Effects of outer top gas injection on ICRF coupling in ASDEX Upgrade: towards modelling of ITER gas injection

Zhang, W.; Bobkov, V.; Noterdaeme, Jean-Marie; Tierens, W.; Bilato, R.; Carralero, D.; Coster, D.; Jacquot, J.; Jacquet, Philippe; Lunt, T.; Pitts, R.A.; Rohde, V.; Siegl, G.; Fuenfgelder, H.; Aguiam, D.; Silva, A.; Colas, L.; Ceccuzzi, S.

doi:10.1088/1361-6587/aa6fe5

Cited by 15 publications

(15 citation statements)

References 31 publications

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“…It is in contrast with the conventional expectation in ICRF that higher edge densities improve coupling-the basis for e.g. using gas puffing to improve coupling [50][51][52].…”

Section: Increasing Losses With Increasing Densitymentioning

confidence: 78%

On the origin of high harmonic fast wave edge losses in NSTX

et al. 2022

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“…It is in contrast with the conventional expectation in ICRF that higher edge densities improve coupling-the basis for e.g. using gas puffing to improve coupling [50][51][52].…”

Section: Increasing Losses With Increasing Densitymentioning

confidence: 78%

On the origin of high harmonic fast wave edge losses in NSTX

et al. 2022

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“…In what follows we will use 3D density data determined using EMC3-Eirene for the "Mid-3" gas-puffing case in ASDEX Upgrade [13]. Let us call this n Mid3 (R, θ, z).…”

Section: Comparison Between Simulation Results With 1d and 3d Densitymentioning

confidence: 99%

3-Dimensional density profiles in edge plasma simulations for ICRF heating

et al. 2017

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Abstract. In this paper we discuss improvements made to two codes for the simulation of ICRF waves in edge plasmas: SSWICH-SW, which self-consistently models the interplay between sheath physics and radiofrequency waves (the slow wave), and RAPLICASOL, a Finite Element solver for Maxwell's equations in the cold plasma approximation. We have extended both to be able to handle 3D plasma density profiles. A comparison between a 1D and a 3D simulation reveals that the density profile dimensionality has a relatively small effect on E at the aperture, but a large effect on the sheath potential at the antenna limiters

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“…The ICRF coupling issue can be well solved by puffing fueling gas locally close to the ICRF antenna. Previous experiments and simulations on ASDEX Upgrade (AUG) [16,17], JET [18,19] and ITER-relevant scenarios [20] indicate that compared to lower divertor gas puffing, midplane gas puffing close to the antenna increases the antenna coupling resistance to more than double (by ~120%) and top gas puffing increases this value by ~20%-40%. No plasma confinement degradation is found when shifting the gas source from the divertor to the top or midplane of the main chamber [18,19].…”

Section: Emc3-eirene Modeling Of Edge Plasma To Improve the Icrf Coup...mentioning

confidence: 99%

“…Within one sector, the localized gas source is the only 3D feature of the simulation. In contrast, grids with a toroidal extension of 360° had to be used in AUG and JET simulations [17,18,20] because in these machines only one or two local gas valves are used simultaneously and the resulting densities are rather toroidal inhomogenous in a large toroidal extent. The toroidal boundary of the simulation grid is defined as follows: the plasma exiting one toroidal boundary is considered entering the simulated region from the other side.…”

Section: Simulation Configurationsmentioning

confidence: 99%

EMC3-EIRENE modeling of edge plasma to improve the ICRF coupling with local gas puffing in DEMO

et al. 2018

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We report the first 3D EMC3-EIRENE simulations of scrape-off layer (SOL) plasma in DEMO. EMC3-EIRENE is a 3D edge plasma fluid and neutral particle transport code. Effects of local gas puffing on the SOL density and Ion Cyclotron Range of Frequencies (ICRF) power coupling have been studied. A pure deuterium is simulated and the puffing/fueling gas is deuterium gas. The investigated gas puffing cases include the divertor, top, midplane and antenna gas puffing. The ICRF antenna is toroidally 360 o distributed and poloidally located in the outer top of the vessel. The results show that toroidal distributed but poloidal localized antenna gas puffing increases the density in front of the antenna most significantly while top or midplane gas puffing increases this antenna density to a moderate level. Influences of gas puff rate and particle transport parameters on the SOL density are investigated. The parameter scans indicate that the shift of the fast wave cutoff density position to the antenna depends almost linearly on the total gas puff rate. To achieve a significant antenna density increase, the antenna gas puff rate should be at the level of 1.8 × 10 23 el/s (i.e. 1.0 × 10 22 el/s per tokamak segment). As the total gas puff rate increases to 4.0 × 10 23 el/s, the evanescent layer of the fast wave (with k || = 2 m-1) almost vanishes. Moreover, it is found that antenna gas puffing reduces the local power flux to the main chamber wall near the gas valve due to a local decrease of the SOL temperature.

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Effects of outer top gas injection on ICRF coupling in ASDEX Upgrade: towards modelling of ITER gas injection

Cited by 15 publications

References 31 publications

On the origin of high harmonic fast wave edge losses in NSTX

On the origin of high harmonic fast wave edge losses in NSTX

3-Dimensional density profiles in edge plasma simulations for ICRF heating

EMC3-EIRENE modeling of edge plasma to improve the ICRF coupling with local gas puffing in DEMO

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