Svartisen Subglacial Laboratory, which enables human access to the bed of Engabreen, Norway, beneath 230 m of temperate ice. A trough (2 m x 1.5 m x 0.4 m deep) was blasted in the rock bed and filled with sediment (75 percent sand and gravel, 20 percent silt, 5 percent clay). Instruments were placed in the sediment to record shear deformation (tiltmeters), dilation and contraction, total normal stress, and pore-water pressure. Pore pressure was manipulated by feeding water to the base of the sediment with a high-pressure pump, operated in a rock tunnel 4 m below the bed surface. After irregular deformation during closure of ice on the sediment, shear deformation and volume change stopped, and total normal stress became constant at 2.2 MPa. Subsequent pump tests, which lasted several hours, induced pore-water pressures greater than 70 percent of the total normal stress and resulted in shear deformation over most of the sediment thickness with attendant dilation. Ice separated from the sediment when effective normal stress was lowest, arresting shear deformation. Displacement profiles during pump tests were similar to those observed by Boulton and co-workers at Breidamerkurjökull, Iceland, with rates of shear strain increasing upward toward the glacier sole. Such deformation does not require viscous deformation resistance and is expected in a

Standard test methods for chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide (Gd2O3) powder

CERN Document Server

American Society for Testing and Materials. Philadelphia

2006-01-01

1.1 These test methods cover procedures for the chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide powders to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Carbon by Direct CombustionThermal Conductivity C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Total Chlorine and Fluorine by Pyrohydrolysis Ion Selective Electrode C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Loss of Weight on Ignition 7-13 Sulfur by CombustionIodometric Titration Impurity Elements by a Spark-Source Mass Spectrographic C761 Test Methods for Chemical, Mass Spectrometric, Spectrochemical,Nuclear, and Radiochemical Analysis of Uranium Hexafluoride C1287 Test Method for Determination of Impurities In Uranium Dioxide By Inductively Coupled Plasma Mass Spectrometry Gadolinium Content in Gadolinium Oxid...

Bimodality in macroscopic dynamics of nuclear fission

International Nuclear Information System (INIS)

Bastrukov, S.I.; Salamatin, V.S.; Strteltsova, O.I.; Molodtsova, I.V.; Podgainy, D.V.; )

2000-01-01

The elastodynamic collective model of nuclear fission is outlined whose underlying idea is that the stiff structure of nuclear shells imparts to nucleus properties typical of a small piece of an elastic solid. Emphasis is placed on the macroscopic dynamics of nuclear deformations resulting in fission by two energetically different modes. The low-energy S-mode is the fission due to disruption of elongated quadrupole spheroidal shape. The characteristic features of the high-energy T-mode of division by means of torsional shear deformations is the compact scission configuration. Analytic and numerical estimates for the macroscopic fission-barrier heights are presented, followed by discussion of fingerprints of the above dynamical bimodality in the available data [ru

Deformation mechanisms in ferritic/martensitic steels and the impact on mechanical design

International Nuclear Information System (INIS)

Ghoniem, Nasr M.; Po, Giacomo; Sharafat, Shahram

2013-01-01

Structural steels for nuclear applications have undergone rapid development during the past few decades, thanks to a combination of trial-and-error, mechanism-based optimization, and multiscale modeling approaches. Deformation mechanisms are shown to be intimately related to mechanical design via dominant plastic deformation modes. Because mechanical design rules are mostly based on failure modes associated with plastic strain damage accumulation, we present here the fundamental deformation mechanisms for Ferritic/Martensitic (F/M) steels, and delineate their operational range of temperature and stress. The connection between deformation mechanisms, failure modes, and mechanical design is shown through application of design rules. A specific example is given for the alloy F82H utilized in the design of a Test Blanket Module (TBM) in the International Thermonuclear Experimental Reactor (ITER), where several constitutive equations are developed for design-related mechanical properties

Deformation mechanisms in ferritic/martensitic steels and the impact on mechanical design

Energy Technology Data Exchange (ETDEWEB)

Ghoniem, Nasr M., E-mail: ghoniem@seas.ucla.edu; Po, Giacomo; Sharafat, Shahram

2013-10-15

Structural steels for nuclear applications have undergone rapid development during the past few decades, thanks to a combination of trial-and-error, mechanism-based optimization, and multiscale modeling approaches. Deformation mechanisms are shown to be intimately related to mechanical design via dominant plastic deformation modes. Because mechanical design rules are mostly based on failure modes associated with plastic strain damage accumulation, we present here the fundamental deformation mechanisms for Ferritic/Martensitic (F/M) steels, and delineate their operational range of temperature and stress. The connection between deformation mechanisms, failure modes, and mechanical design is shown through application of design rules. A specific example is given for the alloy F82H utilized in the design of a Test Blanket Module (TBM) in the International Thermonuclear Experimental Reactor (ITER), where several constitutive equations are developed for design-related mechanical properties.

Accelerator Mass Spectrometry at the National Institute of Nuclear Physics and Engineering in Bucharest

International Nuclear Information System (INIS)

Stan-Sion, C.; Catana, D.; Plostinaru, D.; Radulescu, M.; Enachescu, M.; Ivascu, M.; Marinescu, L.; Dima, R.

2000-01-01

The Accelerator Mass Spectrometry (AMS) is today the experimental physical method capable to measure the lowest concentration of a particular nuclide in a sample material. Ratios of radionuclides in the range 10 -13 - 10 -15 are normally measured with this technique, corresponding to a sensitivity which makes possible the detection of only 1 Atom in a surrounding material of about 1 Million of Billions of other Atoms. Thus, the AMS has advanced the art of Classical Mass Spectrometry (sensitivity 10 -11 ) to a sensitivity which allows for the first time the performance of special applications in environmental physics, medicine, pharmacology, geology, archaeology, measurements of radio nuclides in the Earth's atmosphere produced by cosmic-rays or by nuclear power plants, applications in astrophysics and in nuclear physics.An Accelerator Mass Spectrometry facility was constructed at the FN - 8 MV tandem accelerator of the National Institute of Physics and Nuclear Engineering . The construction was possible in the frame of a co-operation with the Technical University Munich and with financial support from IAEA-Vienna. It represents the first experimental set-up of this type in the large geographical area of Eastern Europe. The main components of the facility are: the ion injector deck, the AMS beam line and the detector systems. The injector deck is polarized at 50 kV and contains the high current sputtering ion source (spherical ionizer) followed, for beam transport, by electrostatic devices (single lenses, steerers, quadrupole lenses) a double focussing, 90 angle analyzing magnet (Danfysik), a pre-acceleration tube (NEC) and several diagnose and defining elements. The AMS samples are placed in an eight-stack magazine attached to the ion source. On the exit side of the tandem accelerator tank, a velocity filter and the particle detection system are mounted. The beam line, on the high-energy side, is optically achromatic and contains two 90 angle analyzing magnets of

Deformation and clustering in even-Z nuclei up to Mg studied using AMD with the Gogny force

Energy Technology Data Exchange (ETDEWEB)

Kimura, Masaaki; Sugawa, Yoshio; Horiuchi, Hisashi [Kyoto Univ. (Japan). Dept. of Physics

2001-12-01

Employing the Gogny force as an effective force, we study the ground state properties of light nuclei using antisymmetrized molecular dynamics (AMD). In a previous paper, we discussed the nuclear binding energies and nuclear radii of He, Be, C, O, Ne and Mg isotopes. In this paper, we mainly consider the deformation properties and the clustering nature of these isotopes. By comparing the calculated results with the AMD results by use of the Skyrme-III (SIII) force, we investigated the differences and similarities between the SIII force and the Gogny force. We find that the Gogny force yields rather better binding energy and larger deformation than the SIII force. We carry out the parity-projected calculations. Parity projection enhances the parity-violating deformation and the cluster structure of certain nuclei. Shape of the deformation energy surface is also changed by parity projection. This causes a competition between the mean-field-like structure and the cluster-like structure. A modified version of AMD, which employs deformed Gaussian wave packets instead of spherical ones, is shown to give large quadrupole moments in the case of Mg isotopes. (author)

Deformation and clustering in even-Z nuclei up to Mg studied using AMD with the Gogny force

International Nuclear Information System (INIS)

Kimura, Masaaki; Sugawa, Yoshio; Horiuchi, Hisashi

2001-01-01

Employing the Gogny force as an effective force, we study the ground state properties of light nuclei using antisymmetrized molecular dynamics (AMD). In a previous paper, we discussed the nuclear binding energies and nuclear radii of He, Be, C, O, Ne and Mg isotopes. In this paper, we mainly consider the deformation properties and the clustering nature of these isotopes. By comparing the calculated results with the AMD results by use of the Skyrme-III (SIII) force, we investigated the differences and similarities between the SIII force and the Gogny force. We find that the Gogny force yields rather better binding energy and larger deformation than the SIII force. We carry out the parity-projected calculations. Parity projection enhances the parity-violating deformation and the cluster structure of certain nuclei. Shape of the deformation energy surface is also changed by parity projection. This causes a competition between the mean-field-like structure and the cluster-like structure. A modified version of AMD, which employs deformed Gaussian wave packets instead of spherical ones, is shown to give large quadrupole moments in the case of Mg isotopes. (author)

Octupole Deformed Nuclei in the Actinide Region

CERN Multimedia

Thorsteinsen, T; Rubio barroso, B; Simpson, J; Gulda, K; Sanchez-vega, M; Cocks, J; Nybo, K; Garcia borge, M; Aas, A; Fogelberg, B; Honsi, J; Smith, G; Naumann, R; Grant, I

2002-01-01

The aim of the present study is to investigate the limits of the "island" of octupole deformation in the mass region A=225. It is of particular importance to demonstrate experimentally the sudden disappearance of the stable octupole deformation in the presence of a well developed quadrupole field. \\\\ \\\\In order to establish the upper border line the $\\beta$ -decay chains of $^{227}$Rn $\\rightarrow ^{227}$Fr $\\rightarrow ^{227}$Ra and $^{231}$Fr $\\rightarrow ^{231}$Ra $\\rightarrow ^{231}$Ac were studied at PSB-ISOLDE using advanced fast timing and $\\gamma$-ray spectroscopy techniques. The lifetimes of the excited states have been measured in the picosecond range using the time-delayed $\\beta\\gamma\\gamma$(t) method.

Radiocarbon Mass Balance for a Magnox Nuclear Power Station

International Nuclear Information System (INIS)

Metcalfe, M.P.; Mills, R.W.

2016-01-01

Nuclear power generation in the United Kingdom is based principally on graphite-moderated gas-cooled reactors. The mass of irradiated graphite associated with these reactors, including material from associated experimental, prototype and production reactors, exceeds 96,000 tonnes. One of the principal long-lived radionuclides produced during graphite irradiation is radiocarbon (C-14), which has a half-life of 5730 ± 40 years. Decommissioning and graphite waste management strategies must take account of this radionuclide. In order to identify appropriate options for addressing the potential hazard of C-14, it is important that the production processes are understood and the distributions and concentrations of C-14 are characterised. In fact, C-14 precursors and their activation processes are well-known. However, there is ongoing debate over the relative importance of different C-14 precursors, which will determine the location of C-14 within graphite components and hence its mobility/response to treatment. A generally held misconception concerning C-14 in irradiated graphite is that generic statements can be made about its precursors and their location. C-14 location and activities will depend upon the composition of the original manufactured graphite (raw materials, impurities), the chemical environment of the graphite during service and the irradiation history of the graphite. So, while there may be some similarities across, for example, carbon dioxide cooled graphite moderated designs (Magnox, AGR, UNGG), any informed assessment of a core’s C-14 inventory would require more-precise characterisation. The analysis presented here focuses on a UK Magnox reactor core, Reactor 1 at Wylfa Nuclear Power Station. The objective of the analysis is to present a full C-14 mass balance over a selected period of operation for which there are accurate C-14 discharge records. The analysis presented here provides the first assessment of the principal C-14 activation pathways

Experimental studies of the deformation of carbonated rocks by dissolution crystallization under stress

International Nuclear Information System (INIS)

Zubtsov, Sergey

2003-01-01

The first part of this research thesis reports the experimental investigation and the modelling of the deformation of poly-mineral rocks under the influence of mechanism of dissolution-crystallization under stress. This mechanism has a significant role in the compaction of sedimentary rocks, in the folding process of the earth's crust. The author notably reports the results of the experimental deformation of calcite in presence of water (calcite is present in marls in which the deposit of nuclear wastes in planned in France). The second part deals with the fact that healing is possible between two grains of similar mineralogy, and slows down or even stops deformation

Effective mass of a #betta#-particle in nuclear matter and OBE #betta#-n interactions

International Nuclear Information System (INIS)

Bando, Hiroharu; Nagata, Sinobu.

1982-01-01

The effective mass of a lambda particle (M sub( lambda )*) in nuclear matter is investigated within the framework of the lowest-order Brueckner theory by employing the Nijmegen OBE lambda -N interaction model D and F. The non-locality mass (M tilde sub( lamda )) and the energy mass (anti M sub( lambda )) are evaluated and discussed in the light of the characteristics of the two models. In comparison with the model D, the model F yields smaller anti M sub( lambda ) and larger anti M sub( lamb da ) reflecting the stronger Majorana exchange force and the stronger lambda N- sigma N coupling tensor force. Final results of M sub( lambda )*/M sub( lambda ) are 0.85 for D and 0.79 for F. In view of the effective lambda mass inferred from observed properties of the single particle potential for lambda , the model D interaction seems to be more adequate. (author)

Nuclear spectroscopy in nuclei with Z ≥ 110

Energy Technology Data Exchange (ETDEWEB)

Ackermann, D., E-mail: D.Ackermann@gsi.de

2015-12-15

The nuclear structure of species at the extreme of highest atomic numbers Z and nuclear masses A promises to reveal intriguing new features of this exotic hadronic matter. Their stability itself they owe to quantum-mechanic effects only. They form metastable states which, governed by the subtle interplay of α decay and spontaneous fission versus quantum-mechanic stabilization via shell effects, are in some cases more robust against disintegration than their ground states. Following the isotopic and isotonic trends of single particle levels, as well as collective features like deformation, may reveal the path towards the gap in the level densities, expected for the next closed proton and neutron shells at the so-called “island of stability” of spherical superheavy nuclei. Their atomic configuration offers via X-ray spectroscopy a tool to identify the atomic number of heavy species, where other more traditional methods like evaporation residue (ER)–α correlation are not applicable.

Storage of plutonium and nuclear power plant actinide waste in the form of critical-mass-free ceramics containing neutron poisons

Energy Technology Data Exchange (ETDEWEB)

Nadykto, B.A. [RFNC-VNIIEF, Nizhni Novgorod Region (Russian Federation)

2001-07-01

The nuclear weapons production has resulted in accumulation of a large quantity of plutonium and uranium highly enriched with uranium-235 isotope (many tons). The work under ISTC Project 332B-97 treated the issues of safe plutonium storage through making critical-mass-free plutonium oxide compositions with neutron poisons. This completely excludes immediate utilization (without chemical reprocessing) of retained plutonium in nuclear devices. It is therewith possible to locate plutonium most compactly in the storage facility, which would allow reduction in required storage areas and costs. The issues of the surplus weapon-grade plutonium management and utilization have been comprehensively studied in the recent decade. The issues are treated in multiple scientific publications, conferences, and seminars. At the same time, issues of nuclear power engineering actinide waste storage are studied no less extensively. The general issues are material radioactivity and energy release and nuclear accident hazards due to critical mass generation. Plutonium accumulated in nuclear power plant spent fuel is more accessible than weapon-grade plutonium and can become of higher and higher interest with time as its activity reduces, including as material for nuclear devices. The urgency of plutonium management is presently related not only to accumulation of surplus weapon-grade plutonium, but also to the fact that it is high time to decide what has to be done regarding reactor plutonium. Presently, the possibility of actinide separation from NPP spent nuclear fuel and compact underground burial separately from other (mainly fragment) activity is being considered. Actinide and neutron poison base critical-mass-free ceramic materials (similar to plutonium ceramics) may be useful for this burial method. (author)

Storage of plutonium and nuclear power plant actinide waste in the form of critical-mass-free ceramics containing neutron poisons

International Nuclear Information System (INIS)

Nadykto, B.A.

2001-01-01

The nuclear weapons production has resulted in accumulation of a large quantity of plutonium and uranium highly enriched with uranium-235 isotope (many tons). The work under ISTC Project 332B-97 treated the issues of safe plutonium storage through making critical-mass-free plutonium oxide compositions with neutron poisons. This completely excludes immediate utilization (without chemical reprocessing) of retained plutonium in nuclear devices. It is therewith possible to locate plutonium most compactly in the storage facility, which would allow reduction in required storage areas and costs. The issues of the surplus weapon-grade plutonium management and utilization have been comprehensively studied in the recent decade. The issues are treated in multiple scientific publications, conferences, and seminars. At the same time, issues of nuclear power engineering actinide waste storage are studied no less extensively. The general issues are material radioactivity and energy release and nuclear accident hazards due to critical mass generation. Plutonium accumulated in nuclear power plant spent fuel is more accessible than weapon-grade plutonium and can become of higher and higher interest with time as its activity reduces, including as material for nuclear devices. The urgency of plutonium management is presently related not only to accumulation of surplus weapon-grade plutonium, but also to the fact that it is high time to decide what has to be done regarding reactor plutonium. Presently, the possibility of actinide separation from NPP spent nuclear fuel and compact underground burial separately from other (mainly fragment) activity is being considered. Actinide and neutron poison base critical-mass-free ceramic materials (similar to plutonium ceramics) may be useful for this burial method. (author)

Orientation sensitive deformation in Zr alloys: experimental and modeling studies

International Nuclear Information System (INIS)

Srivastava, D.; Keskar, N.; Manikrishna, K.V.; Dey, G.K.; Jha, S.K.; Saibaba, N.

2016-01-01

Zirconium alloys are used for fuel cladding and other structural components in pressurised heavy water nuclear reactors (PHWR's). Currently there is a lot of interest in developing alloys for structural components for higher temperature reactor operation. There is also need for development of cladding material with better corrosion and mechanical property of cladding material for higher and extended burn up applications. The performance of the cladding material is primarily influenced by the microstructural features of the material such as constituent phases their morphology, precipitates characteristics, nature of defects etc. Therefore, the microstructure is tailored as per the performance requirement by through controlled additions of alloying elements, thermo-mechanical- treatments. In order to obtain the desired microstructure, it is important to know the deformation behaviour of the material. Orientation dependent deformation behavior was studied in Zr using a combination of experimental and modeling (both discrete and atomistic dislocation dynamics) methods. Under the conditions of plane strain deformation, it was observed that single phase Zr, had significant extent of deformation heterogeneity based on local orientations. Discrete dislocation dynamics simulations incorporating multi slip systems had captured the orientation sensitive deformation. MD dislocations on the other hand brought the fundamental difference in various crystallographic orientations in determining the nucleating stress for the dislocations. The deformed structure has been characterized using X-ray, electron and neutron diffraction techniques. The various operating deformation mechanism will be discussed in this presentation. (author)

A Preliminary Model for Spacecraft Propulsion Performance Analysis Based on Nuclear Gain and Subsystem Mass-Power Balances

Science.gov (United States)

Chakrabarti, Suman; Schmidt, George R.; Thio, Y. C.; Hurst, Chantelle M.

1999-01-01

A preliminary model for spacecraft propulsion performance analysis based on nuclear gain and subsystem mass-power balances are presented in viewgraph form. For very fast missions with straight-line trajectories, it has been shown that mission trip time is proportional to the cube root of alpha. Analysis of spacecraft power systems via a power balance and examination of gain vs. mass-power ratio has shown: 1) A minimum gain is needed to have enough power for thruster and driver operation; and 2) Increases in gain result in decreases in overall mass-power ratio, which in turn leads to greater achievable accelerations. However, subsystem mass-power ratios and efficiencies are crucial: less efficient values for these can partially offset the effect of nuclear gain. Therefore, it is of interest to monitor the progress of gain-limited subsystem technologies and it is also possible that power-limited systems with sufficiently low alpha may be competitive for such ambitious missions. Topics include Space flight requirements; Spacecraft energy gain; Control theory for performance; Mission assumptions; Round trips: Time and distance; Trip times; Vehicle acceleration; and Minimizing trip times.

The current state and issues regarding communication from the nuclear energy industry to the mass media in Japan

International Nuclear Information System (INIS)

Tsuchida, Tatsuro; Kimura, Hiroshi

2011-01-01

The mass media has the potential to effect the utilization of nuclear power in Japan. In most cases journalists contact PR staff of the nuclear energy industry (hereinafter called 'the industry') to collect information about various events of nuclear energy. The industry is always ready to distribute related information and hold a press conference timely when necessary. In terms of the organizational structure for the PR activities each electric power company organizes the PR section in-house. The PR staff provides journalists with information on a daily basis. For the purpose of grasping the mass media's awareness, the author conducted interviews with 22 journalists who had experience in reporting news on nuclear energy subjects. The result showed that the journalists recognized the necessity of nuclear energy. The interviewees suggested that a proper press launch should be needed at just the right time especially in emergency situations and a press release should be more easily understandable. This interview showed that journalists considered the media reports as reflection of citizens' opinion. Most of the journalists realize that the influence of the media coverage should not be negligible and they acknowledge commutation between the two sides is gradually improved compared to before. (author)

Characterization of spent nuclear fuels by an online combination of chromatographic and mass spectrometric techniques

International Nuclear Information System (INIS)

Guenther-Leopold, Ines; Wernli, Beat; Kopajtic, Zlatko

2003-01-01

The determination of the burn-up is one of the essential parts in post-irradiation examinations on nuclear fuel samples. In the frame of national and international research programs the analysis of the isotopic vectors of uranium, plutonium, neodymium and some other fission products and actinides was carried out in the Hot lab of the Paul Scherrer Institute in the last years by using high-performance liquid chromatography coupled online with an inductively coupled plasma quadrupole mass spectrometer. In the meantime a multicollector ICP-MS, suitable for high precision isotope ratio measurements, was installed within the Hot lab and has been used now in combination with a chromatographic separation system for the first time for burn-up determinations of nuclear fuel samples. The results of these investigations, a comparison of both methods with the classical technique for burn-up analyses (thermal ionization mass spectrometry), the advantages and limitations of the methods and the accuracy and precision of this type of analyses are presented in the paper. (author)

Directions for nuclear research in the transplutonium elements

International Nuclear Information System (INIS)

Wilhelmy, J.B.; Chasman, R.R.; Friedman, A.M.; Ahmad, I.

1983-01-01

The study of the heavy nuclides has played a vital role in our understanding of the alpha decay process, nuclear fission, nuclear binding energies and the limits of nuclear stability. This study has led to the understanding of novel shape degrees of freedom, such as the very large quadrupole deformations associated with the fission isomer process, and the very recently discovered octupole deformation. The existence of these unique phenomena in the heavy element region is not accidental. Fission isomerism is due to the delicate balance between nuclear forces holding the nucleus together and Coulomb forces causing nuclear fission. Octupole deformation arises from the increasing strength of matrix elements with increasing oscillator shell. Both illustrate the unique features of the heavy element region. Fission studies have given us information about large collective aspects in nuclei and the importance that nuclear structural effects can play in altering these macro properties. A new class of atomic studies has become possible with the availability of heavy elements. With these isotopes, we are now able to produce electric fields of such magnitude that it becomes possible to spontaneously create positron-electron pairs in the vacuum. We have organized this presentation into three major sections: nuclear structure, fission studies and atomic studies of supercritical systems. In each we will try to emphasize the new directions which can benefit from the continued availability of isotopes supplied by the Trans-plutonium Production Program. 117 references

κ-Minkowski spacetime as the result of Jordanian twist deformation

International Nuclear Information System (INIS)

Borowiec, A.; Pachol, A.

2009-01-01

Two one-parameter families of twists providing κ-Minkowski * product deformed spacetime are considered: Abelian and Jordanian. We compare the derivation of quantum Minkowski space from two perspectives. The first one is the Hopf module algebra point of view, which is strictly related with Drinfeld's twisting tensor technique. The other one relies on an appropriate extension of ''deformed realizations'' of nondeformed Lorentz algebra by the quantum Minkowski algebra. This extension turns out to be de Sitter Lie algebra. We show the way both approaches are related. The second path allows us to calculate deformed dispersion relations for toy models ensuing from different twist parameters. In the Abelian case, one recovers κ-Poincare dispersion relations having numerous applications in doubly special relativity. Jordanian twists provide a new type of dispersion relations which in the minimal case (related to Weyl-Poincare algebra) takes an energy-dependent linear mass deformation form.

On the deformation twinning of Mg AZ31B

DEFF Research Database (Denmark)

Abdolvand, Hamidreza; Majkut, Marta; Oddershede, Jette

2015-01-01

and grain volumes are used to construct various 3D microstructures and model them with a Crystal Plasticity Finite Element (CPFE) code. It is observed that the average grain-resolved stress did not always select the highest ranked Schmid factor twin variant. In fact, the contribution of lower ranked......Crystals with a hexagonal close-packed (HCP) structure are inherently anisotropic, and have a limited number of independent slip systems, which leads to strong deformation textures and reduced formability in polycrystalline products. Tension along the c-axis of the crystal ideally activates......-ray diffraction (3DXRD) was used to map the center-of-mass positions, volumes, orientations, elastic strains, and stress tensors of over 1400 grains in-situ up to a true strain of 1.4%. More than 700 tensile twins were observed to form in the mapped volume under deformation. The measured center-of-mass positions...

Estimating the mechanical properties of the brittle deformation zones at Olkiluoto

International Nuclear Information System (INIS)

Hudson, J.A.; Cosgrove, J.W.; Johansson, E.

2008-09-01

In rock mechanics modelling to support repository design and safety assessment for the Olkiluoto site, it is necessary to obtain the relevant rock mechanics parameters, these being an essential pre-requisite for the modelling. The parameters include the rock stress state, the properties of the intact rock and the rock mass, and the properties of the brittle deformation zones which represent major discontinuities in the rock mass continuum. However, because of the size and irregularity of the brittle deformation zones, it is not easy to estimate their mechanical properties, i.e. their deformation and strength properties. Following Section 1 explaining the motivation for the work and the objective of the Report, in Sections 2 and 3, the types of fractures and brittle deformation zones that can be encountered are described with an indication of the mechanisms that lead to complex structures. The geology at Olkiluoto is then summarized in Section 4 within the context of this Report. The practical aspects of encountering the brittle deformation zones in outcrops, drillholes and excavations are described in Sections 5 and 6 with illustrative examples of drillhole core intersections in Section 7. The various theoretical, numerical and practical methods for estimating the mechanical properties of the brittle deformation zones are described in Section 8, together with a Table summarizing each method's advantages, disadvantages and utility in estimating the mechanical properties of the zones. We emphasise that the optimal approach to estimating the mechanical properties of the brittle deformation zones cannot be determined without a good knowledge, not only of each estimation method's capabilities and idiosyncrasies, but also of the structural geology background and the specific nature of the brittle deformation zones being characterized. Finally, in Section 9, a Table is presented outlining each method's applicability to the Olkiluoto site. A flowchart is included to

Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solutions

CERN Document Server

American Society for Testing and Materials. Philadelphia

1999-01-01

1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solution to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Determination of Uranium 7 Specific Gravity by Pycnometry 15-20 Free Acid by Oxalate Complexation 21-27 Determination of Thorium 28 Determination of Chromium 29 Determination of Molybdenum 30 Halogens Separation by Steam Distillation 31-35 Fluoride by Specific Ion Electrode 36-42 Halogen Distillate Analysis: Chloride, Bromide, and Iodide by Amperometric Microtitrimetry 43 Determination of Chloride and Bromide 44 Determination of Sulfur by X-Ray Fluorescence 45 Sulfate Sulfur by (Photometric) Turbidimetry 46 Phosphorus by the Molybdenum Blue (Photometric) Method 54-61 Silicon by the Molybdenum Blue (Photometric) Method 62-69 Carbon by Persulfate Oxidation-Acid Titrimetry 70 Conversion to U3O8 71-74 Boron by ...

The Characterization of Muria mountain deformation in the period of 2010-2104

International Nuclear Information System (INIS)

Ari Nugroho; Irwan Gumilar

2015-01-01

Deformation monitoring activity for Muria Mountain is recommended by the IAEA to be carried out in five years. The goal of this activity is to identify the soil deformation and strain surrounding Muria regionally and locally, this data is beneficial to support safety and reliability aspect of candidate site for constructing the Nuclear Power Plant in Muria Peninsula. Since the year of 2010 to 2014 the deformation monitoring had been applied in five benchmarks which are Mijen, Rahtawu, Perdopo, Cranggang, and Ketek Putih. The monitoring has been done successfully in collaboration with the faculty of Geodesy ITB. Based on the analysis by using GAMIT 10.4 it can be concluded that until the year of 2014 the regional deformation surrounding the Muria is dominated by plate movement namely Sunda block which has the acceleration as fast as 2.2 cm/year. The local deformation at the 5 Benchmark indicates the presence of deformation as fast as 2 - 3 mm/year. The strain measurement demonstrates the presence of the strain rate at Northern Muria as big as 2 x 10"-"2 microstrain/year, which is higher than the number of consistent strain (5 x 10"-"8 microstrain/year), this mean there is an indication of deformation. (author)

Nuclear mass formula with a neutron skin degree of freedom and finite-range model for the surface energy

International Nuclear Information System (INIS)

Moeller, P.; Myers, W.D.

1984-01-01

The possibility of extending the model used by Moeller and Nix in 1980 to calculate nuclear masses and fission barriers for nuclei throughout the periodic system to include provision for the existence of a neutron skin is studied. The model gives excellent fit to masses and fission barriers and improves predictions of isotopic trends in charge radii

Dynamic strain ageing of deformed nitrogen-alloyed AISI 316 stainless steels

International Nuclear Information System (INIS)

Ehrnsten, U.; Toivonen, A.; Ivanchenko, M.; Nevdacha, V.; Yagozinskyy, Y.; Haenninen, H.

2004-01-01

Intergranular stress corrosion cracking has occurred in BWR environment in non-sensitized, deformed austenitic stainless steel materials. The affecting parameters are so far not fully known, but deformation mechanisms may be decisive. The effect of deformation and nitrogen content on the behaviour of austenitic stainless steels was investigated. The materials were austenitic stainless steels of AISI 316L type with different amounts of nitrogen (0.03 - 0.18%) and they were mechanically deformed 0, 5 and 20%. The investigations are focused on the dynamic strain ageing (DSA) behaviour. A few crack growth rate measurements are performed on nuclear grade AISI 316NG material with different degrees of deformation (0, 5 and 20%). The effects of DSA on mechanical properties of these materials are evaluated based on peaks in ultimate tensile strength and strain hardening coefficient and minimum in ductility in the DSA temperature range. Additionally, internal friction measurements have been performed in the temperature range of -100 to 600 deg. C for determining nitrogen interactions with other alloying elements and dislocations (cold-worked samples). The results show an effect of nitrogen on the stainless steel behaviour, e.g. clear indications of dynamic strain ageing and changes in the internal friction peaks as a function of nitrogen content and amount of deformation. (authors)

Two phase transitions in Nuclear Physics

International Nuclear Information System (INIS)

Bes, D.R.

1985-01-01

The status of the art of the problem associated with two phase transitions in the nuclear matter, viz.: the disappearance of the nuclear superfluiditiy with the raising of the rotation velocity and the appearance of an octupolar deformation in the actinide zone, is presented. (L.C.) [pt

Nuclear spectroscopic studies. Progress report, June 1, 1983-May 31, 1984

International Nuclear Information System (INIS)

Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.

1984-01-01

Progress is reported on nuclear structure and nuclear reaction studies utilizing heavy-ion beams. Projects at the HHIRF, the Brookhaven Tandem Accelerator, and the Nuclear Science Facility at Daresbury, England are described. Studies have been concentrated on: (1) the structure of deformed and transitional nuclei in the angular momentum range from 20 to 40 h by (HI,xn) reactions; (2) the 1- and 2-nucleon transfer reactions between spherical heavy ion projectiles and deformed targets; and (3) the low-energy properties of nuclei far from stability. Theoretical studies are also reported. Publications are listed

On the questions of the nuclear level density and the E1 photon strength functions

International Nuclear Information System (INIS)

Mughabghab, S.F.; Dunford, C.L.

1999-01-01

New results were derived from average level spacings of neutron resonances for the spin dispersion parameter of the nuclear level density, which demonstrated the influence of shell effects, as well as the interplay of nucleon pairing correlations for nuclei in the mass range from 29 Si to 241 Pu. The volume and surface components of the nuclear level density parameter, as well as the shell-damping factor, were determined as, a v = 0.076 ± 0.009 MeV -1 , a s = 0.180 ± 0.047 MeV -1 , and y 0 = 0.047 ± 0.04 MeV±, respectively. The effective nucleon mass at the Fermi surface is derived as m*/m = 1.09 ± 0.13. New evidence is presented for a dipole-quadrupole interaction term in the primary E1 transitions of average resonance capture data. This evidence is obtained by testing a proposed generalized Landau Fermi liquid model for spherical and deformed nuclei, which includes the effect of the dipole-quadrupole interaction. The Landau-Migdal interaction constant and the effective nucleon mass, are determined as F 0 prime = 1.49 ± 0.08, and m*/m=1.04 ± 0.07, respectively

Role of shape and quadrupole deformation of parents in the cluster emission of rare earth nuclei

International Nuclear Information System (INIS)

Girija, K.K.; Joseph, Antony

2014-01-01

The nuclear structure effects on α decay and cluster emission are investigated in the case of even–even rare earth nuclei 150–160 Dy, 150–160 Er, 150–160 Yb, 158,162,166–176 Hf, 160,164–178 W and 162,166,170–180 Os. The role of shape and deformation of parent nuclei in the decay rate is studied by taking the Coulomb and proximity potentials as the interacting barrier for the post scission configuration. The quadrupole deformation of parent nuclei causes a slight change in the half-life of α emissions, but it affects the rate of heavy cluster emissions significantly. Prolate deformation of parents enhances cluster emission, while an oblate deformation slows down the decay. Shape and deformation of parent nuclei causes change in the branching ratio also. A prolate deformation increases the branching ratio, whereas an oblate deformation reduces it. Highest branching ratio is predicted at N ∼ 90. (author)

Nuclear chemistry research and spectroscopy with radioactive sources. Twentieth annual progress report, September 1, 1983-August 31, 1984

International Nuclear Information System (INIS)

Fink, R.W.

1984-01-01

Research under this continuing DOE contract centers on radioactive decay studies of nuclei far from stability produced with heavy ions from the Holifield Heavy Ion Research Facility (HHIRF) and studied on-line with the University Isotope Separator at Oak Ridge (UNISOR). These investigations encompass three aspects of nuclear structure research: nuclear spectroscopic measurements involving detailed γγt, γe - t, and Xγt three-parameter coincidence spectrometry; on-line laser hyperfine structure (hfs) and isotope shift spectroscopy for determining quadrupole moments, nuclear spins, and mean nuclear charge radii; and computer calculations of nuclear model predictions for comparison with the experimental level schemes. The focus of this research program is on odd-mass nuclei in which the odd nucleon probes the core, making possible observation of such phenomena as the onset of abrupt shape changes, the occurrence of shape coexistence, and shell-model intruder states. These phenomena are critical tests of concepts fundamental to an understanding of low-energy nuclear structure, such as nuclear deformations, shell models, collective models, and particle-core couplings

A stable partitioned FSI algorithm for incompressible flow and deforming beams

International Nuclear Information System (INIS)

Li, L.; Henshaw, W.D.; Banks, J.W.; Schwendeman, D.W.; Main, A.

2016-01-01

An added-mass partitioned (AMP) algorithm is described for solving fluid–structure interaction (FSI) problems coupling incompressible flows with thin elastic structures undergoing finite deformations. The new AMP scheme is fully second-order accurate and stable, without sub-time-step iterations, even for very light structures when added-mass effects are strong. The fluid, governed by the incompressible Navier–Stokes equations, is solved in velocity-pressure form using a fractional-step method; large deformations are treated with a mixed Eulerian-Lagrangian approach on deforming composite grids. The motion of the thin structure is governed by a generalized Euler–Bernoulli beam model, and these equations are solved in a Lagrangian frame using two approaches, one based on finite differences and the other on finite elements. The key AMP interface condition is a generalized Robin (mixed) condition on the fluid pressure. This condition, which is derived at a continuous level, has no adjustable parameters and is applied at the discrete level to couple the partitioned domain solvers. Special treatment of the AMP condition is required to couple the finite-element beam solver with the finite-difference-based fluid solver, and two coupling approaches are described. A normal-mode stability analysis is performed for a linearized model problem involving a beam separating two fluid domains, and it is shown that the AMP scheme is stable independent of the ratio of the mass of the fluid to that of the structure. A traditional partitioned (TP) scheme using a Dirichlet–Neumann coupling for the same model problem is shown to be unconditionally unstable if the added mass of the fluid is too large. A series of benchmark problems of increasing complexity are considered to illustrate the behavior of the AMP algorithm, and to compare the behavior with that of the TP scheme. The results of all these benchmark problems verify the stability and accuracy of the AMP scheme. Results for

A stable partitioned FSI algorithm for incompressible flow and deforming beams

Energy Technology Data Exchange (ETDEWEB)

Li, L., E-mail: lil19@rpi.edu [Department of Mathematical Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Henshaw, W.D., E-mail: henshw@rpi.edu [Department of Mathematical Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Banks, J.W., E-mail: banksj3@rpi.edu [Department of Mathematical Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Schwendeman, D.W., E-mail: schwed@rpi.edu [Department of Mathematical Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Main, A., E-mail: amain8511@gmail.com [Department of Civil and Environmental Engineering, Duke University, Durham, NC 27708 (United States)

2016-05-01

An added-mass partitioned (AMP) algorithm is described for solving fluid–structure interaction (FSI) problems coupling incompressible flows with thin elastic structures undergoing finite deformations. The new AMP scheme is fully second-order accurate and stable, without sub-time-step iterations, even for very light structures when added-mass effects are strong. The fluid, governed by the incompressible Navier–Stokes equations, is solved in velocity-pressure form using a fractional-step method; large deformations are treated with a mixed Eulerian-Lagrangian approach on deforming composite grids. The motion of the thin structure is governed by a generalized Euler–Bernoulli beam model, and these equations are solved in a Lagrangian frame using two approaches, one based on finite differences and the other on finite elements. The key AMP interface condition is a generalized Robin (mixed) condition on the fluid pressure. This condition, which is derived at a continuous level, has no adjustable parameters and is applied at the discrete level to couple the partitioned domain solvers. Special treatment of the AMP condition is required to couple the finite-element beam solver with the finite-difference-based fluid solver, and two coupling approaches are described. A normal-mode stability analysis is performed for a linearized model problem involving a beam separating two fluid domains, and it is shown that the AMP scheme is stable independent of the ratio of the mass of the fluid to that of the structure. A traditional partitioned (TP) scheme using a Dirichlet–Neumann coupling for the same model problem is shown to be unconditionally unstable if the added mass of the fluid is too large. A series of benchmark problems of increasing complexity are considered to illustrate the behavior of the AMP algorithm, and to compare the behavior with that of the TP scheme. The results of all these benchmark problems verify the stability and accuracy of the AMP scheme. Results for

Scientometric mapping of mass spectrometry research in nuclear science and technology: a global perspective. IT-8

International Nuclear Information System (INIS)

Sagar, Anil; Kademani, B.S.; Vijai Kumar

2007-01-01

This paper attempts to analyse quantitatively the growth and development of Mass Spectrometry research in Nuclear Science and Technology in terms of publication output as reflected in International Nuclear Information System (INIS) database (1970-2005). During 1970-2005, a total of 10913 papers were published in various domains: Chemistry, Materials and Earth Sciences (5286) (48.44%), Physical Sciences (2367) (21.69%), Engineering and Technology (1434) (13.14), Life and Environmental Sciences (1212) (11.11), other aspects of Nuclear and Non Nuclear Energy (492) (4.51%) and Isotopes, Isotope and Radiation Applications (122) (1.12%). There were only three papers published in 1970. The highest number of papers (816) were published in 2004. The average number of publications published per year was 303.13. United States topped the list with 2247 publications followed by Germany with 1333 publications, Japan with 820 publications, France with 525 publications, and India with 460 publications. Authorship and collaboration trend was towards multi-authored papers as 81.83 percent of the papers were collaborative is indicative of the multidisciplinary nature of research activity. The most prolific authors were: S.K. Aggarwal, Bhabha Atomic Research Centre, Mumbai, India with 113 publications, W. Kutschera, University of Vienna, Austria with 85 publications, and H.C. Jain, Bhabha Atomic Research Centre, Mumbai, India with 70 publications. The highly productive institutions were: Bhabha Atomic Research Centre, Mumbai (India) with 233 publications, Argonne National Laboratory (USA) with 150 publications, Oak Ridge National Laboratory (USA) with 146 publications, University of California (USA) with 118 publications, Los Alamos National Laboratory (USA) with 104 publications and Japan Atomic Energy Research Institute (Japan) with 91 publications. The journals most preferred by the scientists for publication of papers were: Nuclear Instruments and Methods in Physics Research

Direct mass measurements of {sup 100}Sn and magic nuclei near the N=Z line; Mesures directes des masses de {sup 100}Sn et de noyaux exotiques proches de la ligne N = Z

Energy Technology Data Exchange (ETDEWEB)

Chartier, M

1996-10-31

The masses of nuclei far from stability are of particular interest in nuclear structure studies, and many methods of varying precision have been developed to undertake their measurement. A direct time of flight technique in conjunction with the SPEG spectrometer at GANIL has been extended to the mass measurement of proton-rich nuclei near N = Z line in the mass region A {approx_equal} 60-80 known to provide input for astrophysical modelling of the rp-process and information relevant to the nuclear structure in a region of high deformation. The radioactive beams were produced via the fragmentation of a {sup 78}Kr beam on a {sup nat}Ni target, using the new SISSI device. A purification method based on the stripping of the secondary ions was successfully used for the first time, and the masses of {sup 70}Se and {sup 71}Se were measured. In order to improve the mass resolution for heavier nuclei, another method using the second cyclotron of GANIL (CSS2) as a high resolution spectrometer has been developed. An experiment aimed at measuring the masses of A 100 isobars in the vicinity of the doubly magic nucleus {sup 100}Sn was successfully performed, using this original technique. Secondary ions of {sup 100}Ag, {sup 100}Cd, {sup 100}In and {sup 100}Sn produced via fusion-evaporation reaction {sup 50}Cr + {sup 58}Ni and simultaneously accelerated in the CSS2 cyclotron. The mass of {sup 100}Cd and, for the first time, the masses of {sup 100}Sn were determined directly with respect to the reference mass of {sup 100}Ag. These results have been compared to various theoretical predictions and open the discussion on considerations of spin-isospin symmetry. (author). 96 refs.

Advertising campaigns on the necessity of nuclear energy through mass-media in Japan

International Nuclear Information System (INIS)

Niwano, Sadaji

1998-01-01

provide the public with materials and elements to think and decide with as information. In the background of those circumstances, the attitudes of PA activities toward the public-has changed recently to draw public attention to the wide range of issues from current severe energy conditions in Japan to global environmental problems connecting to the role and the position of nuclear power among overall national energy policies in Japan and let have urgent feelings among the public. Followings are the examples that we are taking up in promotion of advertising campaigns through mass media, including inter- net and other information tools. (1) To show concrete measures to be taken to meet national long- term energy supply/demand outlook for the year to 2030 that encourage energy- saving efforts, increased use of new energy sources and further development of nuclear power generation. (2) In this December, the 3rd Conference of the Parties to United Nations Framework Convention on Climate Change will be held at Kyoto, Japan. At this very moment that national attentions are increasingly concentrating toward the energy and environment issues, we will intend to hold advertising campaigns widely through mass media to heighten public awareness on the necessity of nuclear power promotion, as well as conservation and energy efficiency measures, introduction of alternative energy sources, such as solar, wind etc. in connection with the necessity of tackling the environmental problems, especially global warming phenomenon due to the greenhouse gas emissions. At this occasion, taking up some topics of specifically rapid energy demand which will obviously continue well into the next century and will very likely cause impending energy situations in Asian countries, expectations of serious environmental problems particularly in those of Asian countries, and among that appealing the role of nuclear energy as a clean energy source

The 1992 FRDM mass model and unstable nuclei

International Nuclear Information System (INIS)

Moeller, P.

1994-01-01

We discuss the reliability of a recent global nuclear-structure calculation in regions far from β stability. We focus on the results for nuclear masses, but also mention other results obtained in the nuclear-structure calculation, for example ground-state spins. We discuss what should be some minimal requirements of a nuclear mass model and study how the macroscopic-microscopic method and other nuclear mass models fullfil such basic requirements. We study in particular the reliability of nuclear mass models in regions of nuclei that were not considered in the determination of the model parameters

A study on the hierarchy model of nuclear reactions

International Nuclear Information System (INIS)

Kitazoe, Yasuhiro; Sekiya, Tamotsu

1975-01-01

The application of the hierarchy model of nuclear reaction is discussed, and the hierarchy model means that the compound nucleus state is formed after several steps, at least, one step of reaction. This model was applied to the analysis of the observed cross sections of 235 U and some other elements. Neglecting exchange scattering effect, the equations for the total neutron cross section of 235 U were obtained. One of these equations describes explicitly the hierarchy of the transition from intermediate reaction state Xm into the compound nucleus state Xs, and another one describes the cross section averaged over an energy interval larger than the average level spacing of compound nucleus eigenvalues. The hierarchy of reaction mechanism was investigated in more detail, and the hierarchy model was applied to the case of unresolved energy region. It was not tried to evaluate the strength function in the mass region (A>140), since the effect of nuclear deformation was neglected in the task. (Iwase, T.)

Deformed shell model studies of spectroscopic properties of Zn and ...

Indian Academy of Sciences (India)

2014-04-05

Apr 5, 2014 ... April 2014 physics pp. 757–767. Deformed shell model studies of ... experiments without isotopical enrichment thereby reducing the cost considerably. By taking a large mass of the sample because of its low cost, one can ...

Hydrogen-Induced Plastic Deformation in ZnO

Science.gov (United States)

Lukáč, F.; Čížek, J.; Vlček, M.; Procházka, I.; Anwand, W.; Brauer, G.; Traeger, F.; Rogalla, D.; Becker, H.-W.

In the present work hydrothermally grown ZnO single crystals covered with Pd over-layer were electrochemically loaded with hydrogen and the influence of hydrogen on ZnO micro structure was investigated by positron annihilation spectroscopy (PAS). Nuclear reaction analysis (NRA) was employed for determination of depth profile of hydrogen concentration in the sample. NRA measurements confirmed that a substantial amount of hydrogen was introduced into ZnO by electrochemical charging. The bulk hydrogen concentration in ZnO determined by NRA agrees well with the concentration estimated from the transported charge using the Faraday's law. Moreover, a subsurface region with enhanced hydrogen concentration was found in the loaded crystals. Slow positron implantation spectroscopy (SPIS) investigations of hydrogen-loaded crystal revealed enhanced concentration of defects in the subsurface region. This testifies hydrogen-induced plastic deformation of the loaded crystal. Absorbed hydrogen causes a significant lattice expansion. At low hydrogen concentrations this expansion is accommodated by elastic straining, but at higher concentrations hydrogen-induced stress exceeds the yield stress in ZnO and plastic deformation of the loaded crystal takes place. Enhanced hydrogen concentration detected in the subsurface region by NRA is, therefore, due to excess hydrogen trapped at open volume defects introduced by plastic deformation. Moreover, it was found that hydrogen-induced plastic deformation in the subsurface layer leads to typical surface modification: formation of hexagonal shape pyramids on the surface due to hydrogen-induced slip in the [0001] direction.

From chemical mapping to pressure temperature deformation micro-cartography: mineralogical evolution and mass transport in thermo-mechanic disequilibrium systems: application to meta-pelites and confinement nuclear waste materials; De l'imagerie chimique a la micro-cartographie Pression-Temperature-Deformation: evolution mineralogique et transport de matiere dans des systemes en desequilibre thermomecanique. Applications aux metapelites et aux materiaux de stockage de dechets radioactifs

Energy Technology Data Exchange (ETDEWEB)

Andrade, V. de

2006-03-15

The mineralogical composition of metamorphic rocks or industrial materials evolves when they are submitted to thermomechanical disequilibria, i.e. a spatial or temporal pressure and temperature evolution, or chemical disequilibria as variations in redox conditions, pH... For example, during low temperature metamorphic processes, rocks re-equilibrate only partially, and thus record locally thermodynamic equilibria increasing so the spatial chemical heterogeneities. Understanding the P-T evolution of such systems and deciphering modalities of their mineralogical transformation imply to recognize and characterize the size of these local 'paleo-equilibria', and so to have a spatial chemical information at least in 2 dimensions. In order to get this information, microprobe X-ray fluorescence maps have been used. Computer codes have been developed with Matlab to quantify these maps in view of thermo-barometric estimations. In this way, P-T maps of mineral crystallisation were produced using the multi-equilibria thermodynamic technique. Applications on two meta-pelites from the Sambagawa blue-schist belt (Japan) and from the Caledonian eclogitic zone in Spitsbergen, show that quantitative chemical maps are a powerful tool to retrieve the metamorphic history of rocks. From these chemical maps have been derived maps of P-T-time-redox-deformation that allow to characterize P-T conditions of minerals formation, and so, the P-T path of the sample, the oxidation state of iron in the chlorite phase. As a result, we underline the relation between deformation and crystallisation, and propose a relative chronology of minerals crystallisation and deformations. The Fe{sup 3+} content map in chlorite calculated by thermodynamic has also been validated by a {mu}-XANES mapping at the iron K-edge measured at the ESRF (ID24) using an innovative method. Another application relates to an experimental study of clay materials, main components of an analogical model of a nuclear

Calculation of ground state deformation of even-even rare-earth nuclei in sdg interacting boson model

International Nuclear Information System (INIS)

Wang Baolin

1995-01-01

The analytical calculation of the nuclear ground state deformation of the even-even isotopes in the rare-earth region is given by utilizing the intrinsic states of the sdg interacting boson model. It is compared systematically with the reported theoretical and experimental results. It is shown that the sdg interacting boson model is a reasonable scheme for the description of even-even nuclei deformation

Deformation-specific and deformation-invariant visual object recognition: pose vs identity recognition of people and deforming objects

Directory of Open Access Journals (Sweden)

Tristan J Webb

2014-04-01

Full Text Available When we see a human sitting down, standing up, or walking, we can recognise one of these poses independently of the individual, or we can recognise the individual person, independently of the pose. The same issues arise for deforming objects. For example, if we see a flag deformed by the wind, either blowing out or hanging languidly, we can usually recognise the flag, independently of its deformation; or we can recognise the deformation independently of the identity of the flag. We hypothesize that these types of recognition can be implemented by the primate visual system using temporo-spatial continuity as objects transform as a learning principle. In particular, we hypothesize that pose or deformation can be learned under conditions in which large numbers of different people are successively seen in the same pose, or objects in the same deformation. We also hypothesize that person-specific representations that are independent of pose, and object-specific representations that are independent of deformation and view, could be built, when individual people or objects are observed successively transforming from one pose or deformation and view to another. These hypotheses were tested in a simulation of the ventral visual system, VisNet, that uses temporal continuity, implemented in a synaptic learning rule with a short-term memory trace of previous neuronal activity, to learn invariant representations. It was found that depending on the statistics of the visual input, either pose-specific or deformation-specific representations could be built that were invariant with respect to individual and view; or that identity-specific representations could be built that were invariant with respect to pose or deformation and view. We propose that this is how pose-specific and pose-invariant, and deformation-specific and deformation-invariant, perceptual representations are built in the brain.

Inelastic scattering and deformation parameters

International Nuclear Information System (INIS)

Ford, J.L.C. Jr.

1978-01-01

In recent years there has been extensive study of nuclear shape parameters by electron scattering, μ meson atomic transitions, Coulomb excitation and direct nuclear inelastic scattering. Inelastic scattering of strongly absorbed particles, e.g., alpha-particles and heavy ions, at energies below and above the Coulomb barrier probe the charge and mass distributions within the nucleus. This paper summarizes measurements in this field performed at Oak Ridge National Laboratory

Accelerator-based ultrasensitive mass spectrometry

International Nuclear Information System (INIS)

Gove, H.E.

1985-01-01

This chapter describes a new mass spectrometry technique involving charged particle accelerators normally used for basic research in nuclear science. Topics considered include the limitations of conventional mass spectrometry, the limitations of the direct measurement of radioactive decay, mass spectrometry using a tandem electrostatic accelerator, mass spectrometry using a cyclotron, how accelerator mass spectrometry circumvents the limitations of conventional mass spectrometry, measurements of stable isotopes, nuclear physics and astrophysics applications, modifications to existing accelerators, descriptions of dedicated systems, and future applications

Large geometry secondary ion mass spectrometry (LG-SIMS) for the enhancement of nuclear safeguards applications

International Nuclear Information System (INIS)

Helberg, P.M.L.; Wallenius, M.; Vincent, C.; Albert, N.; Peres, P.; Truyens, J.

2013-01-01

A new LG-SIMS (Large Geometry Secondary Ion Mass Spectrometry) laboratory is currently being established at the Joint Research Centre, the Institute of Transuranium Elements for the purpose of improving the analytical capabilities within the European Commission. The laboratory will mainly be used for analysing uranium bearing aerosol particles collected on cotton swipes from nuclear Safeguards inspections but it will also be used for Nuclear Forensics and other Safeguards related applications. Until recently, this type of analysis has predominantly been performed using the small geometry CAMECA IMS 3F-7F instrument series. These instruments provide both particle screening and isotope ratio capabilities. The performance of these instruments was however limited by the occurrence of isobaric interferences, in particular for the minor isotopes ( 234 U, 236 U), that could not be resolved without compromising the transmission of the instrument. A recent breakthrough to solve this problem has been the implementation of Large Geometry SIMS, the CAMECA 1270 / 1280 / 1280-HR models, for this type of analysis. This instrument has originally been developed for geosciences applications requiring both high transmission and high mass resolution capabilities. This came out to be a key instrumental advantage also for uranium particle analyses, as it allows efficient removal of common molecular interferences with minimum loss in transmission. Furthermore an electrostatic ion optical device has been added for increasing the mass dispersion which allows the simultaneous detection of all uranium isotopes. The Automated Particle Measurement (APM) software has been developed to perform screening measurement in an automated mode. Combined with the APM screening software, LG-SIMS instruments greatly improve the overall performance and throughput of isotopic analyses of U particles for nuclear Safeguards purposes. The paper is followed by the slides of the presentation. (A.C.)

Rare-earth nuclei: Radii, isotope-shifts and deformation properties in the relativistic mean-field theory