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Nomenclatura Unesco > (22) Física > (2208) Nucleónica
(2208.01) Manipulación de haces (2208.02) Fuentes de haces
(2208.03) Reactores de fusión (2208.04) Núcleos
(2208.05) Aceleradores de partículas (2208.06) Detectores de partículas
(2208.07) Física de partículas (2208.08) Fuentes de partículas
(2208.09) Confinamiento de plasma (2208.99) Otras (especificar)

Mostrando recursos 1 - 20 de 396

1. Violación de paridad en dispersión elástica y cuasielástica de electrones por nucleones y núcleos - González Jiménez, Raúl
Los nucleones no son partículas puntuales, están constituidos por quarks que interaccionan entre sí mediante el intercambio de gluones. Los gluones pueden convertirse en pares quark-antiquark dando lugar al denominado mar de quarks. La Cromodinámica Cuántica (QCD) es la teoría fundamental que describe la interacción fuerte; sin embargo, debido a la complejidad de la dinámica quark-gluon, QCD no permite la obtención de resultados analíticos en la región de interés para la Física Nuclear a bajo cuadrimomento transferido, Q2. Alternativamente, la dinámica interna de los quarks dentro del nucleón puede ser descrita en términos de varias funciones fenomenológicas (factores de forma)...

2. Nuclear densities and the statistics of nucleonic constituents - Betz, Michel Emile Marcel; Hadjimichef, Dimiter
In the quark model of the nucleon, the Fermi statistics of the elementary constituents can in6uence significantly the properties of multinucleon bound systems. In the Skyrme model, on the other hand, the basic quanta are bosons, so that qualitatively different statistics effects can be expected a priori. In order to illustrate this point, we construct schematic one-dimensional quark and soliton models which yield fermionic nucleons with identical baryon densities. We then compare the baryon densities of a two-nucleon bound state in both models. Whereas in the quark model the Pauli principle for quarks leads to a depletion of the density...

3. Distribution of thorium nitrate between water and a mixture of butyl phosphate and butyl ether / - Anderson, Marion R.; Ames Laboratory.; U.S. Atomic Energy Commission. Technical Information Service.
An extraction system to remove the major portion of rare earths present in the commercial grade of thorium nitrate tetrahydrate available was found to be a necessary step in the production of thorium metal for nucleonic purposes. Distribution expressions were calculated and plotted, and equilibrium curves were plotted. Mention is also made of a number of methods of analysis which were attempted and proved unsatisfactory.

4. Palliser Rockslide cosmogenic 36Cl exposure ages (raw data) and erosion effect on the cosmogenic - Sturzenegger, Matthieu; Stead, Doug; Gosse, John; Ward, Brent; Froese, Corey
This paper presents the results of a combined study, using cosmogenic 36Cl exposure dating and terrestrial digital photogrammetry, of the Palliser Rockslide located in the southeastern Canadian Rocky Mountains. This site is particularly well-suited to demonstrate how this multi-disciplinary approach can be used to differentiate distinct rocksliding events, estimate their volume, and establish their chronology and recurrence interval. Observations suggest that rocksliding has been ongoing since the late Pleistocene deglaciation. Two major rockslide events have been dated at 10.0 ± 1.2 kyr and 7.7 ± 0.8 kyr before present, with failure volumes of 40 Mm3 and 8 Mm3, respectively. The...

5. Estudio del transporte de energía en plasma de fusión termonuclear con medidas experimentales obtenidas del espectrometro de intercambio de carga, realizado mediante técnicas de participación remota. - Fontdecaba Climent, Josep Maria
En la investigació de la fusió termonuclear controlada per confinament magnètic es important conèixer el transport d'energia en els plasmes, doncs aquest transport és el que fa que es refredi més o menys ràpidament amb el que s'obtindran o no les reaccions de fusió. El transport d'energia en els plasmes es majoritàriament turbulent o anòmal, fins la data no hi ha una teoria que expliqui satisfactòriament aquest tipus de transport, por tant per poder realitzar estudis i extrapolacions s'utilitzen models semiempírics en codis de simulació validats. Un d'aquests codis de simulació és PRETOR-Stellarator, utilitzat i millorat durant la realització d'aquesta...

6. Radiation Transport Modelling in a Tokomak Plasma: Application to Performance Prediciton and Design of Future Machines - Albajar Viñas, Ferran
The understanding and modelling of heat and radiation transport in tokamak plasmas is essential in order to progress in the development of thermonuclear fusion towards a practical energy source which meets all the future needs of environment, safety, and fuel inexhaustibility. This activity enables prospective studies and design to be carried out for next step tokamaks. Due to the complexity of the exact calculation, synchrotron losses are usually estimated in such studies, with expressions derived from a plasma description using simplifying assumptions on the geometry, radiation absorption, density and temperature profiles. In this thesis, a complete formulation of the transport...

7. Simulación de plasmas de dispositivos de fusión por confinamiento magnético tipo tokamak y stellarator. Validación experimental y aplicación al estudio del Heliac Flexible TJ-II - Fontanet Saez, Joan
En el estudio de la fusión por confinamiento magnético es crucial conocer con detalle las condiciones físicas del plasma confinado. En este sentido los códigos de simulación son una herramienta muy útil para interpretar las propiedades del plasma. A lo largo de esta tesis se ha estudiado las propiedades del plasma de tokamaks y stellarators y se ha contribuido al desarrollo del código de transporte PRETOR, creado en el JET. Estos estudios se han realizado dentro de la colaboración existente entre el DFEN de la UPC y el Laboratorio Nacional de Fusión del CIEMAT.El código PRETOR permite simular la variación...

8. The reaction D(γp)n at intermediate energies - Annand, J.R.M.; Anthony, I.; Crawford, G.I.; Dancer, S.N.; Hall, S.J.; Kellie, J.D.; McGeorge, J.C.; McPherson, A.; MacGregor, I.J.D.; Owens, R.O.; Wallace, P.; Schoch, B.; Vogt, J.; Beck, R.; Branford, D.; Springham, S.
Photodisintegration of the deuteron is an attractive reaction for detailed study since it is susceptible to calculation without approximations necessary in many body problems. The D-> np amplitude is sensitive to the nature of the NN interaction and to non-nucleonic components of the deuteron wavefunction. However, existing measurements of the cross section vary by 40% in the intermediate energy region. We intend to present results of a measurement of the differential cross se for the D(gaamma,p) reaction with an accuracy of +-4% over the energy range 80 to 130 MeV.

9. Deuteron Electro-Disintegration at Very High Missing Momenta - K. Aniol; F. Benmokhtar; W. U. Boeglin (spokesperson; P. E. Markowitz; B. A. Raue; J. Reinhold; M. Sargsian; M. Kohl; D. Gaskell; D. Higinbotham; M. K. Jones (co-spokesperson; G. Smith; S. Wood; S. Jeschonnek; J. W. Van Orden; G. Huber; E. Piasetzky; G. Ron; R. Shneor; H. Bitao; X. Jiang; A. Puckett; S. Danagoulian; H. Baghdasaryan; D. Day; N. Kalantarians; R. Subedi; F. R. Wesselmann; A. Asaturyan; A. Mkrtchyan; H. Mkrtchyan; V. Tadevosyan; S. Zhamkochyan
High-energy, exclusive electro-disintegration of the deuteron at missing momenta up to ≈ 1 GeV/c is considered as the most effective process to probe two nucleon dynamics at short space time distances. The latter condition is essential for probing the limits of nucleonic degrees of freedom in strong interaction dynamics. These are the distances at which the repulsive core of the strong interaction becomes dominant and a host of new dynamical effects such as the role of the non-nucleonic components and the transition from hadronic to quark-gluon degrees of freedom become increasingly important. 1.1 Importance of these studies for the field...

10. Exclusive Study of Deuteron Electrodisintegration near Threshold - G. D. Cates; R. Lindgren; N. Liyanage; V. Nelyubin; B. E. Norum; K. Paschke; L. C. Smith; R. Subedi; K. Wang; X. Zheng; W. Bertozzi; S. Gilad; B. Moffit; N. Sparveris; H. Arenhövel; M. Schwamb; B. Sawatzky; R. Igarashi; R. Pywell; G. Rosner; D. Watt; X. Jiang; J. Calarco; Y. Jiang; H. Lu; J. Shen; X. Yan; Y. Ye; Z. Yin; P. Zhu; J. P. Chen; J. -o. Hansen; D. W. Higinbotham; J. Lerose; V. Sulkosky
Elastic electron scattering from the deuteron and near-threshold electrodisintegration have long provided benchmarks against which models of the nucleon-nucleon interaction are evaluated. Recent measurements of T20 in elastic scattering have tightened the constraints but still leave room for ambiguity. We propose to make similar improvements in the constraints imposed by electrodisintegration with an exclusive study of the reaction d(e, e ′ p)n at Q 2 = 12 fm −2 and Enp = 2, 4, 6, 8 MeV. Under these kinematics, nonnucleonic as well as nucleonic degrees of freedom and relativistic effects are expected to play major roles. The experiment will...

11. Proposal to PAC-16 Hall A, Je erson Lab Isolation of SRC in the 3 He(e � e 0 pp)nsp Reaction Driven by One-Body Currents - K. Benslama; E. J. Brash; S. Dumalski; A. Fleck; G. M. Huber; N. Knecht; G. J. Lolos; K. Papageorgiou; Z. Pap; A. Shinozaki; K. Aniol; M. Epstein; D. Margaziotis; D. Meekins; R. Roche; A. J. Sarty; R. Gilman; C. Glasshauser; G. Kumbartzki; R. Ransome; S. Strauch; X. Xiang; M. Kuss; J. Templon; P. Ulmer
We propose a surgical measurement of short-range correlations (SRC), in inelastic electron scattering via the two proton knockout reaction 3He(e � e0pp)nsp. Such correlations have a speci c dynamical signature, in the ground state wavefunction of the target nucleus, which bridges the gap between nucleonic and quark degrees of freedom. As such, these measurements will provide severe constraints on existing theoretical models which employ realistic N-N potentials, while at the same time providing the impetus for new calculations. Our aim will be accomplished by separately measuring the longitudinal and transverse parts of the cross section, for the rst time, as...

12. Medium Modi cations of Vector Mesons in the Subthreshold Region Participants: - G. J. Lolos; Z. Pap; E. J. Brash; G. M. Huber; K. Benslama; S. Dumalski; A. Fleck; N. Knecht; A. Shinozaki; X. Chen; P. L. Cole; A. Larabee; F. J. Klein; S. G. Stepanyan; N. Bianchi; E. De Sanctis; M. Mirazita; V. Muccifora; F. Ronchetti; P. Rossi; M. Anghinol; M. Battaglieri; P. Corvisiero; M. Ripani; M. Taiuti; K. Sh. Egiyan; G. Gavalian; Y. G. Sharabian; B. Raue; R. Lewis; R. J. Van Der Meer; A. Afanasev
We propose to investigate the subthreshold photoproduction of the three lowest mass vector mesons, V = 0,!, and mesons. In the subthreshold energy region, de ned here as the energy region below the +N! V +N reaction threshold on the free nucleon, VMD-driven vector meson production is suppressed and the in uence of hadronic matter on the masses of the vector mesons is emphasized. This method is the optimum vehicle for the study of in-medium modi cations and, speci cally for the 0 meson, experimental evidence already exists for a dramatic reduction in m o, which is dependent on the...

13. Multifragmentation in Relativistic Heavy Ion Reactions - Trautmann Gesellschaft Fur; W. Trautmann
Multifragmentation is the dominant decay mode of heavy nuclear systems with excitation energies in the vicinity of their binding energies. It explores the partition space associated with the number of nucleonic constituents and it is characterized by a multiple production of nuclear fragments with intermediate mass. Reactions at relativistic bombarding energies, exceeding several hundreds of MeV per nucleon, have been found very efficient in creating such highly excited systems. Peripheral collisions of heavy symmetric systems or more central collisions of mass asymmetric systems produce spectator nuclei with properties indicating a high degree of equilibration. The observed decay patterns are well...

14. Atmospheric Chemistry and Physics The detection of solar proton produced 14 CO - P. Jöckel; C. A. M. Brenninkmeijer; M. G. Lawrence; P. Siegmund
Abstract. Major solar eruptions (coronal mass ejections) are accompanied by massive ejections of protons. When these charged particles head for the Earth through the interplanetary magnetic field with high flux and energy, a solar proton event (SPE) is recorded. Strong SPEs, in which energetic protons penetrate the atmosphere in large numbers are rare, but do have chemical effects (Crutzen, 1975; Jackman et al., 1990, 2001). They also have nucleonic effects by which they can almost instantaneously increase the atmospheric production of radio-nuclides, including 14 C (radiocarbon), but this has never been demonstrated. We show, using satellite observations and modeling, that...

15. Microwold 7. Electromagnetic Atomic Radiation Frequency Spectrum Mechanism - N. N. Leonov
The mechanism of electromagnetic atomic radiation frequency spectrum has been described. The mechanism of electromagnetic atomic radiation frequency spectrum can be identified if only there is detailed information on atomic structures available. Attempts to build adequate structural models of atoms made in the beginning of the previous century failed because of refusal to consider ether resistance to motion of microobjects and to consider magnetic interactions among atom elements the reason for which was a false conclusion that the material World lacks ether that would interact with microobjects and a false conclusion that magnetism is induce вин motion of electrical charges....

16. Adiabatic Decoupling and Time-Dependent Born-Oppenheimer Theory - Herbert Spohn; Stefan Teufel
We reconsider the time-dependent Born-Oppenheimer theory with the goal to carefully separate between the adiabatic decoupling of a given group of energy bands from their orthogonal subspace and the semiclassics within the energy bands. Band crossings are allowed and our results are local in the sense that they hold up to the first time when a band crossing is encountered. The adiabatic decoupling leads to a simple effective Schrödinger equation for the nuclei with a standard semiclassical limit. Since the local domain in the nucleonic configuration space is not required to be simply connected, the Berry connection has to be...

17. An Optimized Gamma-ray Densitometry Tool for Oil Products Determination - Amirmohammad Beigzadeh; Hossein Afarideh; Ar Asadi Amirabadi; Zahra Soltani; Gholam Reza Etaati
Copyright © 2013 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT: Gamma-ray densitometry or nucleonic gauges have been widely used in industries to improve the quality of products, optimize processes and save energy and materials. Compared with common time-consuming and expensive chemical analyses, the proposed method is relatively fast and more reliable. Density measurement is normally based on the absorption of gamma radiation as it passes through the process material. The absorption which is proportional...

18. ASTRONOMY AND ASTROPHYSICS On the origin of TeV radiation of SN 1006 - F. A. Aharonian; A. M. Atoyan
Abstract. We discuss the link between the nonthermal X-radiation and TeV γ-ray emission from SN 1006, and study the capabilities of both electronic and nucleonic models for explanation of the TeV flux observed from the northeast rim of SN 1006. We show that the interpretation of the TeV radiation by the inverse Compton scattering of electrons on 2.7 K cosmic microwave background radiation is possible, however due to the escape of high energy electrons, the γ-ray emission should be significantly contributed not only from the rim, but also from the inner parts of the remnant. This implies an angular size...

19. Properties of deformed Lambda hypernuclei - Zhou, X. R.; 周先荣
The properties of Be and B isotopes and the corresponding A hypernuclei are studied by using a deformed Skyrme Hartree-Fock approach with realistic nucleonic Skyrme forces, pairing correlations, and a microscopically determined lambda-nucleon interaction based on calculations of hupernuclear matter. The results suggest. that the core nuclei and die corresponding, hypernuclei have similar deformations with the same sign.

20. Nonrelativistic mean-field description of the deformation of I > hypernuclei - Zhou, X. R.; Cui, J. W.; Wei, N.; 周先荣
The deformations of light I > hypernuclei are studied in an extended nonrelativistic deformed Skyrme-Hartree-Fock approach with realistic modern nucleonic Skyrme forces, pairing correlations, and a microscopical lambda-nucleon interaction derived from Brueckner-Hartree-Fock calculations. Compared to the large effect of an additional I > particle on nuclear deformation in the light soft nuclei within relativistic mean field method, this effect is much smaller in the nonrelativistic mean-field approximation.

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