Efficiency of water coolant for DEMO divertor

Fetzer, Renate; Igitkhanov, Yuri; Базылев, Б.

doi:10.1016/j.fusengdes.2014.11.012

Cited by 11 publications

(4 citation statements)

References 10 publications

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“…Between ELMs, in the solidified stage, there is a temperature difference between hot spot and cool spot. Figure 6 show the evolution of the maximum temperatures for tungsten and EUROFER for DEMOI operation with unmitigated Type I ELMs and PWR like cooling conditions [3]. The distance between neighboring channels is 5 mm.…”

Section: Effect Of Repetitive Elm Loadsmentioning

confidence: 99%

“…The channels are symmetrically positioned in the first wall (FW). To stay within the allowed temperature window for materials the pressurized water reactors like water cooling conditions with inlet temperature 325 °C, pressure 15.5 MPa and velocity in the range of 20 m s −1 is used [2,3]. In calculation heat conductivity of W and EUROFER under neutron irradiation, expected in DEMO, are considered reduced by 10% compare with the un-irradiated case.…”

Section: Introductionmentioning

confidence: 99%

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Thermo-mechanical analysis of the DEMO FW module

Igitkhanov¹,

Fetzer²,

Boccaccini³

et al. 2015

Phys. Scr.

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Thermomechanical performance of the first wall (FW) W/EUROFER sandwich type module is analyzed under DEMO reactor conditions. Engineering heat loads to the FW panels are estimated for steady state operation with the edge localized modes (ELMs). Calculations carried out by MEMOS code show the inhomogeneity of the material temperature due to discrete location of the water cooling tubes embedded into EUROFER. The hot spots are formed in the W armor and EUROFER between the cooling sectors and depend on the distance of their mutual locations. The bending stress due to vertical temperature gradients in W and EUROFER layers is calculated and remains smaller than the ultimate tensile stress for expected temperatures. Calculations show that under the Type I ELMs expected in DEMO the W surface melts at the ELMs peak positions and solidifies between ELMs. There is no temperature difference found between hot and cool spots during ELMs.

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Section: Effect Of Repetitive Elm Loadsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Thermo-mechanical analysis of the DEMO FW module

Igitkhanov¹,

Fetzer²,

Boccaccini³

et al. 2015

Phys. Scr.

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“…While tungsten will be used as the plasma facing material (PFM) for the divertor region in ITER [1], the duty cycle and particle fluence in the divertor of a fusion power-plant (i.e. DEMO) will exceed those in ITER considerably [2][3][4]. Furthermore neutron damage will degrade the material properties significantly over time [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

“…It has a low evaporation rate and a high potential power exhaust capability, predicted to be up to 20-25 MW m −2 [11,12]. Performance limits of tin in DEMO relevant conditions are primarily defined by the tin impurity level in the plasma core and thus by the sputtering/ Nuclear Fusion Tin re-deposition and erosion measured by cavity-ring-down-spectroscopy under a high flux plasma beam V. Kvon 1,2 , R. Al 2 , K. Bystrov 2 , F.J.J. Peeters 2 , M.C.M.…”

Section: Introductionmentioning

confidence: 99%

Tin re-deposition and erosion measured by cavity-ring-down-spectroscopy under a high flux plasma beam

Kvon¹,

Al²,

Bystrov³

et al. 2017

Nucl. Fusion

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Cavity-Ring-Down Spectroscopy (CRDS) was implemented to measure the re-deposition of liquid tin under a high flux plasma beam in the linear plasma device Pilot-PSI. A capillary porous system (CPS) consisting of a molybdenum cup and tungsten meshes (pores diameters of 0.2 mm and 0.44 mm) was filled with tin and exposed to argon plasma. The absorption of a UV laser-beam at 286.331 nm was used to determine a number of sputtered neutral tin atoms. The incoming flux of argon ions of ~50 eV was 1.6−2.7x10 23 m-2 s-1 , and the sample temperature measured by pyrometry varied from 850 °C to 1200 °C during exposures. The use of CRDS for measuring absolute number of particles under such plasma exposure was demonstrated for the first time. The number of sputtered tin particles in the cavity region assuming no losses would be expected to be 5.5x10 11 −1.2x10 12 while CRDS measurements showed only 5.7−9.9x10 8. About 98−99.8% of sputtered particles were therefore found to not reach the CRDS observation volume. Spectroscopic ratios of Sn I to Sn II ions, as well as equilibrium considerations, indicate that fast ionization as well as plasma entrainment of neutrals is responsible for the discrepancy. This would lead to high re-deposition rates, implying a lowered contamination rate of core plasma and lower required replenishment rates at high-flux conditions than would otherwise be expected.

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