Showing 1 - 10 of 35 Journals Results
2021
UKAEA-CCFE-PR(21)04
M. Knolker T. Osborne E. Belli S. Henderson A. Kirk L. Kogan S. Saarelma P. B. Snyder
In preparation for the upcoming MAST-U campaign, pedestal stability of spherical tokamaks is revisited by investigating standard H-mode discharges on MAST. As a step beyond previous studies, both ion and electron profiles are used for obtaining equilibria and a diverse set of pedestals is evaluated. Stability analysis with the ELITE and CGYRO co…
Preprint2019
UKAEA-CCFE-PR(20)127
S. Saarelma L. Frassinetti P. Bilkova C.D. Challis A. Chankin R. Fridström L. Garzotti L. Horvath C.F. Maggi JET Contributors
The self-consistent core-pedestal prediction model of a combination of EPED1 type pedestal prediction and a simple stiff core transport model is able to predict type I ELMy pedestals of a large database JET-ILW (ITER-like wall) at the similar accuracy as is obtained when the experimental global plasma b is used as input. The neutral penetration …
Preprint Published2019
UKAEA-CCFE-PR(20)19
D. B. King E. Viezzer I. Balboa M. Baruzzo E. Belonohy J. Buchanan I.S. Carvalho K. Cave-Ayland I. Coffey C.D. Challis E.G. Delabie L. Garzotti S. Hall J.Hillesheim L. Horvath E. Joffrin D. Keeling K. Kirov C.F. Maggi M. Maslov S. Saarelma S. Silburn E.R. Solano M. Stamp D. Valcarcel H.Weisen
A study of mixed hydrogen-deuterium H-mode plasmas has been carried out in JET-ILW to strengthen the physics basis for extrapolations to JET D-T operation and to support the development of strategies for isotope ratio control in future experiments. Variations of input power, gas fuelling and isotopic mixture were performed in H-mode plasmas of the…
Preprint Published2019
UKAEA-CCFE-PR(19)62
L. Horvath C.F. Maggi A. Chankin S. Saarelma A.R. Field E. Belonohy A. Boboc G. Corrigan E.G. Delabie J. Flanagan L. Frassinetti C. Giroud D. Harting D. Keeling D. King M. Maslov G.F. Matthews S. Menmuir S.A. Silburn J. Simpson A.C.C Sips H. Weisen K.J. Gibson and JET Contributors
The pedestal structure, ELM losses and linear MHD stability are analysed in a series of JET-ILW H and D type I ELMy H-mode plasmas. The pedestal pressure (pPED) is typically higher in D than in H at the same input power, with the difference mainly due to lower density in H than in D. At the same input power, the pedestal electron pressur…
Preprint Purchase2019
UKAEA-CCFE-PR(19)59
J. P. Martin-Collar B. F. McMillan S. Saarelma A. Bottino
We perform a study of system-scale to gyro-radius scale electromagnetic modes in a pedestal-like equilibrium using a gyrokinetic code ORB5, and compare to the results of a local gyrokinetic code, GS2, and an MHD energy principle code, MISHKA. In the relevant large-system, short wavelength regime, good agreement between the gyrokinetic codes is foun…
Preprint Published2019
UKAEA-CCFE-PR(19)18
D A Ryan M Dunne A Kirk S Saarelma W Suttrop C Ham Y Q Liu M Willensdorfer the ASDEX Upgrade team the MST1 team
A numerical survey of the plasma response in ASDEX Upgrade ELM control experiments is conducted, to clarify the role of triangularity in the suppression mechanism. The pedestal pressure increases with triangularity consistent with previous work [2], which modestly boosts the peeling response. However, the peeling response decreases with increasi…
Preprint Published2018
UKAEA-CCFE-PR(18)3
L. Horvath C.F. Maggi F.J. Casson V. Parail L. Frassinetti F. Koechl S. Saarelma M.G. Dunne K.J. Gibson JET Contributors
Recent studies have shown that on JET with the Be/W ITER-like wall (JET-ILW) in high beta discharges with high D2 gas rates the inter-ELM temperature pedestal growth is saturated half way through the ELM cycle, leading to plasmas with reduced confinement, and that the linear MHD stability of these pedestals is inconsistent with the Peeling-Ballooni…
Preprint Published2017
CCFE-PR(17)74
L. Garzotti E. Barbato J. Garcia N. Hayashi G.Giruzzi P. Maget M. Romanelli S. Saarelma R. Stankiewitz M. Yoshida I. Voitsekhovitch R. Zagórski
Reference scenarios for the JT-60SA tokamak have been simulated with one-dimensional transport codes to assess the stationary state of the flat-top phase and provide a profile database for further physics studies (e.g. MHD stability, gyrokinetic analysis) and diagnostics design. The types of scenario considered vary from pulsed standard H-mode to a…
Preprint Published2017
CCFE-PR(17)13
S.Pamela G.Huijsmans T.Eich S.Saarelma I.Lupelli C.Maggi C.Giroud I.Chapman S.F.Smith L.Frassinetti M.Becoulet M.Hoelzl F.Orain S.Futatani JET Contributors
Future devices like JT-60SA, ITER and DEMO require quantitative predictions of pedestal density and temperature levels, as well as inter-ELM and ELM divertor heat fluxes, in order to improve global confinement capabilities while preventing divertor erosion/melting in the planning of future experiments. Such predictions can be obtained from dedicate…
Preprint Published2016
CCFE-PR(16)18