The Neutral Beam Injector (NBI) is required to inject in ITER plasma Deuteron particles which, once generated in the Ion Source (IS) polarized at -1MV, are accelerated at ground potential and then neutralized. This voltage level is very demanding for the power supply system, requiring several non-standard components. This paper describes the design status of two main NBI components: High Voltage Deck1 (HVD1) and the HVD1-TL Bushing. The former is a -1 MVdc air-insulated Faraday cage hosting the Ion Source and Extractor Power Supplies (ISEPS) and the associated diagnostics; the latter is a -1 MVdc feedthrough, interfaced with the SF6 insulated Transmission Line (TL) connecting the Acceleration Grid Power Supply system (AGPS) with the IS, carrying inside the ISEPS power conductors and diagnostics dedicated to the NBI Ion Source services. Both components are hosted inside a High Voltage Hall (HVH) with controlled environmental condition. The procurement started beginning 2015 and the manufacturing design will be finalized in the next months, aiming at testing the equipment in factory by end 2016. This paper presents the main design choices and the solutions adopted to comply with the challenging technical requirements. In particular, electrical field analysis has been carried out to verify the electrostatic design of components in final installation conditions inside the HVH, highlighting possible critical parts in surrounding elements (such as HVH irregularities and/or protrusions) that may require application of electrostatic screens, while mechanical analysis investigates the capability of the HVD1 structure and the HVD1-TL Bushing to withstand the seismic spectra foreseen at the installation sites. Moreover the thermal aspects concerning cooling down of the ISEPS components inside the HVD1 and of power conductors inside the HVD1-TL Bushing are described. Finally, next steps in terms of definition of special tests to verify some design choices will be also reported and discussed.
Final design of the HV deck1 and bushing for the ITER Neutral Beam Injector
Toigo V
2016
Abstract
The Neutral Beam Injector (NBI) is required to inject in ITER plasma Deuteron particles which, once generated in the Ion Source (IS) polarized at -1MV, are accelerated at ground potential and then neutralized. This voltage level is very demanding for the power supply system, requiring several non-standard components. This paper describes the design status of two main NBI components: High Voltage Deck1 (HVD1) and the HVD1-TL Bushing. The former is a -1 MVdc air-insulated Faraday cage hosting the Ion Source and Extractor Power Supplies (ISEPS) and the associated diagnostics; the latter is a -1 MVdc feedthrough, interfaced with the SF6 insulated Transmission Line (TL) connecting the Acceleration Grid Power Supply system (AGPS) with the IS, carrying inside the ISEPS power conductors and diagnostics dedicated to the NBI Ion Source services. Both components are hosted inside a High Voltage Hall (HVH) with controlled environmental condition. The procurement started beginning 2015 and the manufacturing design will be finalized in the next months, aiming at testing the equipment in factory by end 2016. This paper presents the main design choices and the solutions adopted to comply with the challenging technical requirements. In particular, electrical field analysis has been carried out to verify the electrostatic design of components in final installation conditions inside the HVH, highlighting possible critical parts in surrounding elements (such as HVH irregularities and/or protrusions) that may require application of electrostatic screens, while mechanical analysis investigates the capability of the HVD1 structure and the HVD1-TL Bushing to withstand the seismic spectra foreseen at the installation sites. Moreover the thermal aspects concerning cooling down of the ISEPS components inside the HVD1 and of power conductors inside the HVD1-TL Bushing are described. Finally, next steps in terms of definition of special tests to verify some design choices will be also reported and discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
