The softening of current quenches in JT-60U

Yoshino, R.; Neyatani, Y.; Hosogane, N.; Wolfe, S.; Matsukawa, M.; Ninomiya, H.

doi:10.1088/0029-5515/33/11/i02

Cited by 39 publications

(31 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This aims at ensuring safe and reliable plasma operations and avoiding long downtime periods needed by repairs. Runaway electrons have been studied on many machines in the world since early tokamaks ( [1]) but also on recent larger machines such as JET [2,3,4,5], JT-60U [6,7], Tore Supra [8,9], TEXTOR [10,11], DIII-D [12,13,14], FTU [15], TFTR [16]. Experiments have focused on documenting their generation conditions as a function of operational or physics parameters.…”

Section: Introductionmentioning

confidence: 99%

Runaway electron beam generation and mitigation during disruptions at JET-ILW

Reux¹,

Plyusnin²,

Alper³

et al. 2015

Nucl. Fusion

115

129

View full text Add to dashboard Cite

Disruptions are a major operational concern for next generation tokamaks, including ITER. They may generate excessive heat loads on plasma facing components, large electromagnetic forces in the machine structures and several MA of multi-MeV runaway electrons. A more complete understanding of the runaway generation processes and methods to suppress them is necessary to ensure safe and reliable operation of future tokamaks. Runaway electrons were studied at JET-ILW showing that their generation dependencies (accelerating electric field, avalanche critical field, toroidal field, MHD fluctuations) are in agreement with current theories.

show abstract

Section: Introductionmentioning

confidence: 99%

Runaway electron beam generation and mitigation during disruptions at JET-ILW

Reux¹,

Plyusnin²,

Alper³

et al. 2015

Nucl. Fusion

115

129

View full text Add to dashboard Cite

show abstract

“…For example, assuming the halo current phenomenon during the vertical displacement events (VDE) disruption, there is a possibility that the electromagnetic force would be suppressed by controlling the poloidal cross section 16) of the core plasma, and the temperature and the density of the scrape-off layer. 17) In summary, a divertor magnetic configuration is proposed that expands the divertor channels by applying an additional cusp-like magnetic field in the divertor region of the tokamak device. This not only allows a significant reduction of the heat load due to expansion of the divertor channels but also hardly affects the original magnetic configuration of the core plasma.…”

Section: Discussionmentioning

confidence: 99%

Guidance of Divertor Channel by Cusp-Like Magnetic Field for Tokamak Devices

Takase

2001

J. Phys. Soc. Jpn.

View full text Add to dashboard Cite

A divertor magnetic configuration is proposed that significantly reduces heat load on the divertor plates in tokamak devices. The proposed configuration utilizes an additional cusp-like magnetic field generated by four poloidal coils for expanding the divertor channels. This not only allows a significant reduction of the heat load due to expansion of the divertor channels but also hardly affects the original magnetic configuration of the core plasma. These special features are useful for fusion reactor designs.Progress has been made in tokamak confinement research to such an extent that reactor design studies are now well advanced. Such studies, 1) however, have revealed some major issues that must be resolved in order to design tokamak reactors. For example, one issue is how to achieve reliable heat removal on a divertor plate. In the case of typical designs, e.g., the International Thermonuclear Experimental Reactor (ITER), the peak heat load is expected to be more than 20 MW/m 2 with a half-width of the divertor channel being 0.05-0.1 m. The heat removal issue is common to magnetic confinement fusion devices. If the half-width of the divertor channel (magnetic field lines for the divertor) on the divertor plate becomes larger than 1 m, then the peak heat load is expected to be less than 1 MW/m 2 . This allows easier maintenance of the divertor system and it is the key requirement for magnetic confinement fusion reactor designs. Furthermore, as a result of the reduction of the heat load, the core plasma temperature can be raised and the operation region for the core plasma can be extended.Recently, some concepts for resolving the abovementioned issue have been proposed for both tokamak and stellarator approaches. 2-9) For ITER, a vertical target is adopted, which is located almost parallel to the divertor channel. Although the effective area for the heat load is increased by adopting the vertical target, there is a possibility that the merit of the vertical target is not fully demonstrated by the decrease of the effective area due to the plasma positional instability.Another proposed concept 7, 8) is a divertor configuration that guides the outward-flowing plasma particles and associated heat flux to a remote area with magnetic field strength, thereby allowing a large expansion of the divertor channel and hence a significant reduction of the heat load, which is a necessary requirement for reliable heat removal. This concept is similar to that of the bun- *

show abstract

“…3 − 2∆I max P /I P , with I max P being the maximum current of the current spike occurring after the thermal quench [7]. The probability for runaway generation is given in figure 1a as a function of the maximum electric field during the current quench.…”

Section: Runaway Electron Generationmentioning

confidence: 99%

Runaway generation during disruptions in JET and TEXTOR

Lehnen¹,

Abdullaev²,

Arnoux

et al. 2009

Journal of Nuclear Materials

View full text Add to dashboard Cite

Runaway electrons generated during ITER disruptions are of concern for the integrity of the plasma facing components. It is expected that a power of up to 8 GW is exposed to ITER PFCs. We present in this article observations from JET and TEXTOR on the generation of runaways and the heat load deposition. Suppression techniques like massive gas injection and resonant magnetic perturbations are discussed.

show abstract

The softening of current quenches in JT-60U

Cited by 39 publications

References 10 publications

Runaway electron beam generation and mitigation during disruptions at JET-ILW

Runaway electron beam generation and mitigation during disruptions at JET-ILW

Guidance of Divertor Channel by Cusp-Like Magnetic Field for Tokamak Devices

Runaway generation during disruptions in JET and TEXTOR

Contact Info

Product

Resources

About