Uncertainties associated with extrapolating L-mode energy confinement to ITER and CIT

  title={Uncertainties associated with extrapolating L-mode energy confinement to ITER and CIT},
  author={Kurt S. Riedel and S M Kaye},
  journal={Nuclear Fusion},
  pages={731 - 742}
The authors apply a two-step tokamak regression procedure to L-mode confinement data. The resulting scaling expression for τE: is similar to other published scaling expressions. Using the random coeffcient model, tokamak-to-tokamak variations are included in the estimate of the uncertainty. The uncertainty factor in the predicted confinement times is calculated to be 19% for ITER and 35% for CIT. The confinement uncertainties are dominated by the propagation of uncertainties arising from the… 
14 Citations
Scalings for Tokamak Energy Confinement
Two new scaling expressions for tokamak L-mode energy confinement are proposed, namely a power law scaling and an offset-linear scaling, which can be transformed to forms very close to most of the common scaling expressions.
Dimensionality correct power law scaling expressions for L-mode confinement
The random coefficient two-stage regression algorithm is applied to a neutral beam heated limiter subset of the ITER L-mode database as well as a combined dataset and a scaling similar to the Goldston scaling is found for the neutral beam limiter dataset.
Interval estimation of global H-mode energy confinement in ITER
This paper treats some fundamental and practical aspects of interval estimation of the prospective thermal H-mode confinement time in ITER. Some basic definitions of an interval estimate are given
Extrapolation of tokamak energy confinement to Next Step Devices
The extrapolation of energy confinement to the conditions of a Next Step tokamak, to operate with an ignited DT plasma, is an essential ingredient of the data base needed for such a device. The
Application of plasma physics constraints to confinement data
A subset of the ITER L-mode and H-mode confinement data is tested against the constraints imposed by various theoretical models for thermal plasma transport. Matrix algebra is used to facilitate such
β scaling of confinement
Empirical scaling laws (Goldston, Kaye-Goldston, ITER89P and ITER93H) for the confinement time τE in tokamaks depend on dimensionless global plasma parameters in a way which is difficult to associate
Influence of the divertor on the L mode confinement in ASDEX
Results of confinement studies on an L mode database covering 10 years of operation of ASDEX are presented. During this time, the ASDEX divertor was modified several times. Scaling expressions for
The problem of projecting the energy confinement properties of future devices is a long-standing one in toroidal confinement research. While substantial progress has been made in characterizing the
Random Coefficient H-mode Confinement Scalings
The random coefficient two-stage regression algorithm with the collisional Maxwell-Vlasov constraint is applied to the ITER H-mode confinement database, and the data violate the collisionals at the 10-30% significance level, probably owing to radiation losses.
Ion temperature profile simulation of JT-60 and TFTR plasmas with ion temperature gradient mode transport models
Ion temperature profiles of neutral beam heated plasmas in JT-60 and TFTR have been simulated using models of ion thermal diffusivity, χi, based on ion temperature gradient mode (ηi mode) turbulence


Status of global energy confinement studies
Empirical scaling expressions, reflecting the parametric dependence of the L‐mode energy confinement time, have been used not only as benchmarks for tokamak operation and theories of energy
Tokamak confinement in relation to plateau scaling
It is shown that a plateau-like scaling gives a good overall fit to energy confinement data of Ohmic and L-regime discharges for devices ranging from Pulsator to JET. Systematic deviations become
Energy confinement properties of H-mode discharges in the DIII-D tokamak
Neutral beam heated DIII-D expanded boundary divertor discharges have exhibited ASDEX-like H-mode behaviour over a wide parameter range. The deuterium H-mode energy confinement of 120 ms remained
The jackknife, the bootstrap, and other resampling plans
The Jackknife Estimate of Bias The Jackknife Estimate of Variance Bias of the Jackknife Variance Estimate The Bootstrap The Infinitesimal Jackknife The Delta Method and the Influence Function
Global energy confinement scaling for neutral-beam-heated tokamaks
A total of 677 representative discharges from seven neutral-beam-heated tokamaks have been used to study the parametric scaling of global energy confinement time. Contributions to this data base were
Survey of energy confinement expressions
    Max-Planck-Institut fur Plasmaphysik, Garching, personal communication
    • 1989
    Scaling'expressions for ITER, ITER Rep. IL-Ph-4-9-7, to be submitted to
    • Nucl. Fusion