The first results of deuterium retention on EAST with a full graphite wall via particle balance

Cao, Bin; LI, Jiangang; Hu, Jian; WANG, Houyin

doi:10.1088/2058-6272/aa8a5f

Cited by 2 publications

(6 citation statements)

References 33 publications

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“…The gas balance method was used for analyzing the retention of fuel particles in the wall, as described in [25,35]. The fundamental principle of this method is that the number of retained particles is approximately equal to the number of puffed particles minus the number of pumped particles.…”

Section: Gas Balance Methodsmentioning

confidence: 99%

“…charges. Fresh Li-coated film can absorb lots of D particles, which causes fuel particle retention [25,38] and a decrease in fuel particle recycling. The fuel particle recycling is defined as the process-the average fuel particle leaves and re-enters the plasma many times over the course of a discharge [2].…”

Section: Deuterium Retention With Li-coated W Wall By LI Oven Evapora...mentioning

confidence: 99%

“…Fuel particle wall retention includes two basic retention processes, i.e. short-term retention and long-term retention [4,25]. There are three fuel retention mechanisms: absorption, implantation and co-deposition.…”

Section: Introductionmentioning

confidence: 99%

“…Particle balance uses the difference between the injected and exhausted particles to calculate the retained particles, and post-mortem analysis uses thermal desorption spectrometry and Rutherford backscattering spectroscopy to analyze the fuel retention after the experiment [27]. The particle balance method has been successfully applied in the Tore Supra [27], TFTR [13], JT-60 U [28], ASDEX Upgrade [29], JET [30], DIII-D [31] and EAST [25]. In the carbon wall machine, Tore Supra, it was found that a disruption significantly increased post-discharge outgassing, with the total released gas increasing with the total energy [32].…”

Section: Introductionmentioning

confidence: 99%

“…In the EAST experiment with a Li-coated full graphite wall, the average deuterium retention fraction was ~20%-40%. Furthermore, it was observed that disruptions increased wall outgassing [25]. In EAST, Li coating was applied to the first wall to keep a clean wall environment.…”

Section: Introductionmentioning

confidence: 99%

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Deuterium retention characteristics in Li film by coating and during flowing liquid Li limiter operation in experimental advanced superconducting tokamak

Zuo

Maingi

et al. 2020

Plasma Phys. Control. Fusion

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Lithium (Li) is a promising low-Z material for particle recycling and impurity control to improve plasma performance in fusion devices. In the experimental advanced superconducting tokamak (EAST), Li coating has become a routine method for wall conditioning, and a flowing liquid Li (FLiLi) limiter has been successfully tested several times. Deuterium retention characteristics in the Li film coated on the international thermonuclear experimental reactor-like tungsten divertor and FLiLi during plasma discharges, which is important for the utilization of Li in future fusion devices, were investigated in EAST. It is found that the absorption of the fuel particles by Li coatings decreases gradually, and recycling gradually increases over a series of discharges. The maximum net amount of deuterium retained reached ∼0.8 g, corresponding to 12% deuterium in the Li. This corresponds to a whole day’s worth of shots with a total of 87 plasma discharges and a total of ∼640s plasma time after 11.75 g Li was deposited. Compared to the Li coating, it is shown that FLiLi continuously traps fuel particles and achieves a higher deuterium retention ratio over both the short- and long-term, leading to lower recycling. Meanwhile, it is also observed that the fuel particle retention ratio increases when FLiLi is closer to the plasma. This result is likely due to higher plasma heating power and limiter temperature, which cause an increased Li efflux from FLiLi due to a higher limiter temperature, which then redeposits on the other plasma-facing surfaces and increases fuel particle absorption. It is estimated that ⩾80% of the retained D particles are captured by the continual renewal of the Li redeposition film during the FLiLi operation. This investigation would also be useful for D/T retention in future fusion devices if Li is used as a plasma-facing component.

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Section: Gas Balance Methodsmentioning

confidence: 99%

Section: Deuterium Retention With Li-coated W Wall By LI Oven Evapora...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Deuterium retention characteristics in Li film by coating and during flowing liquid Li limiter operation in experimental advanced superconducting tokamak

Zuo

Maingi

et al. 2020

Plasma Phys. Control. Fusion

Self Cite

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Experimental study of detachment density threshold in L-mode plasmas on EAST

Meng

Liu

et al. 2020

Plasma Phys. Control. Fusion

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One of the critical challenges for long pulse operation of ITER and future fusion reactors is the excessively high heat and particle fluxes on the divertor targets. The divertor detachment offers an effective way for the control of steady state heat flux and erosion at the divertor target. Dedicated experiments have been systematically performed for both H-mode and L-mode plasmas on EAST with ITER-like W divertor in the last two years to further advance detachment physics understanding. The detachment is identified by the rollover of divertor peak particle flux near the strike point during the density ramping up, which correlates with the reduction of electron temperature down to 5 eV, the increase of D δ /D α ratio and radiated power. It has been demonstrated that the more closed divertor has a lower density threshold at the onset of detachment on EAST. Furthermore, the detachment density threshold will be reduced when the strike point moves towards the divertor corner. The onset of detachment exhibits a strong asymmetry between inner and outer targets, with the inner target accessing detachment at lower density due to the lower electron temperature, as expected. The effects of the heating power and plasma current on the detachment onset were also investigated. The experimental results show that the density at detachment onset is lower in L-mode relative to H-mode, and increases with the heating power. The detachment density threshold normalized to the Greenwald density limit is lower at a high plasma current.

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The first results of deuterium retention on EAST with a full graphite wall via particle balance

Cited by 2 publications

References 33 publications

Deuterium retention characteristics in Li film by coating and during flowing liquid Li limiter operation in experimental advanced superconducting tokamak

Deuterium retention characteristics in Li film by coating and during flowing liquid Li limiter operation in experimental advanced superconducting tokamak

Experimental study of detachment density threshold in L-mode plasmas on EAST

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