Progress in the ITER neutral beam test facility

Abstract

Heating neutral beam (HNB) injectors, necessary to achieve burning conditions and to control plasma instabilities in ITER, are characterized by such demanding parameters that a neutral beam test facility (NBTF) dedicated to their development and optimization is being realized in Padua (Italy) with direct contributions from the Italian government (through Consorzio RFX as the host entity) and the ITER international organization (with kind contributions from the ITER domestic agencies of Europe, Japan and India) and technical and scientific support from various European laboratories and universities. The NBTF hosts two experiments: SPIDER, devoted to ion source optimization for the required source performance, and MITICA, the full-size prototype of the ITER HNB, with an ion source identical to SPIDER.This paper gives an overview of the progress towards NBTF realization, with particular emphasis on issues discovered during this phase of activity and on solutions adopted to minimize the impact on the schedule and maintain the goals of the facilities. The realization of MITICA is well advanced; operation is expected to start in 2023 due to the long procurement time of the in-vessel mechanical components. The beam source power supplies, operating at 1 MV, are in an advanced phase of realization; all high-voltage components have been installed and the complex insulation test phase began in 2018. At the same time, construction and installation of SPIDER plant systems was successfully completed with their integration into the facility. The mechanical components of the SPIDER ion source were installed inside the vessel and connected to the plants. Integrated commissioning with the control, protection and safety systems ended positively and the first experimental phase has begun. The first results of the SPIDER experiment, with data from operational diagnostics, and the plans for the 1 MV insulation tests on the MITICA high-voltage components are presented.

First operations with caesium of the negative ion source SPIDER

“…The radio-frequency (RF) driven source concept for ITER NBI was developed at IPP [3], reaching maturity with the half-ITER source ELISE [4,5]. The full-scale ion source prototype SPIDER (with a size of about about 1 × 2 m 2 and eight RF drivers) started the operation [6,7] at the ITER neutral beam test facility [8], as an intermediate step before MITICA, the full injector prototype for ITER.…”

NNBI for ITER: status of long pulses in deuterium at the test facilities BATMAN Upgrade and ELISE

“…Four RF generators (P RF up to 200 kW) are connected in series to two horizontally neighbouring drivers each. The test facilities SPIDER and MITICA of the neutral beam test facility in Padova, Italy, are using such ion sources [15]. SPIDER is in operation since 2018 while MITICA currently is under construction.…”

Progress toward ITER’s First Plasma

“…Research and development activities for the HNB will be carried out at a Neutral Beam Test Facility (PRIMA), where test beds of the ion source (SPIDER) and the full-scale injector (MITICA) will provide proof-of-concept testing for components designed for ITER [3]. The SPIDER test bed has begun routine operation of the beam source with the objective to demonstrate the ITER requirements.…”