Experimental confirmation of efficient island divertor operation and successful neoclassical transport optimization in Wendelstein 7-X

We present recent highlights from the most recent operation phases of Wendelstein 7-X, the most advanced stellarator in the world. Stable detachment with good particle exhaust, low impurity content, and energy confinement times exceeding 100 ms, have been maintained for tens of seconds. Pellet fueling allows for plasma phases with reduced ion-temperature-gradient turbulence, and during such phases, the overall confinement is so good (energy confinement times often exceeding 200 ms) that the attained density and temperature profiles would not have been possible in less optimized devices, since they would have had neoclassical transport losses exceeding the heating applied in W7-X. This provides proof that the reduction of neoclassical transport through magnetic field optimization is successful. W7-X plasmas generally show good impurity screening and high plasma purity, but there is evidence of longer impurity confinement times during turbulence-suppressed phases.EC/H2020/633053/EU/Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium/ EUROfusio

Encapsulation of ISFET sensor chips

The encapsulation of ISFET sensor chips is a challenge to sensor technology and materials. Recently developed new packaging technologies enable reliable and cost effective chip encapsulation. By this, one of the serious problems, which had hindered the large-scale production and industrial application of ISFET sensors over three decades could be overcome now to a large extent. The paper reports both on ISFET encapsulation methods on laboratory level and advanced industrial production technologies. The influence of the packaging design on special applications and on the dynamic behaviour of the sensor is illustrated. Furthermore, sensor materials are characterised and various testing methods are described

Algebraic Multigrid for Discrete Elliptic Second Order Problems. February 1996

A Mixed Variational Formulation for 3D Magnetostatics and its Finite Element February 199