In the framework of the EU fusion roadmap implementing activities, an accelerator-based Li(d,xn) neutron source called DONES (Demo-Oriented early NEutron Source) is being designed within the ...EUROfusion Work Package Early Neutron Source as an essential irradiation facility for testing candidate materials for DEMO reactor and future fusion power plants. DONES will employ a high speed liquid lithium jet struck by a 125 mA, 40 MeV deuteron beam to generate the intense neutron flux used to irradiate the material samples up to the desired level of displacement damage (˜10 dpa/fpy for iron in 0.3 l) and He production rates (˜10-13 appm He/dpa).
In order to rapidly achieve a sound and stable design, a new configuration of the DONES target system based on the so-called integral concept has been proposed as reference solution in place of the former baseline design that envisaged a target assembly endowed with a replaceable back-plate, being the latter solution not yet fully qualified and thus not readily implementable.
Moreover, following the outcomes of detailed dedicated analyses taking into account different aspects, the design of several components (Quench Tank, Lithium inlet pipe, Vacuum Chamber, etc.) has been changed.
In this paper, a brief description of the current design of the DONES Target System is presented including all the above-mentioned aspects, showing the capability of the system to fulfil the prescribed requirements.
•Thermo-hydraulic analysis of free surface Li flow over IFMIF Geometry is performed.•Minimum safety margins for lowest velocity (10m/s) and highest power at 30C.•Location of maximum temperature ...different from location of maximum pressure.•Inlet turbulence significantly effects the Li temperature distribution.•The Li free surface smooth, the jet thickens to 26.5mm at the center of the curvature.
A thermo-hydraulic analysis of high-speed free surface Li flow over a concave plate (IFMIF geometry) is performed. Simulations are done for bulk velocities between 10 and 20m/s using ANSYS Fluent. A pre-computed heat source was imposed at the center of the curved section to simulate the interaction of a dual deuteron beam with the Li jet. LES and k-ϵ models were used for turbulence modeling and Volume of Fluid and Level Set methods were used to model the free surface flow. Results reported are the variation of temperature, pressure and velocities across the Li jet at various locations along the curved region. Safety margins before Li starts boiling are also predicted. All cases predicted smooth surfaces without any waves.
The SORGENTINA-RF project aims to develop a 14 MeV fusion neutron source to produce medical radioisotopes with special focus on
99
Mo. The facility is based on a positive ion source with an ...acceleration stage to produce a deuterium (D
+
)
and tritium (T
+
)
ion beam that, impacting on a titanium-coated rotating target, allows fusion reactions to take place. Maximizing the neutron production rate is one of the main issues to be addressed in the project and the optimization of some key parameters of the ion beam is of paramount importance in this regard. In this study, a methodology is discussed to reach a definition of the beam characteristics for an effective and sustainable operation of the plant. The most convenient layout that has been found out is based on a single ion source fed by a deuterium and tritium gas mixture. Eventually, a series of considerations about the operation of the ion source and fuel cycle have been drawn.
A study devoted to assessing the neutronic performance of the SORGENTINA-RF fusion neutron source is here presented. The calculation is performed considering the characteristics of the accelerated ...mixed deuterium/tritium ion beam from the ion source, the transport of ions into the titanium layer that constitutes the ion beam target, their implantation and the fusion reaction cross section. An investigation has been done by varying the ion composition of the beam in order to assess if and to what extent diatomic and triatomic ion species affect the neutron emission rate of the plant. This calculation is also instrumental to evaluate the cost-effectiveness of equipping the ion source with a filtering system to remove secondary ions from the beam.
In the framework of fusion materials research, a neutron source has been considered a key installation to support EU plan toward DEMO reactor design. IFMIF facility being the present proposal, a ...pragmatic approach to EU fusion roadmap timeline considers complementary solutions mandatory, within a shared strategy. New Sorgentina Fusion Source (NSFS) has been recently proposed in order to populate an engineering database through materials irradiation tests. Proven technology of D–T neutron generators is implemented together with ion source and accelerator devices currently used in neutral injection systems at experimental tokamaks. Deuterium and tritium enriched hydride is on-line reloaded by impinging D–T beams via ion implantation onto a high-speed rotating target – D–T retention is allowed through temperature control. Hydride metal layer is re-deposited increasing plant availability factor. Target design is proposed to cope with thermal transients and mechanical loads. Solutions to thermal fatigue concerns are presented. Irradiation capability is then enhanced attaining relevant materials exposure. Main facility characteristics are provided as well as thermal and mechanical issues.
The SORGENTINA-RF fusion source will rely on a metallic, water cooled rotating target and an ion source that will deliver a mixed deuteron-tritium (50-50) beam featuring 300 keV energy and about 830 ...mA current. The ion source will be firstly tested in hydrogen, thus delivering a 300-keV/830-mA proton beam onto a beam dump, to assess the beam performance. This paper describes the interaction of the proton beam with the residual gas that will be in the drift tube of the accelerator. The study relies on analytical calculations, which describe the different processes in details, and Monte Carlo simulations performed using GEANT4. The physical processes involved are described in detail. Moreover, the analytical and numerical calculations provide some figures on the bremsstrahlung radiation field produced by the secondary electrons generated by means of the proton-gas interactions and accelerated by the extraction grids of the ion source.
The SORGENTINA-RF fusion source will rely on a metallic, water cooled rotating target and an ion source that will deliver a mixed deuteron-tritium (50-50) beam featuring 300 keV energy and about 830 ...mA current. The ion source will be firstly tested in hydrogen, thus delivering a 300-keV/830-mA proton beam onto a beam dump, to assess the beam performance. This paper describes the interaction of the proton beam with the residual gas that will be in the drift tube of the accelerator. The study relies on analytical calculations, which describe the different processes in details, and Monte Carlo simulations performed using GEANT4. The physical processes involved are described in detail. Moreover, the analytical and numerical calculations provide some figures on the bremsstrahlung radiation field produced by the secondary electrons generated by means of the proton-gas interactions and accelerated by the extraction grids of the ion source.
An analytical study, corroborated by Monte Carlo simulations, is presented which describes the interaction of a 300 keV–830 mA proton beam with a Cu and Al dumping system. The analytical ...calculations rely on the theoretical framework of the Particle Induced X-ray Emission, while the Monte Carlo simulations are performed by means of the GEANT4 toolkit. The case study is related to the project SORGENTINA-RF fusion neutron source and in particular to the tests devoted to assess the performance of the ion source of the plant. The results provide a detailed physical insight of the main processes occurring in the beam dump material, and are also important to give some realistic figures of the radiation emission expected during operation.
