A5034502712- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Plasma Diagnostics and Applications
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Particle Accelerators and Free-Electron Lasers
- Laser-Plasma Interactions and Diagnostics
- Atomic and Molecular Physics
- Fusion materials and technologies
- Nuclear Physics and Applications
- Laser-induced spectroscopy and plasma
- Solar and Space Plasma Dynamics
- Medical Imaging Techniques and Applications
- Advanced MRI Techniques and Applications
- Mechanical stress and fatigue analysis
- Advanced X-ray Imaging Techniques
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Fatigue and fracture mechanics
- Ultrasonics and Acoustic Wave Propagation
- Magnetic Field Sensors Techniques
- Radiation Therapy and Dosimetry
- Laser-Ablation Synthesis of Nanoparticles
- Structural Integrity and Reliability Analysis
- Gyrotron and Vacuum Electronics Research
Max Planck Institute for Plasma Physics
2015-2021
Max Planck Society
2015-2020
Institute of Plasma Physics
2018
National Agency for New Technologies, Energy and Sustainable Economic Development
2006-2016
University of Padua
2005-2015
Institute of Ionized Gas
2014-2015
Istituto Nazionale di Fisica Nucleare, Sezione di Padova
2006
The ITER neutral beam system will be equipped with radio-frequency (RF) negative ion sources, based on the IPP Garching prototype source design. Up to 100 kW at 1 MHz is coupled RF driver, out of which plasma expands into main chamber. Compared arc driven sources are maintenance free and without evaporation tungsten. modularity driver concept permits supply large volumes. (one driver) demonstrated operation in hydrogen deuterium up one hour relevant parameters. ELISE test facility operating...
The ITER project requires additional heating by two neutral beam injectors, each accelerating to 1 MV a 40 A of negative deuterium ions, deliver the plasma power about 17 MW for one hour. As these requirements have never been experimentally met, it was recognized as necessary setup test facility, PRIMA (Padova Research on Megavolt Accelerator), in Italy, including full-size ion source, SPIDER, and prototype whole injector, MITICA, aiming develop injectors be installed ITER. This realization...
Stable operation with control on magnetohydrodynamic modes has been obtained in the modified reversed field experiment employing a set of 192 feedback controlled saddle coils. Improvements plasma temperature, confinement (twofold), and pulse length (threefold) and, as consequence magnetic fluctuation reduction, strong mitigation plasma-wall interaction mode locking are reported.Received 27 January 2006DOI:https://doi.org/10.1103/PhysRevLett.97.075001©2006 American Physical Society
The RFX-mod machine (Sonato et al 2003 Fusion Eng. Des. 66 161) recently achieved, for the first time in a reversed-field pinch, high plasma current up to 1.6 MA with good confinement. Magnetic feedback control of magnetohydrodynamic instabilities was essential reach goal. As is raised, spontaneously accesses new helical state, starting from turbulent multi-helical conditions. Together this raise, ratio between dominant and secondary mode amplitudes increases continuous way. This brings...
The large-scale RF-driven ion source of the test facility extraction from a large experiment is aimed to deliver an accelerated current 20 A D− (23 H−) with extracted electron-to-ion ratio below one for up 1 h. Since first plasma pulses s in volume operation early 2013, followed by caesiation source, substantial progress has been achieved extending pulse length and RF power. record hydrogen are stable 400 18.3 at 180 kW total power 9.3 80 For deuterium pulse, limited amount co-extracted electrons.
RFX-mod is a reversed field pinch (RFP) experiment equipped with system that actively controls the magnetic boundary. In this paper we describe results of new control algorithm, clean mode (CMC), in which aliasing sideband harmonics generated by discrete saddle coils corrected real time. CMC operation leads to smoother (i.e. more axisymmetric) Tearing modes rotate (up 100 Hz) and partially unlock. Plasma–wall interaction diminishes due decrease non-axisymmetric shift plasma column. With...
With the exploration of MA plasma current regime in up to 0.5 s long discharges, RFX-mod has opened new and very promising perspectives for reversed field pinch (RFP) magnetic configuration, made significant progress understanding improving confinement controlling stability. A big leap with respect previous knowledge expectations on RFP physics performance been by since last 2006 IAEA Fusion Energy Conference. self-organized helical equilibrium experimentally achieved (the Single Helical...
The neutral beam heating system for the future international fusion experiment ITER will be based on radiofrequency driven ion sources delivering a large (≈1 × 2 m) and homogeneous negative hydrogen or deuterium of severals tens amperes up to 1 h. Such beams have never been produced before dedicated R&D process has ongoing more than two decades. An important intermediate step is size scaling test facility ELISE (Extraction from Large Ion Source Experiment) with its half-ITER source....
Abstract For the D-T operational phase of international fusion experiment ITER, starting in 2035, pulses are planned with Q > 10 and a duration 400 s = 5 for up to 3600 s. The two neutral beam injection (NBI) systems will deliver 33.3 MW heating power plasma also be an important source non-inductive current drive. An essential part NBI is large RF driven negative hydrogen or deuterium ions. In order fulfil requirements imposed system, ion has intense, stable homogeneous over pulse lengths...
Optimization of machine operation, including plasma position control, density control and especially feedback on multiple magnetohydrodynamic modes, has led RFX-mod to operate reliably at 1.5 MA, the highest current ever achieved a reversed field pinch (RFP). At high low magnetic topology spontaneously self-organizes in an Ohmical helical symmetry, with new axis helically twisting around geometrical torus. The separatrix island disappears leaving wide symmetric thermal structure large...
This paper reports the most recent experimental results on quasi-single helicity (QSH) reversed field pinch (RFP) plasmas. QSH is considered a key element towards full realization of theoretically predicted single (SH) RFP. The SH RFP, where an individual resistive kink mode and its harmonics drive dynamo electric field, to have superior confinement performance with respect standard multiple (MH) state. Magnetic chaos in fact strongly reduced which therefore retains all positive features RFP...
The reversed field pinch configuration is characterized by the presence of magnetic structures both in core and at edge: core, high plasma current spontaneous development a helical structure accompanied appearance internal electron transport barriers; edge strong pressure gradients, identifying an barrier, are observed too, related to position reversal surface.
RFX-mod [Sonato et al., Fusion Eng. Des. 66, 161 (2003)] exploits its 192 active coils in both reversed-field pinch (RFP) and tokamak configurations with varying degrees of 3D shaping, providing also a test bed for validating stellarator codes nonlinear magnetohydrodynamic codes. This makes unique flexible facility comparative studies on shaping control. The paper discusses how fields allow access to RFP advanced regimes. are used feedback control Single Helicity (SH) equilibria 1/7 helicity...
One of the main topics to be investigated at recently launched large (A(source) = 1.0 × 0.9 m(2)) ITER relevant RF driven negative ion test facility ELISE (Extraction from a Large Ion Source Experiment) is connection between homogeneity plasma parameters close extraction system and extracted hydrogen beam. While several diagnostics techniques are available for measuring beam homogeneity, determined by optical emission spectroscopy (OES) solely. First OES measurements show that without...
The ITER neutral beam system will be equipped with large radio frequency (RF) driven negative ion sources, a cross section of 0.9 m × 1.9 m, which have to deliver extracted D− beams 57 A at 1 MeV for h. On the extraction from source experiment test facility, half this size is being operational since 2013. goal demonstrate high reliability and achieve current densities properties required ITER. Technical improvements design RF were necessary provide reliable operation in steady state an power...
The modified RFX is a very flexible device used for variety of control schemes MHD instabilities and advanced reverse field pinch scenarios. Relative to the previous machine, RFX-mod has thin Cu shell with vertical penetration time τS, lowered from 450 50 ms shell/plasma proximity b/a = 1.24–1.1. Toroidal equilibrium feedback-controlled new power supplies provide better B control. Newly designed graphite tiles protect vessel localized deposition. A mesh 192 external saddle coils, supervised...
The full three-dimensional (3D) approach is now becoming an important issue for all magnetic confinement configurations. It a necessary condition the stellarator but also tokamak and reversed field pinch (RFP) cannot be completely described in axisymmetric framework. For RFP observation of self-sustained helical configurations with improved plasma performances require better description order to assess new view on this configuration. In framework configuration studies RFX-mod have been...
This paper summarizes the main achievements of RFX fusion science program in period between 2008 and 2010 IAEA Fusion Energy Conferences. RFX-mod is largest reversed field pinch world, equipped with a system 192 coils for active control MHD stability. The discovery understanding helical states electron internal transport barriers core temperature >1.5 keV significantly advances perspectives configuration. Optimized experiments plasma current up to 1.8 MA have been realized, confirming...
The study of electron temperature profiles quasi-single helical states (QSH) in RFX-Mod (and, general, other RFP machines) was carried out the past mainly using Thomson scattering, thus being limited to a time resolution order some milliseconds and collection single, isolated cases, which displayed clear transport barriers. A new multichord double filter SXR spectrometer developed installed. Temperature are now measured up frequency kHz, allowing one determine entire evolution during QSH...
Single Helical Axis (SHAx) configurations are emerging as the natural state for high current reversed field pinch (RFP) plasmas. These states feature presence of transport barriers in core plasma. Here we present a method computing equilibrium magnetic surfaces these force-free approximation, which has been implemented SHEq code. The is based on superposition zeroth order axisymmetric and first helical perturbation computed according to Newcomb's equation supplemented with edge measurements....
The transport of intrinsic and artificially introduced impurities is investigated in the multiple helicity (MH) quasi-single (QSH) plasma regimes RFX-mod reversed-field pinch. Impurities are through Ni laser blow-off Ne gas puffing both magnetic confinement scenarios. Simulation experimental spectroscopic measurements, including line soft x-ray emission, electron density radiated power carried out with a one-dimensional collisional–radiative model. For QSH MH an outwardly directed pinch...
A spontaneous transition to a helical equilibrium with an electron internal transport barrier is observed in RFX-mod as the plasma current raised above 1 MA (Lorenzini R et al 2009 Nature Phys. 5 570). The magnetic can be controlled external three-dimensional (3D) fields applied by 192 active coils, providing proper boundary conditions either rotating or static. persistence of strongly increased this way. slight reduction energy confinement time about 15% observed, likely due plasma–wall...