A review of the dimensionless parameter scaling studies

Cordey, J.G.; Balet, B.; Campbell, D.J.; Challis, C.; Christiansen, J.; Gormezano, C.; Gowers, C.; Muir, D.G.; Righi, E.; Saibene, G.; Stubberfield, P.M.; Thomsen, K.

doi:10.1088/0741-3335/38/12a/006

Cited by 55 publications

(46 citation statements)

References 4 publications

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“…The principle of similarity assumes that physics is independent of the size scale. Accordingly, it has been demonstrated that tokamaks of different physical size but similar nondimensional parameters will have the same energy transport [23][24][25].…”

Section: The Expectation For the Fluctuation Level Versus Nondimensiomentioning

confidence: 99%

“…If energy transport is dominated by plasma physics, transport coefficients, normalised to the Bohm value χ B ≡ T /eB, can be expressed as functions of three dimensionless parameters χ ≡ χ B F (ρ * , ν * , β) at fixed safety factor q, plasma geometry, and ratio T e /T i [21,22,25]; ρ * (≡ ρ i /a) is the normalized gyroradius, ν * the collisionality and β the ratio of kinetic to magnetic pressure. The confinement scaling with these parameters provide the basis for predicting the performance of the next step machines.…”

Section: The Expectation For the Fluctuation Level Versus Nondimensiomentioning

confidence: 99%

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Scaling laws of density fluctuations in tokamak plasmas

Hennequin

2006

Comptes Rendus. Physique

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Section: The Expectation For the Fluctuation Level Versus Nondimensiomentioning

confidence: 99%

Section: The Expectation For the Fluctuation Level Versus Nondimensiomentioning

confidence: 99%

Scaling laws of density fluctuations in tokamak plasmas

Hennequin

2006

Comptes Rendus. Physique

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“…The difference in confinement between hydrogenic and helium-4 plasmas can also be expressed in terms of non-dimensional parameters. For a given configuration and q-profile, single ion species equipartioned plasmas dominated by high-β transport have been shown theoretically [39][40][41] to have a normalized confinement time, ω ci τ E , where ω ci is the ion Larmor frequency, which is a function of the non-dimensional plasma parameters ρ * i , β and…”

Section: Non-dimensional Parametersmentioning

confidence: 99%

ELMy H-modes in JET helium-4 plasmas

McDonald

Cordey

Righi³

et al. 2004

Plasma Phys. Control. Fusion

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ELMy H-modes in helium-4 plasmas provide valuable information on ELMy H-mode physics as well as a possible early low activation operational phase for next-step tokamaks, such as ITER. With this in mind, a series of helium-4 H-mode experiments were performed on JET with pure helium-4 NBI auxiliary heating (up to 12 MW). A set of ELMy H-mode plasmas were produced, in both the Type I ELM regime and a second regime, which showed characteristics similar to the deuterium Type III regime, but with a reverse ELM frequency dependence on power. Sawteeth were also observed, and had similar behaviour to those seen in deuterium. Compared with deuterium plasmas, Type I ELMy H-mode confinement is seen to be 28 ± 6% poorer in helium-4 plasmas and the L-H power threshold 42 ± 10% larger. This is the opposite of the behaviour predicted by experimental isotope mass scalings from hydrogenic plasmas.

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“…For example in the L-mode, the beneficial effect of triangularity on density buildup is much weaker or not present, suggesting that different physics is important under these conditions. The parametrization of the density profiles is made using the dimensionless expressions ρ * , ν * and β t [12,13] used in a special definition suitable for the plasma edge. This corresponds to a collisonal high-β ansatz for the underlying transport [14].…”

Section: Introductionmentioning

confidence: 99%

Scaling of the pedestal density in type-I ELMy H-mode discharges and the impact of upper and lower triangularity in JET and ASDEX Upgrade

Kallenbach

Beurskens²,

Korotkov

et al. 2002

Nucl. Fusion

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Experiments have been performed to disentangle the individual role of upper and lower triangularity on density buildup of lower single null, type-I ELMy H-mode discharges in JET. Comparison with corresponding data from ASDEX Upgrade allowed us to determine a dimensionless representation of the relation between the main chamber recycling and core density and to widen the triangularity variation in the data base. To incorporate the recycling flux density in a dimensionless form, an effective scrape-off layer density n e,SOL ∝ 0.5 is introduced allowing us to parametrize and scale the core density by the density rise factorn e /n e,SOL . The scaling uses edge-specific definitions of normalized Larmor radius, collisionality and beta. Rewritten in dimensional form, a behaviour is found which is very similar to energy confinement scalings for the ELM-averaged conditions considered here: the density rise factor exhibits an almost linear dependence on plasma current, a weak negative toroidal field dependence as well as power degradation. While a pronounced positive dependence of density buildup on the upper triangularity is observed, no significant correlation with the lower triangularity is found. In particular the dependences on plasma current and upper triangularity emphasize the importance of transport physics for the density buildup.

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A review of the dimensionless parameter scaling studies

Cited by 55 publications

References 4 publications

Scaling laws of density fluctuations in tokamak plasmas

Scaling laws of density fluctuations in tokamak plasmas

ELMy H-modes in JET helium-4 plasmas

Scaling of the pedestal density in type-I ELMy H-mode discharges and the impact of upper and lower triangularity in JET and ASDEX Upgrade

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