Search results for "CONFINEMENT"
showing 10 items of 213 documents
The power threshold of H-mode access in mixed hydrogen–tritium and pure tritium plasmas at JET with ITER-like wall
2022
The heating power to access the high confinement mode (H-mode), PLH, scales approximately inversely with the isotope mass of the main ion plasma species as found in (protonic) hydrogen, deuterium and tritium plasmas in many fusion facilities over the last decades. In first dedicated L–H transition experiments at the Joint European Torus (JET) tokamak facility with the ITER-like wall (ILW), the power threshold, PLH, was studied systematically in plasmas of pure tritium and hydrogen–tritium mixtures at a magnetic field of 1.8 T and a plasma current of 1.7 MA in order to assess whether this scaling still holds in a metallic wall device. The measured power thresholds, PLH, in Ohmically heated t…
Germanium Doped CHxMicroshells for LMJ Targets
2011
AbstractAt the CEA Laser “Megajoule” facility, amorphous hydrogenated carbon (a-C:H or CHx) is the nominal ablator used to achieve inertial confinement fusion experiments. These targets are filled with a fusible mixture of deuterium-tritium in order to perform ignition.Since the achievement of ignition greatly depends on the physical properties of the shell, there must be precise control of thicknesses, doping concentration, and roughness. Experimental devices associated with suitable characterizations are described in this paper. The tolerances and yields for each specification are also presented. Some specifications are largely reached; high-frequency surface roughness due to isolated sur…
A Model to Characterize the D-T Layer of ICF Targets by Backlit Optical Shadowgraphy
2005
A numerical model is presented in order to modelize the bright ring that appears in backlit optical shadowgraphy on a transparent hollow sphere with a solid deuterium-tritium layer inside. This novel model is based on computational calculations applied to the problem of the targets used in inertial confinement fusion. The model takes into account the influences of the optical imaging system (numerical aperture, source divergence, camera resolution, etc.) and the effect of the capsule itself, diameter, thickness, and refractive index, and allows one to analyze the inner surface of a capsule in terms of thickness and roughness.
Nature of the light scalar mesons
2005
Despite the apparent simplicity of meson spectroscopy, light scalar mesons cannot be accommodated in the usual $q\bar q$ structure. We study the description of the scalar mesons below 2 GeV in terms of the mixing of a chiral nonet of tetraquarks with conventional $q\bar q$ states. A strong diquark-antidiquark component is found for several states. The consideration of a glueball as dictated by quenched lattice QCD drives a coherent picture of the isoscalar mesons.
Glueball enhancement by color deconfinement
2007
5 pages, 4 figures.-- PACS nrs.: 14.80.-j; 24.80.+y; 25.75.Nq.-- ISI Article Identifier: 000245333000063.-- ArXiv pre-print available at: http://arxiv.org/abs/hep-ph/0609219
European Hadron Facility
1989
In this contribution we survey the physics potential of a facility such as EHF in somewhat general terms. In other words, we outline some fundamental questions in nuclear physics and low energy particle physics to whose advancement EHF can and will make substantial contributions, without going into specific experiments needed to answer them. It is the role of the case studies, presented in the EHF proposal(1), to illustrate the kind of experimental effort (typical beam requirements, characteristic detectors, size of experiments, etc.) needed at EHF for the physics one wishes to clarify.
Optimal design algorithm for seismic retrofitting of RC columns with steel jacketing technique
2020
Abstract Steel jacketing (SJ) of beams and columns is widely employed as retrofitting technique to provide additional deformation and strength capacity to existing reinforced concrete (RC) frame structures. The latter are many times designed without considering seismic loads, or present inadequate seismic detailing. The use of SJ is generally associated with non-negligible costs depending on the amount of structural work and non-structural manufacturing and materials. Moreover, this kind of intervention results in noticeable downtime for the building. This paper presents a new optimization framework which is aimed at obtaining minimization of retrofitting costs by optimizing the position an…
Espaces du quotidien et dynamiques de l’altérité pendant le confinement
2022
This study is the first result of the research entitled "Mon Espace Vécu" (My Lived Space) conducted in Italy during the first lockdown of 2020 (March-June), which was imposed by the government to contain the Covid-19 pandemic. During that period, the authors collected hundreds of textual testimonies from volunteers experiencing everyday spaces during the pandemic. The reflection, conducted from the perspective of cultural geography and cultural anthropology, develops from the analysis of some of these testimonies. Specifically, this paper focuses on the forms of semantization of space and the relationship between the body, space, and dynamic identity/otherness.
How to discover QCD Instantons at the LHC
2020
Topological Effects in the Standard Model: Instantons, Sphalerons and Beyond at LHC, Geneva, Switzerland, 16 Dec 2020 - 18 Dec 2020; The European physical journal / C 81(7), 624 (2021). doi:10.1140/epjc/s10052-021-09412-1
Complex permittivity of FeCl3/AOT/CCl4 microemulsions probed by AC impedance spectroscopy
2009
Abstract The complex permittivity of FeCl 3 /AOT/CCl 4 microemulsions in the 1–10 5 Hz frequency range has been measured by the conventional AC complex impedance technique. Measurements as a function of the volume fraction of the dispersed phase (FeCl 3 + AOT) and temperature at fixed salt-to-AOT molar ratio ( R , R = 0.5) show that the entrapment of FeCl 3 clusters significantly enhances the local permittivity of the AOT reverse micelles and the number density of charge carriers resulting from the peculiar state of the confined inorganic salt. An estimate of the apparent static permittivity of the FeCl 3 ionic clusters entrapped in the core of AOT reverse micelles gives the very high an…