Magnetic equilibrium design for the SMART tokamak

The SMall Aspect Ratio Tokamak (SMART) device is a new compact (plasma major radius R≥0.40 m, minor radius a≥0.20 m, aspect ratio A≥1.7) spherical tokamak, currently in development at the University of Seville. The SMART device has been designed to achieve a magnetic field at the plasma center of up to B=1.0 T with plasma currents up to I=500 kA and a pulse length up to τ=500 ms. A wide range of plasma shaping configurations are envisaged, including triangularities between −0.50≤δ≤0.50 and elongations of κ≤2.25. Control of plasma shaping is achieved through four axially variable poloidal field coils (PF), and four fixed divertor (Div) coils, nominally allowing operation in lower-single null, upper-single null and double-null configurations. This work examines phase 2 of the SMART device, presenting a baseline reference equilibrium and two highly-shaped triangular equilibria. The relevant PF and Div coil current waveforms are also presented. Equilibria are obtained via an axisymmetric Grad-Shafranov force balance solver (Fiesta), in combination with a circuit equation rigid current displacement model (RZIp) to obtain time-resolved vessel and plasma currents.The authors would like to thank the VEST team for their technical and engineering support. This work received funding from the Fondo Europeo de Desarollo Regional (FEDER) by the European Commission under grant agreement numbers IE17-5670 and US-15570. In addition support from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 805162) is gratefully acknowledged

Mechanical and electromagnetic design of the vacuum vessel of the SMART tokamak

The SMall Aspect Ratio Tokamak (SMART) is a new spherical device that is currently being designed at the University of Seville. SMART is a compact machine with a plasma major radius (R) greater than 0.4 m, plasma minor radius (a) greater than 0.2 m, an aspect ratio (A) over than 1.7 and an elongation (k) of more than 2. It will be equipped with 4 poloidal field coils, 4 divertor field coils, 12 toroidal field coils and a central solenoid. The heating system comprises of a Neutral Beam Injector (NBI) of 600 kW and an Electron Cyclotron Resonance Heating (ECRH) of 6 kW for pre-ionization. SMART has been designed for a plasma current (I) of 500 kA, a toroidal magnetic field (B) of 1 T and a pulse length of 500 ms preserving the compactness of the machine. The free boundary equilibrium solver code FIESTA [1] coupled to the linear time independent, rigid plasma model RZIP [2] has been used to calculate the target equilibria taking into account the physics goals, the required plasma parameters, vacuum vessel structures and power supply requirements. We present here the final design of the SMART vacuum vessel together with the Finite Element Model (FEM) analysis carried out to ensure that the tokamak vessel provides high quality vacuum and plasma performance withstanding the electromagnetic j×B loads caused by the interaction between the eddy currents induced in the vessel itself and the surrounding magnetic fields. A parametric model has been set up for the topological optimization of the vessel where the thickness of the wall has been locally adapted to the expected forces. An overview of the new machine is presented here.This work received funding from the Fondo Europeo de Desarollo Regional (FEDER) by the European Commission under grant agreement numbers IE17-5670 and US-15570. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 and 2019-2020 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission

Combinación de estrategias de innovación docente para la enseñanza de asignaturas de Ciencias de la Tierra: aprendizaje colaborativo y basado en proyectos como fuente de material para el aula invertida

Se han combinado diferentes estrategias de innovación docente para la creación de material de uso en el aula invertida. Grupos de alumnos han realizado micro-videotutoriales para la resolución de problemas básicos de cortes geológicos, realizando ellos mismos desde el guion hasta la edición, pasando por la grabación. Mediante esta actividad han tenido que desarrollar un proyecto y trabajar de forma colaborativa. El resultado de este trabajo ha sido una colección de microvideos que están siendo empleados en la formación de otros alumnos mediante el aula invertida en varias asignaturas de Ciencias de la Tierra. Los videos se han puesto a disposición de los alumnos a través de la plataforma Moodle de la UPM para que puedan aprender y repasar las técnicas de resolución de problemas de forma autónoma

Magnetic equilibrium design for the SMART tokamak

Article number 112706The SMall Aspect Ratio Tokamak (SMART) device is a new compact (plasma major radius Rgeo≥0.40 m, minor radius a≥0.20 m, aspect ratio A≥1.7) spherical tokamak, currently in development at the University of Seville. The SMART device has been designed to achieve a magnetic field at the plasma center of up to Bϕ=1.0 T with plasma currents up to Ip=500 kA and a pulse length up to τft=500 ms. A wide range of plasma shaping configurations are envisaged, including triangularities between −0.50≤δ≤0.50 and elongations of κ≤2.25. Control of plasma shaping is achieved through four axially variable poloidal field coils (PF), and four fixed divertor (Div) coils, nominally allowing operation in lower-single null, upper-single null and double-null configurations. This work examines phase 2 of the SMART device, presenting a baseline reference equilibrium and two highly-shaped triangular equilibria. The relevant PF and Div coil current waveforms are also presented. Equilibria are obtained via an axisymmetric Grad-Shafranov force balance solver (Fiesta), in combination with a circuit equation rigid current displacement model (RZIp) to obtain time-resolved vessel and plasma currents.Feder (UE) US-15570Feder (UE) IE17-5670Horizonte 2020 (Unión Europea) 80516

Student selection in a Brazilian university: using a multi-criteria method

La selección de estudiantes es un proceso de toma de decisiones complejo, en el que se deben considerar varios criterios simultáneamente. En este artículo, abordamos este problema para una universidad brasileña que ha creado un título interdisciplinario en el que se requieren varios procesos de selección intermedia durante el curso, definiendo el título final. Actualmente, la universidad está utilizando una puntuación agregada basada en el desempeño de un estudiante en el curso. Sin embargo, este método enfrenta dificultades para seleccionar a los mejores estudiantes, porque se tienen en cuenta las deficiencias en la forma en que se transfieren, abandonan y abandonan los créditos de los cursos. Como posible alternativa al método actual, desarrollamos un algoritmo de clasificación híbrido, llamado ELECTRE – TOPSIS (E – T). Este método combina elementos de la familia ELECTRE y TOPSIS, dos conocidas herramientas de análisis de atributos múltiples, clasificar a los estudiantes según criterios objetivos. Se llevaron a cabo experimentos computacionales y un estudio de caso para evaluar E – T. Los resultados muestran que nuestro enfoque proporciona clasificaciones bastante competitivas en comparación con métodos similares, al eliminar simultáneamente la inversión de clasificación y equilibrar mejor el tiempo de formación y el rendimiento académico de los estudiantes evaluados.Student selection is a complex decision-making process, in which several criteria need to be considered simultaneously. In this paper, we address this problem for a Brazilian university that has created an interdisciplinary degree in which several intermediate selection processes are required during the course, defining the final title degree. The university is currently using an aggregated score based on the performance of a student in the course. However, this method is facing difficulties in selecting the best students, because deficiencies in the way transferred, dropped and quit course credits are accounted for. As a possible alternative for the current method, we developed a hybrid ranking algorithm, called ELECTRE–TOPSIS (E–T). This method combines elements of the ELECTRE family and TOPSIS, two well-known multi-attribute analysis tools, to rank students based on objective criteria. Computational experiments and a case study were conducted to evaluate E–T. The results show that our approach provides quite competitive rankings in comparison with similar methods, through simultaneously eliminating ranking reversal and better balancing the formation time and the academic performance of the evaluated students