Profile consistency on TFTR

Fredrickson, E. D.; McGuire, K.; Goldston, Robert James; Bell, M.G.; Grek, B.; Johnson, D. W.; Morris, A.W.; Stauffer, F. J.; Taylor, G.; Zarnstorff, M. C.

doi:10.1088/0029-5515/27/11/012

Cited by 33 publications

(27 citation statements)

References 19 publications

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“…13 for the case of carbon pellet perturbations. That study confirmed profile resiliency of the electron temperature 14 following the pellet, in addition to observing that the electron stored energy actually increases transiently as a result of the perturbation. Most interesting, however, was that in contrast with the large degradation and slow recovery suffered by supershots, L-Mode plasmas suffered no loss of stored energy during deep carbon pellet perturbations.…”

Section: Introductionsupporting

confidence: 74%

Transitionless enhanced confinement and the role of radial electric field shear

Ernst¹,

Bell²,

Bell³

et al. 2000

Physics of Plasmas

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Evidence is presented for the role of radial electric field shear in enhanced confinement regimes attained without sharp bifurcations or transitions. Temperature scans at constant density, created in the reheat phase following deuterium pellet injection into supershot plasmas in the Tokamak Fusion Test Reactor [J. D. Strachan, et al., Phys. Rev. Lett. 58, 1004 (1987)] are simulated using a physics-based transport model. The slow reheat of the ion temperature profile, during which the temperature nearly doubles, is not explained by relatively comprehensive models of transport due to Ion Temperature Gradient Driven Turbulence (ITGDT), which depends primarily on the (unchanging) electron density gradient. An extended model, including the suppression of toroidal ITGDT by self-consistent radial electric field shear, does reproduce the reheat phase. The extended reheat at constant density is observed in supershot but not L-Mode plasmas.

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Section: Introductionsupporting

confidence: 74%

Transitionless enhanced confinement and the role of radial electric field shear

Ernst¹,

Bell²,

Bell³

et al. 2000

Physics of Plasmas

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“…These measurements are the second harmonic electron cyclotron black-body emission as measured by a Michelson interferometer [51] and are averaged over a couple of sawtooth periods. Further, it is shown elsewhere [7,8,56] that the normalized TFTR temperature profiles (i.e. T e (r)/T e (0) versus r/a) are invariant whether the discharge is heated ohmically or with additional low-power neutral beam heating.…”

Section: Fig 4 Comparison Of [{T E )/T Eo L Ex P With [(T E )/T El ]^...mentioning

confidence: 99%

“…NUCLEAR FUSION, Vol.30, No. 10 (1990) In the literature, many authors [2][3][4][5][6][7][8][9][10][11][12][13] have proposed various different profile shapes to explain (either directly or indirectly) some or all of the observed general features of profile consistency. 1 The primary objective of some of these models was to understand the nature of the energy and particle transport processes in tokamak plasmas, while others concentrated on understanding the macroscopic stability of the plasma column for magnetohydrodynamic (MHD) modes (for example, via the minimum energy principle and the principle of minimum entropy production), with profile consistency as a by-product.…”

Section: Introductionmentioning

confidence: 99%

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Self-consistency of the principle of profile consistency results for sawtoothing tokamak discharges

et al. 1990

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DISCLAIMERThis i-eport was prepared as an accouni of +ork sponsored hy an agency uf the United States Government Neither (he United Slates Government nor jn> agency thereof, nor any of their employees, makes any warranty, express or implied. 01 assume* any legal liability or responsihilili for the accuracy, completeness, or usefulness af any infocmauon, apparatus, product. 01 process disclosed, or represents that its use would not infringe privately owned rights Refer ence herein to any specific commercial product, process, or service hy trade name, trademark, manufacturer, or otherwise docs (tot necessarily constitute or imply its endorsement, recom mendation, or favoring by the United States Government or any agency thereof The views and opinions of authors expressed herein do not necessarily state ur reflect those of the Vimlcd States Government or any agency (hereof •AT&T Microelectronics, Reading, PA 19612 **0ak Ridge National Laboratory, Oak Ridge, TN 37831 if \S 2 ABSTRACT The principle of profile consistency states that for fixed limiter safety factor q,, there exists unique natural equilibrium profile shapes for the a. current density j(r) [and consequently q(r)], and the electron temperature T (r) for any tokamak plasma independent of the shapes of the heating power deposition profiles. The mathematical statement of the three basic consequences of this principle for sawtoothing discharges [i.e., discharges with q(0) < 1) are: (1) (r^a) = F, M/q a > [= Vq a , empirically], (2) /T"" = F 5 (1/q_), and (3) a unique scaling law for the central electron S SO tl d temperature T , where r 1 is the sawtooth inversion radius [i.e., q(r^) = 1] and is the volume average T . Since for a given T (r), the ohmic current J(r) can be deduced from Ohm'3 law, given the function F^, the function F 2 is uniquely fixed and vice versa. Also given F^(Vq_), the central current density J Q = (V L /2nbRZ eff ) T|^2 = (I /*a 2 ) Fg(q a ), where the function F3 = (q a /q Q ) is uniquely fixed by F^ Here b = 6.53 * 10^ unA, and I , V L> Z ff >, R, a, and q are the plasma current, loop voltage, effective ion charge, major and minor radius, and the central safety factor, respectively. Thus for a fixed J(r) or T (r), the set of functions F^ F 2 , and F-, is uniquely fixed. Further, the principle of profile consistency [i.e., the existence of unique natural equilibrium profile shapes far J(r) and T e

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“…The a 2 dependence and the numerical factors in Eqs. (6) and 7are result* of the cylindrical approximation and the use of thermal diffusivities measured in a limited range of parameters.…”

Section: Eq (3) Asmentioning

confidence: 99%

Comments on experimental results of energy confinement of tokamak plasmas

Chu¹

1989

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This report was prepared as an account of work sponsored by un agents of the l»mted Slalcs-Govcrjimcnl Neiihcr the United States Ciovcrnmcni nos any agency thereof, nur an\ of their employee*, makes any warranty, express ur implied, ur .tssumc* any legal liability of responsi bility fur (he ai-Lurac;.. completeness*, «r u^fulricss of any informal reft, apparatus, product, or pru.css JiMjdrtcJ. or represent thai iH use would nui infringe priv-if^y uurcd rights Refer ence herein lu jn\ ?,pc.cif]C tomrncrcwJ product, process, or service hy lfa.de name, Jradcmark. manufacturer, or otherwise docs not ncvos.ifil* Luifeiiiutc ur imply it* endorsement, recant* mendji)«rt. ur fjtormg by the United Sli>;c* ^iuvcrnmem or any agency ihcreuf The views and opintun* t>f authors cipro«d herein do not nei:ca,iarjly Male or reflect those of the ('niied States Government 01 any jgency ihercof PPPL-2606 DE89 010315 COMMENTS ON EXPERIMENTAL RESULTS OF ENERGY CONFINEMENT OF TOKAMAK PLASMAS

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Profile consistency on TFTR

Cited by 33 publications

References 19 publications

Transitionless enhanced confinement and the role of radial electric field shear

Transitionless enhanced confinement and the role of radial electric field shear

Self-consistency of the principle of profile consistency results for sawtoothing tokamak discharges

Comments on experimental results of energy confinement of tokamak plasmas

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