A5087811997- Particle accelerators and beam dynamics
- Magnetic confinement fusion research
- Plasma Diagnostics and Applications
- Particle Accelerators and Free-Electron Lasers
- Vacuum and Plasma Arcs
- Superconducting Materials and Applications
- Fusion materials and technologies
- Electrostatic Discharge in Electronics
- High voltage insulation and dielectric phenomena
- Atomic and Molecular Physics
- Metal and Thin Film Mechanics
- Magnetic Field Sensors Techniques
- Power Transformer Diagnostics and Insulation
- Advancements in PLL and VCO Technologies
- Advanced Frequency and Time Standards
- HVDC Systems and Fault Protection
- Nuclear Physics and Applications
- Network Time Synchronization Technologies
- Mass Spectrometry Techniques and Applications
- Gyrotron and Vacuum Electronics Research
- Silicon Carbide Semiconductor Technologies
- Ion-surface interactions and analysis
National Agency for New Technologies, Energy and Sustainable Economic Development
2017-2024
University of Padua
2018-2024
Institute for the Science and Technology of Plasmas
2022
Abstract The negative-ion based neutral beam injector for heating and current drive of the ITER plasma (ITER HNB) is under development, at present focusing on optimization full-scale source in SPIDER test stand. production H − or D ions ion low work function surfaces obtained by caesium evaporation. This paper describes conditioning procedure corresponding performances during first operation with caesium. Technical solutions to overcome limitations stand are described. influence parameters...
Heating neutral beam (HNB) injectors, necessary to achieve burning conditions and control plasma instabilities in ITER, are characterized by such demanding parameters that a test facility (NBTF) dedicated their development optimization is being realized Padua (Italy) with direct contributions from the Italian government (through Consorzio RFX as host entity) ITER international organization (with kind domestic agencies of Europe, Japan India) technical scientific support various European...
The requirements of ITER neutral beam injectors (1 MeV, 40 A negative deuterium ion current for 1 h) have never been simultaneously attained; therefore, a dedicated Neutral Beam Test Facility (NBTF) was set up at Consorzio RFX (Padova, Italy). NBTF includes two experiments: SPIDER (Source the Production Ions Deuterium Extracted from Rf plasma), full-scale prototype source injectors, with 100 keV accelerator, to investigate and optimize properties source; MITICA, entire injector, devoted...
Giant negative ion sources for neutral beam injectors deliver huge currents, thanks to their multi-beamlet configuration. As the single-beamlet optics defines transmission losses along beamline, extraction of a similar current all beamlets is extremely desirable, in order facilitate source operation (i.e., around perveance match). This Review investigates correlation between vertical profile intensity and profiles plasma properties at region source, focusing on influence increasing cesium...
An overview of the recent operations and main results cesium injection in Source for Production Ions Deuterium Extracted from Rf plasma (SPIDER) negative ion source are described this contribution. In experiments without injection, all SPIDER plants were tested to verify basic expectations on operational parameters (e.g., electron cooling effectiveness magnetic filter field) determine its region. For beam properties, it was shown that current density varies across vertical direction....
The Divertor Tokamak Test facility (DTT) will be a new experimental located at Frascati, Rome, Italy, whose main goal to have better understanding on hot plasma interactions with plasma-facing components (PFCs) and aid in the development of ITER successively DEMO. improved conceptual design beamline for DTT neutral beam heating (NBH) system is here overviewed, particular focus technical solutions adopted fulfill requirements maximize performances. proposed features providing deuterium...
Source for the production of ions deuterium extracted from a radio frequency plasma (SPIDER) is full-scale prototype ITER heating neutral beam (HNB) source. Beam operation in SPIDER, with eventual aim achieving 100-keV, 46-A hydrogen negative ion 1 h, has mainly been performed volume without cesium. Recently, introduction cesium, SPIDER moved to surface operational regime, noted increase current. Electrical and calorimetric measurements current have previously shown discrepancies between...
Study of High DC Voltage breakdown between stainless steel electrodes separated
SPIDER is the full scale prototype for ITER Heating Neutral Beam source, hosted at Test Facility in Padova, Italy. The behavior of beam must be thoroughly investigated to bring machine's performance line with ITER's requirements. In particular, ripples can affect its divergence. Measuring AC component current therefore help understand impact that oscillations caused by source power supplies or RF generators have on optics. To minimize occurrence electrical discharges, was recently operated a...
The ITER Heating Neutral Beam (HNB) source prototype SPIDER (Source for the Production of Ions Deuterium Extracted from a Radio frequency plasma), hosted at Test Facility (NBTF) in Padova, Italy, has recently started operating with evaporated caesium source. This moves primary H− production mechanism volume to surface processes, increasing extracted current while decreasing co-extracted electron current. As operation, beam exhibits inhomogeneities across vertical profile due magnetic drifts,...
For negative ion beam sources there are several methods of measuring the accelerated current, most commonly electrical measurements at power supply and calorimetric measurements. On SPIDER, ITER Heating Neutral Beam full-scale source prototype, acceleration grid (AGPS) complemented by polarizing diagnostic calorimeter STRIKE to provide an additional measurement current. This is in addition provided STRIKE. These diagnostics give differing Exploiting reduced number open apertures on SPIDER a...
In June 2018 the SPIDER device, which is full-size prototype of negative ion source and extractor for ITER Heating Neutral Beam has entered first operation phase at Test Facility (NBTF) in Padova, Italy. This paper describes present status experimental plans results obtained during campaign radio-frequency driven plasma source.
Event-driven data acquisition is used to capture information from fast transient phenomena typically requiring a high sampling speed. This an important requirement in the ITER Neutral Beam Test Facility for development of one heating systems nuclear fusion experiment. The Red Pitaya board has been chosen this project because its versatility and low cost. Versatility provided by hosted Zynq System on Chip (SoC), which allows full configuration module architecture OpenSource Pitaya. Price...
The electrical insulation of the Megavolt ITER Injector and Concept Advancement (MITICA) beam source (BS) at 1 MV in vacuum is a challenging issue, which could not be fully addressed so far on basis experimental results theoretical models available literature. A specific high-voltage (HV) test campaign being prepared to validate optimize voltage holding capability BS under realistic conditions, using full-size mockup electrodes reproducing detail geometry accelerator. proposed strategy will...
The ion source NIO1 (Negative Ion Optimization 1) was developed and installed as a reduced-size model of multi-aperture sources used in neutral beam injectors. optics is optimized for 135 mA H− current (subdivided 9 beamlets) at Vs = 60 kV extraction voltage, with an electron-to-ion ratio Rj up to 2. Depending on gas pressure used, now operated < 25 insulation tests. distinction between capacitively coupled plasma (E-mode, consistent low electron density ne) inductively (H-mode, requiring...
Counterintuitive experimental evidences have been observed during High Voltage Direct Current (HVDC) tests of two concave, axial-symmetric, electrodes insulated by large vacuum gaps 3 and 7 cm with voltages from 150 to 370 kVdc. The dissipation microdischarge power the conditioning procedure occurs mostly on anodic side in a region close axis system where electric field is at minimum, far positions breakdowns observed. analyses phenomena are carried out comparing temporal evolution voltages,...
Abstract Three years of experiments on SPIDER allowed characterization the main features source plasma and negative ion beam, in original design configuration. For large dimensions chamber, extraction area, investigation single-beamlet currents uniformity had to be carried out extend knowledge gained smaller prototype sources. The configuration multiple RF drivers filter field topologies were found cause a peculiar behavior confinement drivers, creating left-right asymmetries which also...
Megavolt ITER Injector and Concept Advancement (MITICA) is the full-size prototype of neutral beam injector (NBI) for currently under construction at test facility (NBTF) (Consorzio RFX, Padova, Italy). One main issues such a complex machine to secure stable voltage holding ion source-accelerator complex-which biased -1 MV constitutes very large (cathodic) area, with respect ground (the vessel). Coordinated experimental program HV facilities in Japan (QST, Naka) Italy (high Padova facility,...