Magnetoelectrostatic confinement in tandem mirror geometry

Summary Magnetoelectrostatic-confinement principles have been used to enhance the performance of a tandem mirror plasma device.

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Riassunto Si sono usati i principi di confinamento magnetoelettrostatico per migliorare la prestazione di un dispositivo a plasma dello specchio tandem.

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Резюме Используются принципы магнитозлектростатического удержания для улучшения характеристик плазменной установки со спаренными зеркалами.

     

Magnetic geometry and the confinement of electrically conducting plasmas

We develop an effective field theory approach to inspect the electromagnetic interactions in an electrically neutral plasma, with an equal number of negative and positive charge carriers. We argue that the static equilibrium configurations within the plasma are topologically stable solitons that describe knotted and linked flux tubes of helical magnetic fields.     

Influence of confinement geometry on ignition behavior of dust deposits

Effects of holding geometry on spontaneous combustible dust ignition are studied. Spontaneous ignition of coal dust deposited on a flat hot surface (1D case) and trapped between two hot surfaces (2D geometry), forming the shape of a wedge, is analyzed using lab-scale experiments and a mathematical model. The solution is obtained by assuming a temperature polynomial of third (one-dimensional) and fifth order (two-dimensional), in the energy conservation equation where the source term is defined using a 1-step Arrhenius type equation. The angle in wedge configuration is varied from 10° to 150° in steps of 10°. The results predicted by the mathematical model compare well with the trends shown by the experimental data. Consequent safety measures associated with dust layers trapped in corners or wedges are discussed.     

Self-assembly of lamella-forming diblock copolymers confined in nanochannels: Effect of confinement geometry

The self-assembly of symmetric diblock copolymers confined in the channels of variously shaped cross sections(regular triangles, squares, and ellipses) is investigated using a simulated annealing technique. In the bulk, the studied symmetric diblock copolymers form a lamellar structure with period LL. The geometry and surface property of the confining channels have a large effect on the self-assembled structures and the orientation of the lamellar structures. Stacked perpendicular lamellae with period LLare observed for neutral surfaces regardless of the channel shape and size, but each lamella is in the shape of the corresponding channel’s cross section. In the case of triangle-shaped cross sections, stacked parallel lamellae are the majority morphologies for weakly selective surfaces, while morphologies including a triangular-prism-shaped B-cylinder and multiple tridentate lamellae are obtained for strongly selective surfaces. In the cases of square-shaped and ellipse-shaped cross sections, concentric lamellae are the signature morphology for strongly selective surfaces, whereas for weakly selective surfaces, stacked parallel lamellae, and several types of folding lamellae are obtained in the case of square-shaped cross sections, and stacked parallel lamellae are the majority morphologies in the case of ellipse-shaped cross sections when the length of the minor axis is commensurate with the bulk lamellar period. The mean-square endto-end distance, the average contact number between different species and the surface concentration of the A-monomers are computed to elucidate the mechanisms of the formation of the different morphologies. It is found that the resulting morphology is a consequence of competition among the chain stretching, interfacial energy, and surface energy. Our results suggest that the self-assembled morphology and the orientation of lamellae can be manipulated by the shape, the size, and the surface property of the confining channels.     

No confinement without Coulomb confinement

We compare the physical potential V(D)(R) of an external quark-antiquark pair in the representation D of SU(N), to the color-Coulomb potential V(coul)(R) which is the instantaneous part of the 44-component: of the gluon propagator in Coulomb-gauge D44(x-->,t)=V(coul)(|x-->|)delta(t)+(noninstantaneous). We show that if V(D)(R) is confining, lim(V(D)(R)=+ infinity, as is believed to hold in the absence of dynamical quarks, then the inequality V(D)(R)0 is the Casimir in the representation D. This implies that -V(coul)(R) is also confining.     

Instantons and confinement

The Euclidean vacuum functional of Yang-Mills theory is saturated by infinitely large two-dimensional sheets of calculable universal thickness. The gauge fields inside the sheets are characterised by a distribution of instantons held together by a smooth solution of the field equations. The sheets cannot grow in the transverse directions. Within each sheet the orientation in group space of the average field is correlated to the spatial orientation of the area, while different sheets are totally uncorrelated. We exhibit a class of fluctuations above this background which confine quarks. No assumption about the infra-red behaviour of the Gell-Mann-Low function is used; all quantities are calculable and no free parameters exist beyond the group structure constants.     

Large-Nc confinement and turbulence

We suggest that the transition that occurs at large N_{c} in the eigenvalue distribution of a Wilson loop may have a turbulent origin. We arrived at this conclusion by studying the complex-valued inviscid Burgers-Hopf equation that corresponds to the Makeenko-Migdal loop equation, and we demonstrate the appearance of a shock in the spectral flow of the Wilson loop eigenvalues. This picture supplements that of the Durhuus-Olesen transition with a particular realization of disorder. The critical behavior at the formation of the shock allows us to infer exponents that have been measured recently in lattice simulations by Narayanan and Neuberger in d=2 and d=3. Our analysis leads us to speculate that the universal behavior observed in these lattice simulations might be a generic feature of confinement, also in d=4 Yang-Mills theory.     

Antimatter confinement

The magnetic-gradient accumulation ring is again proposed as a suitable apparatus for storing polarized atoms of anti-hydrogen at thermal energy.     

Quark confinement

Using renormalization group and field equation techniques and several smoothness assumptions, we argue the effective charge in an ultraviolet free SU(N) color gauge theory becomes infinite in the infrared limit if the number of quark flavors exceeds $\text{13N}\text{4}$.     

托卡马克高约束运行模式和磁约束受控核聚变

磁约束受控核聚变是最终解决人类能源问题的有希望的途径之一.托卡马克的高约束运行模式可以大大降低下一代磁约束聚变实验装置和将来的聚变示范反应堆的规模和造价.文章简要介绍了托卡马克高约束模式的特征,实现条件及亟待研究解决的科学技术问题,包括触发高约束模式的物理机理,功率阈值与等离子体参数的关系等,以及在高约束运行模式下观察到的边缘局域模的驱动机制、控制或缓解技术等.     

托卡马克高约束运行模式和磁约束受控核聚变

磁约束受控核聚变是最终解决人类能源问题的有希望的途径之一.托卡马克的高约束运行模式可以大大降低下一代磁约束聚变实验装置和将来的聚变示范反应堆的规模和造价.文章简要介绍了托卡马克高约束模式的特征,实现条件及亟待研究解决的科学技术问题,包括触发高约束模式的物理机理,功率阈值与等离子体参数的关系等,以及在高约束运行模式下观察到的边缘局域模的驱动机制、控制或缓解技术等.     

Conditions for confinement and freeze-out

Matter implies the existence of a large-scale connected cluster of a uniform nature. The appearance of such clusters as a function of hadron density is specified by percolation theory. We can therefore formulate the freeze-out of interacting hadronic matter in terms of the percolation of hadronic clusters. The resulting freeze-out condition as a function of temperature and baryo-chemical potential interpolates between resonance gas behavior at low baryon density and repulsive nucleonic matter at low temperature, and it agrees well with the data.Received: 10 September 2003, Published online: 7 November 2003     

Electric confinement and magnetic superconductors

Reinterpretation of the pioneering work of Nielsen and Olesen and others on magnetic confinement in (electric) superconductors leads to simple models which exhibit electric confinement of the type hoped for in quantum chromodynamics. “Electric” flux tubes joining “quarks” arise at a semi-classical level as a result of the existence of (pseudo) particles. The theory can be described in terms of a classical action principle only upon suitable modification of the action; this modification has profound topological significance as it is intimately related to the quantization condition for (pseudo) particles.     

BRS Transformation and color confinement

The condition of confinement of quarks and gluons in QCD is derived. It is shown that color confinement is realized when there exist massless scalar color-octet bound states of two Faddeev-Popov ghosts.     

Color effective particles and confinement

A brief review of works that are carried out in 2007–2009 and supported by the Russian Foundation for Basic Research, project no. 07-02-01197a, is presented. The idea is evolved that color confinement is realized by a singular interaction at large distances between color effective particles (constituent quarks, diquarks, and massive effective gluons).     

Supersymmetric strings and colour confinement

The (infinite-dimensional) supersymmetry algebra in 1 + 1 space-time dimension is extended in order to incorporate, in a non-trivial way, an internal symmetry. It turns out that this requirement implies that the internal symmetry is realized as a local gauge symmetry. Moreover, it is possible to construct string-like models with this underlying symmetry, where colour confinement is exactly realized as a consequence of the gauge constraints.     

Monopole condensation and color confinement

Monopole condensation is responsible for confinement in U(1) lattice gauge theory. Using numerical simulations and the abelian projection, we demonstrate that this mechanism persists in SU(2) nonabelian gauge theories. Our results support the picture of the QCD vacuum as a dual superconductor.     

Quark confinement and curved spaces

In this work it will be shown how quark confinement appears when wave equations derived in curved spaces are considered. First, the equations and their solutions for Coulomb-like potentials will be presented, and then, how this theory leads to quark confinement. A comparison between different models of confinement will also be made. Arrival of the final proofs: 6 December 2005     

Mapping gluonic excitations and confinement

One of the outstanding and fundamental questions in physics is the quantitative understanding of the confinement of quarks and gluons in quantum chromodynamics (QCD). Confinement is a unique feature of QCD. Exotic hybrid mesons manifest gluonic degrees of freedom and their spectroscopy will provide the crucial data needed to test assumptions in lattice QCD and phenomenology leading to confinement. Photoproduction is expected to be particularly effective in producing exotic hybrids but data using photon probes are sparse. At Jefferson Lab, plans are underway to use the coherent bremsstrahlung technique to produce a linearly polarized photon beam. A solenoid-based hermetic detector will be used to collect data on meson production and decays with statistics that will exceed the current photoproduction data in hand by several orders of magnitude after the first year of running. In order to reach the ideal photon energy of 9 GeV/c for this mapping of the exotic spectra, the energy of the Jefferson Lab electron accelerator, CEBAF, will be doubled from its current maximum of 6 GeV to 12 GeV. The physics and project are described.Received: 30 September 2002, Published online: 22 October 2003PACS: 12.39.Mk Glueball and nonstandard multi-quark/gluon states - 13.60.Le Meson productionA.R. Dzierba: Present address: Department of Physics, Indiana University, Bloomington, IN 47405 USA