Neutral Beam Injectors (NBI) are fundamental to increase the plasma temperature in magnetic confinementfusion devices. In the perspective of dense and large plasmas foreseen in advanced experiments, the use ofnegative ions is needed to efficiently produce neutrals in MeV energy range, able to penetrate the plasmacore. In the framework of the accompanying activities in support to the ITER NBI test facility a relativelycompact radiofrequency (RF) ion source, named NIO1 (Negative Ion Optimization phase 1) is being developedand tested in Padua, Italy, in collaboration between Consorzio RFX and INFN. Negative hydrogen ions areformed in a cold, inductively coupled plasma with a 2MHz, 2.5 kW external antenna.The negative ions are extracted by means of a set of gridded electrodes to form 9 beamlets, arranged in a 3x3configuration. The nominal beam current is 135 mA and the final beam energy 60 keV. After the first test inAir and Argon doped Oxygen plasmas, the source is now routinely operated in Hydrogen, at an average RFpower <1200W. The set of diagnostic used include infra-red calorimetri, Langmuir probes, beam and sourcespectroscopy and linear CCD detectors. This contribution describes the main features of the experiment aswell as its current status. Future improvements to the extraction system are discussed.
Status of NIO1 negative ion source and acceleration system
Serianni Gianluigi;
2017
Abstract
Neutral Beam Injectors (NBI) are fundamental to increase the plasma temperature in magnetic confinementfusion devices. In the perspective of dense and large plasmas foreseen in advanced experiments, the use ofnegative ions is needed to efficiently produce neutrals in MeV energy range, able to penetrate the plasmacore. In the framework of the accompanying activities in support to the ITER NBI test facility a relativelycompact radiofrequency (RF) ion source, named NIO1 (Negative Ion Optimization phase 1) is being developedand tested in Padua, Italy, in collaboration between Consorzio RFX and INFN. Negative hydrogen ions areformed in a cold, inductively coupled plasma with a 2MHz, 2.5 kW external antenna.The negative ions are extracted by means of a set of gridded electrodes to form 9 beamlets, arranged in a 3x3configuration. The nominal beam current is 135 mA and the final beam energy 60 keV. After the first test inAir and Argon doped Oxygen plasmas, the source is now routinely operated in Hydrogen, at an average RFpower <1200W. The set of diagnostic used include infra-red calorimetri, Langmuir probes, beam and sourcespectroscopy and linear CCD detectors. This contribution describes the main features of the experiment aswell as its current status. Future improvements to the extraction system are discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
