Search results for "PLASMA"
showing 10 items of 4043 documents
Thermal-hydraulic study of the DEMO divertor cassette body cooling circuit equipped with a liner and two reflector plates
2021
Abstract In the framework of the Work Package DIV 1 – “Divertor Cassette Design and Integration” of the EUROfusion action, a research campaign has been jointly carried out by University of Palermo and ENEA to investigate the steady-state thermal-hydraulic performances of the DEMO divertor cassette cooling system. The research activity has been focussed onto the most recent design of the Cassette Body (CB) cooling circuit, consistent with the DEMO baseline 2017 and equipped with a liner and two Reflector Plates (RPs), whose main functions are to protect the underlying vacuum pump hole from the radiation arising from plasma and shield the PFCs inlet distributors, respectively. The research ca…
Thermal optimization of the Helium-Cooled Lithium Lead breeding zone layout design regarding TBR enhancement
2017
Abstract Within the framework of EUROfusion R&D activities, CEA-Saclay has carried out an investigation of the thermal and mechanical performances of alternative designs intended to enhance the Tritium Breeding Ratio (TBR) of the Helium-Cooled Lithium Lead (HCLL) Breeding Blanket (BB) for DEMO. Neutronic calculations performed on the 2014 DEMO HCLL baseline predicted a value of TBR equal to 1.07, lower than the required value of 1.1, necessary to ensure the tritium self-sufficiency of the breeding blanket taking into account uncertainties. In order to reach the TBR target, the strategy of the steel amount reduction inside the HCLL module breeding zone (BZ) has been followed by suppressing s…
On the effect of stiffening plates configuration on the DEMO Water Cooled Lithium Lead Breeding Blanket module thermo-mechanical behaviour
2019
Abstract Within the framework of the pre-conceptual design of the EU-DEMO Breeding Blanket (BB) supported by EUROfusion action, results of the research activities carried out in the last years have highlighted that changes in the proposed Water Cooled Lithium Lead (WCLL) BB design have to be considered, especially as to the liquid breeder circulation path within the BB module. Therefore, in view of the definition of a final WCLL BB module layout, a parametric campaign of numerical analyses has been carried out at the University of Palermo in order to assess the impact of different SPs configurations on the module thermo-mechanical performances. To this purpose, attention has been focussed o…
Start-up and shutdown thermomechanical transient analyses of the IFMIF European lithium target system
2014
In the framework of the current IFMIF Engineering Validation and Engineering Design Activities (IFMIF/EVEDA) phase, ENEA is responsible for the design of the European concept of the IFMIF lithium target system which foresees the possibility to periodically replace only the most irradiated and thus critical component (i.e., the backplate) while continuing to operate the rest of the target for a longer period (bayonet backplate concept). With the objective of evaluating the performances of the system in terms of temperature, stress and displacement fields evolution during start-up and shutdown phases, an uncoupled thermomechanical transient analysis has been performed in close collaboration w…
Safety analysis of the DONES primary heat removal system
2020
Abstract The development of a neutron source able to reproduce the irradiation conditions typical of a nuclear fusion reactor, in order to test candidate structural materials, is the main goal of the Work Package Early Neutron Source (WPENS) of the EUROfusion action. This source, named Demo Oriented NEutron Source (DONES), is a facility where neutrons are produced by means of D-Li interactions. More in detail, a beam of 125 mA deuterium ions at the energy of 40 MeV strikes a lithium jet flowing in a purposely shaped channel in order to obtain an intense and stable neutron flux for the irradiation of material samples. In the framework of these activities, safety analyses are a key aspect in …
Tracer-Encapsulated Solid Pellet (TESPEL) injection system for the TJ-II stellarator
2016
A tracer-encapsulated solid pellet (TESPEL) injection system for the TJ-II stellarator was recently developed. In order to reduce the time and cost for the development, we combined a TESPEL injector provided by National Institute for Fusion Science with an existing TJ-II cryogenic pellet injection system. Consequently, the TESPEL injection into the TJ-II plasma was successfully achieved, which was confirmed by several pellet diagnostics including a normal-incidence spectrometer for monitoring a tracer impurity behavior.
Thermal-hydraulic optimisation of the DEMO divertor cassette body cooling circuit equipped with a liner
2019
Abstract Within the framework of the Work Package DIV 1 - “Divertor Cassette Design and Integration” of the EUROfusion action, a research campaign has been jointly carried out by University of Palermo and ENEA to investigate the thermal-hydraulic performances of the DEMO divertor cassette cooling system. The research activity has been focused onto the most recent design of the Cassette Body (CB) cooling circuit equipped with a Liner, whose main function is to protect the underlying vacuum pump hole from the radiation arising from the plasma. The research campaign has been carried out following a theoretical-computational approach based on the Finite Volume Method and adopting the commercial…
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…
Investigation of ISIS and Brookhaven National Laboratory ion source electrodes after extended operation.
2012
Linac4 accelerator of Centre Européen de Recherches Nucléaires is under construction and a RFdriven H− ion source is being developed. The beam current requirement for Linac4 is very challenging: 80 mA must be provided. Cesiated plasma discharge ion sources such as Penning or magnetron sources are also potential candidates. Accelerator ion sources must achieve typical reliability figures of 95% and above. Investigating and understanding the underlying mechanisms involved with source failure or ageing is critical when selecting the ion source technology. Plasma discharge driven surface ion sources rely on molybdenum cathodes. Deformation of the cathode surfaces is visible after extended opera…
One-step synthesis and deposition of ZnFe2O4 related composite films via SPPS route for photodegradation application
2019
Binary spinel-type metal oxides (AB2O4) related materials, including ferrites (AFe2O4), are attractive photocatalysts thanks to their excellent visible light response for the photodegradation of organic pollutants. Currently, these materials are synthesized via conventional chemical routes suffering from long preparation duration and multistep. Moreover, the photocatalysts are obtained as nano-powders from conventional chemical routes would introduce another drawback for their recycling and reuse. From an industrial perspective, it is desirable to develop an efficient and facile synthesis process to produce photocatalysts in a non-dispersible form. Herein, we demonstrate that the solution p…