Publications de Francesco Piras

Development of real-time plasma analysis and control algorithms for the TCV tokamak using SIMULINK

Olivier Sauter, Basil Duval, Stefano Coda, Timothy Goodman, Jean-Marc Moret, Federico Alberto Alfredo Felici, Wouter Vijvers, Alessandro Bortolon, James Paley, Lucia Isabel Federspiel

One of the key features of the new digital plasma control system installed on the TCV tokamak is the possibility to rapidly design, test and deploy real-time algorithms. With this flexibility the new control system has been used for a large number of new e ...

Elsevier2013

Extremely Shaped Plasmas to Improve the Tokamak Concept

Francesco Piras

Energy is essential for human existence and our future depends on plentiful and accessible sources of energy. The world population is fast growing and the average energy used per capita increases. One of the greatest challenges for human beings is that of ...

EPFL2011

Using APCS for Plasma Vertical Control at TCV

Basil Duval, Stefano Coda, Jean-Marc Moret, Federico Alberto Alfredo Felici, James Paley, Francesco Piras

Early tokamaks with circular cross-section plasmas were vertically stable in nature and no problems were reported on the control of the vertical position. However, the concept of vertically elongated plasma cross-section, with benefits to the energy confin ...

2011

Measurement of the magnetic field errors on TCV

Jean-Marc Moret, Francesco Piras, Jonathan Rossel

A set of 24 saddle loops is used on the Tokamak à Configuration Variable (TCV) to measure the radial magnetic flux at different toroidal and vertical positions. The new system is calibrated together with the standard magnetic diagnostics on TCV. Based on t ...

Fusion Engineering and Design2010

Experimental demonstration of an up-down asymmetry effect on intrinsic rotation in the TCV tokamak

Olivier Sauter, Basil Duval, Alexander Karpushov, Yann Camenen, Alessandro Bortolon, Lucia Isabel Federspiel, Francesco Piras

A new mechanism has recently been proposed that generates a radial flux of parallel momentum in toroidal plasmas. Namely, by considering up-down asymmetric flux surfaces, the symmetry following the magnetic field can be broken and an additional contributio ...

Institute of Physics2010

Experimental Evidence of Momentum Transport Induced by an Up-Down Asymmetric Magnetic Equilibrium in Toroidal Plasmas

Olivier Sauter, Basil Duval, Alexander Karpushov, Yann Camenen, Alessandro Bortolon, Lucia Isabel Federspiel, Francesco Piras

The first experimental evidence of parallel momentum transport generated by the up-down asymmetry of a toroidal plasma is reported. The experiments, conducted in the Tokamak a` Configuration Variable, were motivated by the recent theoretical discovery of i ...

2010

"Snowflake" H Mode in a Tokamak Plasma

Olivier Sauter, Basil Duval, Stefano Coda, Jean-Marc Moret, Benoît Labit, Francesco Piras, János Márki, Andreas Pitzschke

An edge-localized mode (ELM) H-mode regime, supported by electron cyclotron heating, has been successfully established in a snowflake (second-order null) divertor configuration for the first time in the TCV tokamak. This regime exhibits 2 to 3 times lowe ...

The American Physical Society2010

Snowflake divertor experiments on TCV

Olivier Sauter, Basil Duval, Stefano Coda, Jean-Marc Moret, Benoît Labit, Francesco Piras, János Márki, Andreas Pitzschke

An ELMy H-mode 'snowflake' (SF) divertor is established and studied for the first time in the TCV tokamak. The H-mode access and the edge localized mode (ELM) dynamics are compared with a conventional single-null diverted configuration. The SF configuratio ...

Institute of Physics2010

Real time control of plasmas and ECRH systems on TCV

Basil Duval, Stefano Coda, Timothy Goodman, Yves Martin, Jean-Marc Moret, Federico Alberto Alfredo Felici, James Paley, Francesco Piras

Developments in the real time control hardware on Tokamak à Configuration Variable (TCV) coupled with the flexibility of plasma shaping and electron cyclotron (EC) heating and current drive actuators are opening many opportunities to perform real time expe ...

IOP Publishing Ltd2009

Real time control of the sawtooth period using EC launchers

Stefano Coda, Timothy Goodman, Federico Alberto Alfredo Felici, James Paley, Francesco Piras

Tokamak plasmas operating at high performance are limited by several MHD instabilities. The sawtooth instability limits the core plasma pressure and can drive the neoclassical tearing mode unstable, but also prevents accumulation of impurities in the core. ...

Plasma Phys. Control. Fusion2009