O. Myatra D. Moulton B. Dudson S. Newton B. Lipschultz K. Verhaegh A. Fil
The role of ion-molecule elastic collisions (specifically D+−D2 collisions) in strongly detached divertor conditions has been studied in the MAST-U Super-X configuration using SOLPS-ITER. Two strongly detached steady state solutions, one obtained through a main-ion (D2) fuelling scan and the other through an impurity (N) seeding scan at fixed fue…
PreprintK. Verhaegh B. Lipschultz J.R. Harrison N. Osborne A. Williams P Ryan J. Allcock J. Clark F. Federici B. Kool T. Wijkamp A. Fil D. Moulton O. Myatra A. Thornton T.O.S.J. Bosman C. Bowman B. Duval S. Henderson R. Scannell the MAST Upgrade team the EuroFusion MST1 team
In this paper we a first qualitative analysis of the atomic and molecular processes at play during detachment in the MAST-U Super-X divertor, using divertor spectroscopy data. Our analysis indicates a wide operational regime of detachment of the MAST-U super-X divertor, which can be roughly separated in four phases: 1) The ionisation front detac…
PreprintA. Fil B. Lipschultz D. Moulton A. Thornton B. D. Dudson O. Myatra K. Verhaegh the EUROFusion WPTE team
MAST-U has recently started operating with a Super-X divertor, designed to increase total flux expansion and neutral trapping, both predicted through simple analytic models and SOLPS calculations to reduce the plasma and impurity density detachment thresholds. In this study, utilising the SOLPS-ITER code, we are quantifying the possible gain allowe…
Preprint PublishedK. Verhaegh B. Lipschultz J.R. Harrison B.P. Duval A. Fil D.S. Gahle D. Moulton O. Myatra A. Perek S. Henderson C. Theiler A. Thornton M. Wensing
This paper shows experimental results from the TCV tokamak that indicate plasma-molecule interactions involving D+2 and possibly D− play an important role as sinks of energy (through hydrogenic radiation as well as dissociation) and particles during divertor detachment if low target temperatures (< 3 eV) are achieved. Bot…
Preprint PublishedKevin Verhaegh Basil Duval Ben Dudson Alex Fil Olivier Février Daljeet Gahle James Harrison Omkar Myatra Artur Perek Christian Theiler Mirko Wensing
In this work we provide experimental insights into the impact of plasma-molecule interactions on divertor detachment by applying new spectroscopic analysis techniques to the hydrogen Balmer line series to investigate how both atom and plasma-molecule interactions impact particle balance. Our analysis on a representative L-mode TCV density ramp dis…
Preprint PurchaseK. Verhaegh B. Lipschultz C. Bowman B.P. Duval U. Fantz A. Fil D. Moulton O. Myatra D. Wünderlich F. Federici D.S. Gahle J.R. Harrison A. Perek M. Wensing
Detachment, an important mechanism for reducing target heat deposition, is achieved through reductions in power, particle and momentum; which are induced through plasma-atom and plasma-molecule interactions. Experimental research in how those reactions precisely contribute to detachment is limited. Both plasma-atom as well as plasma-molecule intera…
Preprint PublishedC. Bowman J. R. Harrison B. Lipschultz S. Orchard K. J. Gibson M. Carr K. Verhaegh O. Myatra
Advancing our understanding of divertor plasma physics is limited by an inability to directly determine the plasma characteristics (density, temperature, etc) over the entire divertor cross-section. At best, diagnostics are able to measure ne and Te at isolated points. More commonly however, diagnostics only measure higher-level quantities (e.g. em…
Preprint PublishedS.F. Smith S.J.P. Pamela A. Fil M. Hoelzl G.T.A. Huijsmans A. Kirk D. Moulton O. Myatra A.J. Thornton H.R. Wilson
ELM simulations for the MAST-U Super-X tokamak have been obtained, using the JOREK code. The JOREK visco-resistive MHD model has been used to obtain comparisons of divertor configurations. The simulations show a factor 10 decrease in the peak heat flux to the outer target of the Super-X in comparison to a conventional divertor configuration. A roll…
Preprint PublishedA. Fil B. Dudson B. Lipschultz D. Moulton O. Myatra K. Verhaegh O. Fevrier J. Harrison A. Thornton M. Wensing
Plasma detachment needs to be achieved in ITER [1] and future devices such as DEMO to dissipate most of the power in the Scrape-Off-Layer (SOL) and reduce the particle flux reaching the divertor targets. In order to enhance our capability to improve current, and design future tokamaks, we must improve our understanding of the relative effect on det…
Preprint PublishedA. Fil D. Moulton B. Dudson B. Lipschultz K. Verhaegh O. Février O. Myatra C. Theiler M. Wensing EUROfusion MST1 teams the TCV team
In ITER and DEMO, achieving detachment at lower densities would allow to reduce the amount of impurity seeded and to improve confinement by running at lower separatrix densities. Analytic models predict that a increase of total flux expansion would allow such a reduction in upstream density at detachment. However, both experiments and modelling …
Preprint Published