Contribution to fusion research from IAEA coordinated research projects and joint experiments

Abstract

The paper presents objectives and activities of IAEA Coordinated Research Projects 'Conceptual development of steady-state compact fusion neutron sources' and 'Utilisation of a network of small magnetic confinement fusion devices for mainstream fusion research'. The background and main projects of the CRP on FNS are described in detail, as this is a new activity at IAEA. Recent activities of the second CRP, which continues activities of previous CRPs, are overviewed.

NSTX-U theory, modeling and analysis results

“…New simulation and modeling capabilities have been developed to predict boundary turbulence, which influences particle and heat loads to divertor targets, and to predict operational limits of PFCs. The recent results in analysis, simulation and modeling of NSTX and NSTX-U, as well as future experiments on NSTX-U and other STs [154,[157][158][159], continue to advance the physics basis and technical solutions required for optimizing the configuration of next-step steady-state tokamak fusion devices.…”

Contribution of joint experiments on small tokamaks in the framework of IAEA coordinated research projects to mainstream fusion research

“…Experiments have been performed in shifts, and sometimes in parallel on two devices. Results were presented by the COMPASS and GOLEM teams jointly with the CRP team at many conferences and meetings, and comprehensively published [27][28][29][30][31][32][33][34][35][36][37][38], and references within. COMPASS, for the first time during JEs, implemented the neutral beam injection (NBI), which extended previous studies to new regimes with H-modes, the observation of fast particles and also was the first small tokamak to perform studies during JEs in the ITER-like divertor configuration.…”

“…Studies on the COMPASS tokamak during these JEs included characterization of the turbulent transport in limiter and divertor configurations; investigations of the plasma edge in the H-mode in the ohmic heated (OH) and the NB heated discharges, detailed studies of the plasma electric potential and of the electron energy distribution function (EEDF) at the plasma edge; the edge plasma studies using microwave emission; disruption studies and in particular the toroidal asymmetry [38]; studies of GAMs [34] and NBI-induced Alfvén Eigenmodes (AEs) [35] as well as AE studies in the ohmically heated discharges and studies in several other areas [31,32]. The width of the parallel heat flux in the scrape-off layer has been measured during the 6th JE on COMPASS, showing the decrease in the decay length with the increase in the plasma current or the average density [38] and effects of the 3D plasma distortion have been observed, increased during the pre-disruption phase.…”

“…During the JE6, studies of AEs on COMPASS tokamak have been performed in the plasma heated by the 40 keV neutral beam. However, AEs have also been observed in discharges when NBI was not used [31]. These modes were observed only in the H-mode phase of the discharge [50,51].…”

Adiabatic Compression of a Compact Torus

“…The development of compact fusion neutron sources for use in waste transmutation and fuel reprocessing has motivated an IAEA Coordinated Research Project (CRP) aiming for sources with P n =1-100MW (10 17 − 10 19 n/s) [1]. As part of this study a number of different candidates are being considered, based on the Tokamak, mirror, and spherical torus (ST).…”