Search results for "Toroid"
showing 10 items of 30 documents
Duality of moduli in regular toroidal metric spaces
2020
We generalize a result of Freedman and He [4, Theorem 2.5], concerning the duality of moduli and capacities in solid tori, to sufficiently regular metric spaces. This is a continuation of the work of the author and Rajala [12] on the corresponding duality in condensers. peerReviewed
Eurofusion-DEMO Divertor - Cassette Design and Integration
2020
International audience; The Eurofusion-DEMO design will complete the Pre Conceptual Design phase (PCD) with a PCD Gate, named G1, scheduled to take place in Q4 2020 that will focus on assessing the feasibility of the plant and its main components prior to entering into the Conceptual Design phase. In the paper first an overview is given of the Eurofusion-DEMO Divertor Assembly including design and interface description, systems and functional requirements, load specification, system classification, manufacturing procedures and cost estimate. Then critical issues are discussed and potential design solutions are proposed, e.g.:- Neutron material damage limits of the different (structural) mat…
The periods of the generalized Jacobian of a complex elliptic curve
2015
Abstract We show that the toroidal Lie group G = ℂ2/Λ, where Λ is the lattice generated by (1, 0), (0, 1) and (τ̂, τ͂), with τ̂ ∉ ℝ, is isomorphic to the generalized Jacobian JL of the complex elliptic curve C with modulus τ̂, defined by any divisor class L ≡ (M) + (N) of C fulfilling M − N = [℘ (τ͂) : ℘´(τ͂) : 1] ∈ C. This follows from an apparently new relation between the Weierstrass sigma and elliptic functions.
Transient Electrical Behaviour of the TF Superconducting Coils of Divertor Tokamak Test Facility During a Fast Discharge
2022
The paper is focused on the electromagnetic analysis of the Toroidal Field (TF) superconducting coils of the Divertor Tokamak Test facility (DTT) when electrical transients occur in the TF coils system: for example, during the operations of the Fast Discharge Units (FDUs) and considering also, the simultaneous occurrence of a fault condition. During the FDU intervention, a transient voltage excitation lasting few microseconds occurs at the TF coil terminals and it electrically stresses the insulations of TF coils itsef. To investigate the voltage distribution across, inside and between different Double Pancakes (DPs) of each TF coil, a lumped parameters circuital model has been developed an…
Non-linear evolutions of magnetized thick discs around black holes: dependence on the initial data
2020
We build equilibrium solutions of magnetised thick discs around a highly spinning Kerr black hole and evolve these initial data up to a final time of about 100 orbital periods. The numerical simulations reported in this paper solve the general relativistic magnetohydrodynamics equations using the BHAC code and are performed in axisymmetry. Our study assumes non-self-gravitating, polytropic, constant angular momentum discs endowed with a purely toroidal magnetic field. In order to build the initial data we consider three approaches, two of which incorporate the magnetic field in a self-consistent way and a third approach in which the magnetic field is included as a perturbation on to an othe…
Assessment of the Thermo-mechanical Performances of a DEMO Water-Cooled Liquid Metal Blanket Module
2015
Within the framework of DEMO R&D activities, a research cooperation has been launched between ENEA-Brasimone, CEA-Saclay and the University of Palermo to investigate the thermo-mechanical behaviour of the outboard equatorial module of the DEMO1 Water-Cooled Lithium Lead (WCLL) blanket, both under normal operation and over-pressurization steady state scenarios. The research campaign has been carried out following a theoretical-computational approach based on the finite element method (FEM) and adopting a qualified commercial FEM code. In particular, two different three-dimensional FEM models of the WCLL blanket module have been set-up to be used for normal operation and over-pressurization a…
Magnetized relativistic jets and helical magnetic fields
2021
This is the first of a series of two papers that deepen our understanding of the transversal structure and the properties of recollimation shocks of axisymmetric, relativistic, superfast magnetosonic, overpressured jets. They extend previous work that characterized these properties in connection with the dominant type of energy (internal, kinetic, or magnetic) in the jet to models with helical magnetic fields with larger magnetic pitch angles and force-free magnetic fields. In this paper, the magnetohydrodynamical models were computed following an approach that allows studying the structure of steady, axisymmetric, relativistic (magnetized) flows using one-dimensional time-dependent simulat…
From dots to doughnuts: Two-dimensionally confined deposition of polyelectrolytes on block copolymer templates
2016
© 2016 Elsevier Ltd The combination of block copolymer templating with electrostatic self-assembly provides a simple and robust method for creating nano-patterned polyelectrolyte multilayers over large areas. The deposition of the first polyelectrolyte layer provides important insights on the initial stages of multilayer buildup. Here, we focus on two-dimensionally confined “dots” patterns afforded by block copolymer films featuring hexagonally-packed cylinders that are oriented normal to the substrate. Rendering the cylinder caps positively charged enables the selective deposition of negatively charged polyelectrolytes on them under salt-free conditions. The initially formed polyelectrolyt…
Development of a Two-Dimensional Simplified Tool for the Analysis of the Cooling of the ITER TF Winding Pack
2018
The cooling of the ITER toroidal field (TF) coils winding pack is guaranteed by the circulation of supercritical helium (He) in seven hydraulic circuits corresponding to the Nb3Sn cable in conduit conductors, and in 74 channels devoted to the cooling of the stainless steel case supporting the winding pack. A tool entirely developed inside ANSYS with the APDL language has been created with the aim of computing the temperature distribution in the TF winding pack in different poloidal locations. The tool also allows the assessment of the He temperature during plasma operation in the case cooling channels. The considered heat load is the volumetric nuclear heating computed with the MCNP code in…
ISTTOK tokamak plasmas influence on a liquid gallium jet dynamic behavior
2011
Abstract The main concern in using free flowing liquid metals in fusion devices is related to their interaction with magnetic fields. On ISTTOK tokamak, liquid gallium jets are injected deep into the plasma along a vertical direction. The influence of the plasma interaction on the jet has been investigated monitoring the liquid metal behavior using a fast frame camera. A radial shift on its trajectory has been detected and found to depend on the toroidal magnetic field magnitude and principally on the plasma position within the chamber. The analysis performed to understand the dynamics of the jet perturbation by the plasma is presented in this paper. The jet surface temperature increase dur…