Formation and sustainment of internal transport barriers in the International Thermonuclear Experimental Reactor with the baseline heating mix

Poli, F. M.; Kessel, C.

doi:10.1063/1.4802937

Cited by 7 publications

(9 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Development of feasible ITER operation scenarios requires an integrated tokamak discharge simulator, such as CORSICA [13,14], DINA-CH/CRONOS [9,15,16], TSC [17,18], PTRANSP [19], JINTRAC/CREATE-NL [20,21], and ETS [22,23]. The DINA-CH/CRONOS simulator was developed by combining a free-boundary equilibrium evolution code, DINA-CH, and an advanced transport and source modelling code, CRONOS.…”

Section: Introductionmentioning

confidence: 99%

CORSICA modelling of ITER hybrid operation scenarios

et al. 2016

View full text Add to dashboard Cite

The hybrid operating mode observed in several tokamaks is characterized by further enhancement over the high plasma confinement (H-mode) associated with reduced magneto-hydro-dynamic (MHD) instabilities linked to a stationary flat safety factor () profile in the core region. The proposed ITER hybrid operation is currently aiming at operating for a long burn duration (>1000 s) with a moderate fusion power multiplication factor, , of at least 5. This paper presents candidate ITER hybrid operation scenarios developed using a free-boundary transport modelling code, CORSICA, taking all relevant physics and engineering constraints into account. The ITER hybrid operation scenarios have been developed by tailoring the 15 MA baseline ITER inductive H-mode scenario. Accessible operation conditions for ITER hybrid operation and achievable range of plasma parameters have been investigated considering uncertainties on the plasma confinement and transport. ITER operation capability for avoiding the poloidal field coil current, field and force limits has been examined by applying different current ramp rates, flat-top plasma currents and densities, and pre-magnetization of the poloidal field coils. Various combinations of heating and current drive (H&CD) schemes have been applied to study several physics issues, such as the plasma current density profile tailoring, enhancement of the plasma energy confinement and fusion power generation. A parameterized edge pedestal model based on EPED1 added to the CORSICA code has been applied to hybrid operation scenarios. Finally, fully self-consistent free-boundary transport simulations have been performed to provide information on the poloidal field coil voltage demands and to study the controllability with the ITER controllers.

show abstract

Section: Introductionmentioning

confidence: 99%

CORSICA modelling of ITER hybrid operation scenarios

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Based on predictive simulations performed on a number of scenarios with different H/CD mixes and with a range of magnetic shear profiles, we find that the CDBM qualitatively reproduces features observed in experiments, such as (1) the flattening of the central temperature in strong reverse shear plasmas, (2) the steepening of the temperature gradient and ITB triggering at the time and location where the shear is zero [16];…”

Section: Transport Modelsmentioning

confidence: 57%

“…The formation and sustainment of stationary current and ITBs with the baseline heating mix has been discussed in a previous work [16]. However, since the EC steering configuration used in the simulations presented herein is based on those findings, the main results of that study are summarized in this section.…”

Section: Towards Stationary Solutions With Itbmentioning

confidence: 93%

“…The lower current drive efficiency of the UL is compensated by the sustainment of a larger bootstrap current. It was found that the steering configuration that maximizes the total current (bootstrap plus EC driven current) has two-third of the injected power delivered to the UL and the EL deposition close to mid-radius [16].…”

Section: Towards Stationary Solutions With Itbmentioning

confidence: 99%

“…The baseline heating mix, which uses 20 MW of EC, up to 20 MW of ion cyclotron (IC) and 33 MW of NB, was previously analyzed [16], indicating that a stationary current and ITBs can be sustained by sharing the EC power between the equatorial and the upper launcher. Here, the baseline heating mix is compared with configurations that use LHCD.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

External heating and current drive source requirements towards steady-state operation in ITER

et al. 2014

View full text Add to dashboard Cite

Steady state scenarios envisaged for ITER aim at optimizing the bootstrap current, while maintaining sufficient confinement and stability to provide the necessary fusion yield. Non-inductive scenarios will need to operate with internal transport barriers (ITBs) in order to reach adequate fusion gain at typical currents of 9 MA. However, the large pressure gradients associated with ITBs in regions of weak or negative magnetic shear can be conducive to ideal MHD instabilities, reducing the no-wall limit. The E × B flow shear from toroidal plasma rotation is expected to be low in ITER, with a major role in the ITB dynamics being played by magnetic geometry. Combinations of heating and current drive (H/CD) sources that sustain reversed magnetic shear profiles throughout the discharge are the focus of this work. Time-dependent transport simulations indicate that a combination of electron cyclotron (EC) and lower hybrid (LH) waves is a promising route towards steady state operation in ITER. The LH forms and sustains expanded barriers and the EC deposition at mid-radius freezes the bootstrap current profile stabilizing the barrier and leading to confinement levels 50% higher than typical H-mode energy confinement times. Using LH spectra with spectrum centred on parallel refractive index of 1.75–1.85, the performance of these plasma scenarios is close to the ITER target of 9 MA non-inductive current, global confinement gain H98 = 1.6 and fusion gain Q = 5.

show abstract