Experimental investigation of vapor shielding effects induced by ELM-like pulsed plasma loads using the double plasma gun device

Sakuma, I.; Kikuchi, Yusuke; Kitagawa, Y.; Asai, Yusuke; Onishi, Keizo; Fukumoto, N.; Nagata, Masayoshi

doi:10.1016/j.jnucmat.2014.10.020

Cited by 17 publications

(7 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The energy density of 1 MJ/m 2 was irradiated in 0.2 ms. The detail of the PG experiment can be found in refs [ ]. With this device, an Al‐coated W specimen was irradiated.…”

Section: Resultsmentioning

confidence: 99%

Simulation study on the vapour shielding at solid walls under transient heat loads using weighted particle model

Ibano

Kikuchi

Tanaka

et al. 2018

Contributions to Plasma Physics

Self Cite

View full text Add to dashboard Cite

Vapour shielding at solid walls is expected for a future fusion reactor in case of large heat load due to transient events. In order to estimate the dissipation of the incoming heat flux by the vapour shielding, a simulation code called PIXY, using a weighted particle model, is developed. First, a validation study is undertaken. Vapour shielding of an aluminium‐coated tungsten specimen was experimentally observed in a plasma gun device. Results are reproduced by the PIXY simulation. Then, the code is applied to the transient edge‐localized mode (ELM) heat flux for the reactor condition. It was found that the ion–neutral collision, as well as radiative cooling, is a dominant phenomenon for the heat flux dissipation in both cases. As the maximum heat flux increases, oscillating phenomena appear remarkably, which have been observed in other experimental studies on vapour shielding.

show abstract

“…The energy density of 1 MJ/m 2 was irradiated in 0.2 ms. The detail of the PG experiment can be found in refs [ ]. With this device, an Al‐coated W specimen was irradiated.…”

Section: Resultsmentioning

confidence: 99%

Simulation study on the vapour shielding at solid walls under transient heat loads using weighted particle model

Ibano

Kikuchi

Tanaka

et al. 2018

Contributions to Plasma Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Another plasma gun device, a magnetized coaxial plasma gun (MCPG) [9,10], has also been used for vapor shielding studies. The device can produce 1 MJ m −2 plasma loads over a pulse length of 0.2 ms. A special feature of this device is its specimen temperature measurement system.…”

Section: Estimation Of Suppressed Erosion By Vapor Shielding At Be An...mentioning

confidence: 99%

Estimation of suppressed erosion by vapor shielding at Be and W walls under transient loads

et al. 2019

View full text Add to dashboard Cite

In ITER and future fusion devices, wall erosion caused by transient heat loads, edge-localized modes (ELMs) and disruptions is a serious concern. Suppression of the erosion occurs when a significant vapor emission happens under the heat loads, which is known as vapor shielding. Estimation of the suppressed erosion amount is essential for life time analysis and reactor design. In this study, we developed a particle-in-cell simulation code for the vapor shielding, PIXY, and applied the code to the erosion estimation for Be and W walls under a pulsed heat flux of 1-20 GW m −2 within 0.2 ms, which simulates a short-duration ELM pulse. Heat fluxes reaching the wall are recorded separately for electrons and ions, and reveal effective physical processes during the vapor shielding at Be and W walls. Then, for these walls, the total erosion amounts with and without vapor shielding are evaluated and compared. Estimated total erosion is larger for the Be wall up to 10 GW m −2 . The Be wall erosion becomes saturated for the heat flux >10 GW m −2 due to its effective shielding, while the estimated W wall erosion eventually overcomes the Be wall erosion. In the short-time scale studied in this paper, effective radiation cooling by W vapor clouds is not observed. A simple wall life time analysis based on the estimated erosion rate shows 10 mm of W wall will survive 10 7 ELM loads with energy density less than 1 MJ m −2 .

show abstract

“…A large number of studies have been carried out on the plasma surface interaction (PSI) of divertors during H-mode plasma operation with type I ELMs [1][2][3][4][5][6], including experimental simulation and theoretical calculation. The heat loads during the International Thermonuclear Experimental Reactor (ITER) ELMs-I are estimated to be Q ELM = (1-3) MJ m −2 , with a pulse length of 0.1-1 ms [1,4,6,7]. The high energy may cause the breakdown and melting of the divertor W target and movement of the melting layer, etc, resulting in shortening the lifetime of the divertors.…”

Section: Introductionmentioning

confidence: 99%

“…NSC-KIPT also did other research on ITER with QSPA/QSPA-M. The Graduate School of Engineering at Hyogo University in Japan has carried out research related to a compact toroidal plasma with an external magnetic field and surface damage characteristics of material for ITER [3,4,6]. The Troitsk Institute for Innovation and Fusion Research has studied plasma/material interaction in disruption simulation experiments at the plasma gun facility MK-200 UG [7,11].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Experimental study on plasma generated by a tapered coaxial accelerator and its damage effects on a tungsten target at different angles

Zhao¹,

Chen²,

Song³

et al. 2022

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

Plasma wall interaction (PWI) will occur inevitably during the operation of Tokamak. The coxial gun device has low operation cost and parameters of plasma produced by the gun are close to those of type I ELM, therefore, the coaxial gun is suitable in simulation experiment as heat-flux sources of transient events such as type I ELM under the condition of H-mode in ITER. In this paper, the plasma generated by the discharge of a tapered coaxial accelerator thermal shock on a tungsten target to simulate the damage effect of the divertor. The plasma parameters are measured in the experiment. The velocity of the plasma is 41.7 km/s, and the kinetic energy of a single hydrogen ion is 9.2 eV. The energy density at the center of the plasma can reach 1.5 MJ/m2, and the density can reach about 2.78×1015 /cm3. The reflection of plasma in the process of exposure at different angles is observed. It is observed that droplets of millimeter size splash from the target. Traces of liquid flow are observed on the surface of the target, which shows that there is a melting process on the surface of target. The mass loss of the target is in the order of mg after 20 pules. The ablation and residual stress of the target surface both decrease with the decrease of the angle. This is because the accumulated energy per unit area of the target surface decreases with the decrease of the angle. These results help us to better understand the damage effect of tungsten target for further research.

show abstract

Experimental investigation of vapor shielding effects induced by ELM-like pulsed plasma loads using the double plasma gun device

Cited by 17 publications

References 7 publications

Simulation study on the vapour shielding at solid walls under transient heat loads using weighted particle model

Simulation study on the vapour shielding at solid walls under transient heat loads using weighted particle model

Estimation of suppressed erosion by vapor shielding at Be and W walls under transient loads

Experimental study on plasma generated by a tapered coaxial accelerator and its damage effects on a tungsten target at different angles

Contact Info

Product

Resources

About