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Eckstein, Peter P.; Götze, W.; Hartl, Friedrich; Rönz, Bernd; Strohe, Hans Gerhard

doi:10.1007/978-3-322-91144-5_23

Cited by 7 publications

(13 citation statements)

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“…The influence of deuterium trapped in carbon on the deuterium refiedion was studied with the Monte Carlo program TRIM.SP in the energy range from 20 eV to 2 keV [S] for a composition C0,7D0.J ( fig.2). The sum of sputtered and backscattered deuterium gives nearly the same value as the reflection coefficient from pure carbon, but the energy distribution of the sputtered deuterium is shifted to lower energies compared to the energy distribution of the backscattered particles [5].…”

Section: Hydrogen Partlcle Balancementioning

confidence: 89%

“…They should be compared with the results of computer simulation programs such as the WBC [23] and the ERO 124) code. Calculated particle reflection coefficient R, and hydrogen sputtering coefficient Y(H) for pun nickel and hydrogen containing nickel and for carbon targeu (program TRSPVMC) [5]. F i g 2 Energy distributions of backscattered and sputtered deuterium due to the bombardment of deuterium implanted carbon, (&Do.3.…”

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confidence: 99%

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Boundary Conditions at the Vessel Walls being in Contact with a Hot Plasma

Behrisch

Naujoks

1994

Contrib. Plasma Phys.

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The main atomic processes occuring at the solid wall during plasma wall interaction are presented. The data are based on experimental results obtained under laboratory and plasma conditions and/or by computer simulations.The particle and energy confinement for a plasma in a magnetic field is always limited due to drift-, diffusion-and radiation losses. For a burning fusion plasma the limited confinement is necessary for exhausting the energy from the fusion reactions and the helium ash. This is the source for plasma wall interactions, which cannot be avoided in a fusion reactor [I]. We rather have to learn to understand and to control them. Major processes in PSI are those determining the sheath potential, those determining the hydrogen particle balance and those causing erosion at the vessel walls and the introduction of wall atoms representing impuriiies in the plasma.The sheath potential between a plasma and the surface of a solid adjusts itself so as to reduce the electron flux to the surface until it is equal to the ion flux. The potential is reduced by electron emission from the surface caused by the electron and ion bombardment as well as by thermal emission [2].The average particle confinement time in today's plasma experiments is in the range of 1 ms to 1 s and thus short compared to the discharge time. Particles leaving the plasma impinge onto the vessel walls and during the discharge they are continuously introduced back into the plasma from the vessel walls. These mechanisms of particle recycling are a criiical issue for plasma density control. The plasma ions can be backscattered or they may be implanted and stopped in the wall material. If the surface layers of the vessel walls get saturated, hydrogen may be released as thermal molecules. At very high flux densities dynamical trapping was observed, i.e. hydrogen may be retained in the wall areas for a time of the order of the particle confinement time.

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Section: Hydrogen Partlcle Balancementioning

confidence: 89%

mentioning

confidence: 99%

Boundary Conditions at the Vessel Walls being in Contact with a Hot Plasma

Behrisch

Naujoks

1994

Contrib. Plasma Phys.

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“…The irradiation times of Figure 2(a-c) were 1, 3, and 10 h, respectively. [47] Thus, the difference in the sputtering yield could have led to the difference in the morphology changes (nanocones for Ti and FNs for Nb). Also, the difference in the ion flux by~20 % (2:4 À 3:1 Â 10 22 m À2 ) had a minor effect, considering the fact the irradiationtime was changed by a factor of three or greater.…”

Section: Morphology Changesmentioning

confidence: 99%

“…In the energy range of 70-100 eV, the 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 sputtering yield of Nb by He bombardment is 2-4 10 À3 , [46] which is one order of magnitude less than that for Ti. [47] Thus, the difference in the sputtering yield could have led to the difference in the morphology changes (nanocones for Ti and FNs for Nb). Figure 3(d) shows a color mapping of Nb (green) and oxygen (red) of the structure shown in Figure 3(c).…”

Section: Morphology Changesmentioning

confidence: 99%

One‐Step Plasma Synthesis of Nb₂O₅ Nanofibers and their Enhanced Photocatalytic activity

et al. 2018

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Fiberform nanostructured niobium (Nb) was fabricated by one step helium (He) plasma irradiation. He ion implantation formed He nano-bubbles on a Nb plate and led to formation of protrusions while migrating in Nb matrix; fiberform nanostructures (FN) were grown when the fluence became high (> 10 26 m À2 ). The necessary conditions for the formation of Nb FN were revealed to be the surface temperature range of 900-1100 K and the incident ion energy higher than 70 eV. The sample was oxidized at 573-773 K in an air atmosphere, and Pt nanoparticles were photo-deposited on the Nb 2 O 5 samples. The surface was analyzed by scanning electron microscope, transmission electron microscope, x-ray photoelectron spectroscopy, and ultraviolet-visible spectrophotometry. Photocatalytic activity of the fabricated materials was studied using methylene blue (MB) decolorization process. An enhanced photocatalytic performance was identified on FN Nb 2 O 5 substrate with Pt deposition.[a] Dr.

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“…This interpretation, however, does not account for all observed ∆δ and ∆ν values, and especially not for the divergences within the series of compounds 1. To our surprise, a recent X-ray study of a similar xanthine derivative 7 [11] showed linear strands with consecutive xanthine and Rh* molecules where one Rh* entity complexes to a C-2 carbonyl group on each side, whereas the next Rh* complexes to two C-6 carbonyls (Scheme 6). [12] It thus follows that there is an equilibrium between kinetically unstable complexes with different binding sites in solution.…”

Section: Binding Sites and Binding Modementioning

confidence: 99%

Chiral Discrimination of Some Annelated Xanthine Derivatives by the Dirhodium Method

Rockitt¹,

Duddeck²,

Drabczyńska³

et al. 2000

Eur. J. Org. Chem.

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Complete 1 H and 13 C signal assignments and conformation analyses of the title compounds (racemic mixtures) were performed. Most 1 H and 13 C NMR signals were resolved in the presence of the enantiomerically pure dirhodium complex Rh 2 (MTPA) 4 (Rh*) allowing for clear and simple chiral recognition. A detailed interpretation of the signal shifts (∆δ) and dispersions (∆ν) in the diastereomeric complexes suggested that the π-system around the C-4/C-5 bond of the central im- [a] Universität Hannover,

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W

Cited by 7 publications

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Boundary Conditions at the Vessel Walls being in Contact with a Hot Plasma

Boundary Conditions at the Vessel Walls being in Contact with a Hot Plasma

One‐Step Plasma Synthesis of Nb₂O₅ Nanofibers and their Enhanced Photocatalytic activity

Chiral Discrimination of Some Annelated Xanthine Derivatives by the Dirhodium Method

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Cited by 7 publications

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Boundary Conditions at the Vessel Walls being in Contact with a Hot Plasma

Boundary Conditions at the Vessel Walls being in Contact with a Hot Plasma

One‐Step Plasma Synthesis of Nb2O5 Nanofibers and their Enhanced Photocatalytic activity

Chiral Discrimination of Some Annelated Xanthine Derivatives by the Dirhodium Method

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One‐Step Plasma Synthesis of Nb₂O₅ Nanofibers and their Enhanced Photocatalytic activity