Effect of toroidal field ripple on plasma rotation in JET

Dedicated experiments on TF ripple effects on the performance of tokamak plasmas have been carried out at JET. The TF ripple was found to have a profound effect on the plasma rotation. The central Mach number, M, defined as the ratio of the rotation velocity and the thermal velocity, was found to drop as a function of TF ripple amplitude (3) from an average value of M = 0.40-0.55 for operations at the standard JET ripple of 6 = 0.08% to M = 0.25-0.40 for 6 = 0.5% and M = 0.1-0.3 for delta = 1%. TF ripple effects should be considered when estimating the plasma rotation in ITER. With standard co-current injection of neutral beam injection (NBI), plasmas were found to rotate in the co-current direction. However, for higher TF ripple amplitudes (delta similar to 1%) an area of counter rotation developed at the edge of the plasma, while the core kept its co-rotation. The edge counter rotation was found to depend, besides on the TF ripple amplitude, on the edge temperature. The observed reduction of toroidal plasma rotation with increasing TF ripple could partly be explained by TF ripple induced losses of energetic ions, injected by NBI. However, the calculated torque due to these losses was insufficient to explain the observed counter rotation and its scaling with edge parameters. It is suggested that additional TF ripple induced losses of thermal ions contribute to this effect

The ITER EC H&CD upper launcher: Methodology in the FEM analyses of the diamond window unit subject to seismic and baking loads

The ITER electron cyclotron upper launcher (EC UL) is used to direct high power microwave beams generated by the gyrotrons into the plasma for magneto-hydrodynamic (MHD) control and heating and current drive (H&CD) applications. The UL consists of an assembly of ex-vessel waveguides (WGs) and an in-vessel port plug. The diamond window units form vacuum and tritium confinement boundaries between the torus volume and the transmission lines (TLs) which guide beams between 1 and 2 MW from the gyrotrons to the launcher

Análise das tendências de pesquisa no Congresso de Agroinformática da Argentina: um estudo regional

Dado o aumento do volume de dados de diferentes tipos e origem, e a viabilidade de análise e tendências através de técnicas de Mineração de Dados, é possível se obter maior conhecimento sobre os dados armazenados e com isso visualizar um cenário atual do contexto que representam estes dados estruturados ou não estruturados. Com este conceito, desenvolve-se em paralelo o uso de tecnologia representada por nuvens de palavras, cuja finalidade é representar em uma figura, as palavras mais frequentes dentro de um documento. Com o objetivo de identificar quais as tendências das pesquisas do Congresso Argentino de Agroinformática (CAI), este trabalho faz uma abordagem nos dados referentes aos títulos dos artigos publicados neste evento no período entre 2008 a 2018, apontando as quais as Províncias da Argentina que mais publicaram e suas as respectivas tendências de pesquisa dos autores dentro deste Congresso.Sociedad Argentina de Informática e Investigación Operativ