Heat flux to the material surfaces in a tokamak

Kimura, Hiroyuki; Maeda, Hideaki; Ueda, N.; Seki, Masanori; Kawamura, Hiroshi; Yamamoto, Satoshi; Nagami, M.; Odajima, K.; Sengoku, S.; Shimomura, Y.

doi:10.1088/0029-5515/18/9/002

Cited by 41 publications

(32 citation statements)

References 9 publications

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“…In the next section four configurations are considered, starting with the one most easy to interpret followed by progressively less straightforward ones. Unfortunately most large-probe studies to date [2,[4][5][6][7][8][9][10]] have used the fourth and most problematical configuration. The configurations are shown in figure 3.…”

Section: Definition Of a Large Probementioning

confidence: 99%

Large probes in Tokamak scrape-off plasmas. The collisionless scrape-off layer: operation in the shadow of limiters or divertor plates

Stangeby¹

1985

J. Phys. D: Appl. Phys.

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With the exception of simple Langmuir probes, all other probes used to diagnose the scrape-off plasma behind the limiter radius of separatrix in Tokamaks are usually sufficiently large that they disturb the plasma they are measuring. An analysis procedure is outlined for recovering the undisturbed plasma parameters from those measured by a large probe in a collisionless scrape-off layer. The analysis is applied to experimental data recorded by large probes inserted into the scrape-off layer of the DITE Tokamak.

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Section: Definition Of a Large Probementioning

confidence: 99%

Large probes in Tokamak scrape-off plasmas. The collisionless scrape-off layer: operation in the shadow of limiters or divertor plates

Stangeby¹

1985

J. Phys. D: Appl. Phys.

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“…where Kj is the parallel electron heat conduction coefficient [11], B p /B T the pitch of the field line, S the cross-sectional area of divertor scrape-off, 7 the heat transmission coefficient (= 7.8), and T the particle flux (=0.3Csn e ) [12]. Figure 15 is a typical computational result showing the T e , n e , Pr DIV profiles along the field line for 1% oxygen level and POH~ Pr = 300 kW.…”

Section: Remote Radiative Coolingmentioning

confidence: 99%

Impurity reduction and remote radiative cooling with single-null poloidal divertor in Doublet-III

et al. 1982

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The successful operation of a single-null poloidal divertor in Doublet-Ill has demonstrated several new advantages of a diverted tokamak in addition to the suppression of impurity influx as demonstrated in DIVA: 1) The impurity contamination and radiation loss of the main plasma has been reduced by an open divertor geometry, i.e. without a divertor chamber; 2) The radiative cooling and formation of a dense and cold (n e >5Xl0 13 crn~3, T e <7 eV, P H , < 4 X 10' 3 torr) divertor plasma have been observed. -Up to 50% of the Ohmic input power is radiated in the divertor region, thus cooling the plasma in front of the divertor plate down to several eV. This remote radiative cooling greatly reduces the heat load on the divertor plate without cooling the main plasma. -The feasibility of remote radiative cooling in INTOR was studied by use of a volume integration technique of the radiation power along the field line.

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“…Also, in plasmas with continuous conducting walls, where local ambipolarity is not necessarily satisfied, SEE can modify current flows in the plasma. SEE plays an important role in a wide range of plasma devices and diagnostics, such as Hall thrusters [3], plasma processing devices [4], magnetic fusion experiments [5,6], and Langmuir probes [7].…”

Section: Introductionmentioning

confidence: 99%

Observation of reduction of secondary electron emission from helium ion impact due to plasma-generated nanostructured tungsten fuzz

Hollmann¹,

Doerner²,

Nishijima³

et al. 2017

J. Phys. D: Appl. Phys.

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Growth of nanostructured fuzz on a tungsten target in a helium plasma is found to cause a significant (~3×) reduction in ion impact secondary electron emission in a linear plasma device. The ion impact secondary electron emission is separated from the electron impact secondary electron emission by varying the target bias voltage and fitting to expected contributions from electron impact, both thermal and nonthermal; with the non-thermal electron contribution being modeled using MonteCarlo simulations. The observed (~3×) reduction is similar in magnitude to the (~2×) reduction observed in previous work for the effect of tungsten fuzz formation on secondary electron emission due to electron impact. It is hypothesized that the observed reduction results from re-absorption of secondary electrons in the tungsten fuzz.

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Heat flux to the material surfaces in a tokamak

Cited by 41 publications

References 9 publications

Large probes in Tokamak scrape-off plasmas. The collisionless scrape-off layer: operation in the shadow of limiters or divertor plates

Large probes in Tokamak scrape-off plasmas. The collisionless scrape-off layer: operation in the shadow of limiters or divertor plates

Impurity reduction and remote radiative cooling with single-null poloidal divertor in Doublet-III

Observation of reduction of secondary electron emission from helium ion impact due to plasma-generated nanostructured tungsten fuzz

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