Increased recombination of CH3 radicals on stainless steel

Gorodetsky, А.Е.; Залавутдинов, Р. Х.; Захаров, А.П.; Vnukov, S. P.; Varshavskaya, I.G.; Makhankov, A.; Mazul, I.; Federici, G.

doi:10.1016/j.jnucmat.2004.10.133

Cited by 14 publications

(9 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…По достижении определённой температуры скорость травления увеличивается настолько, что может полностью подавить осаждение [17,18]. Таким образом, для каждого состава газовой смеси можно, экстраполировав экспериментальные данные с помощью ли-нейной зависимости до пересечения с осью температур, определить температуру, при которой плёнка имеет скорость роста, равную нулю (так называемая «нулевая скорость роста»).…”

Section: результаты и обсуждениеunclassified

Experimental Study of Hydrocarbon Film Deposition on Metallic Mirrors

Vukolov¹,

Mukhammedzyanov²,

Zvonkov³

et al. 2010

PAST-TF

View full text Add to dashboard Cite

Section: результаты и обсуждениеunclassified

Experimental Study of Hydrocarbon Film Deposition on Metallic Mirrors

Vukolov¹,

Mukhammedzyanov²,

Zvonkov³

et al. 2010

PAST-TF

View full text Add to dashboard Cite

“…To study the processes of transport, condensation and recombination of hydrocarbon radicals, a cylindrical quartz tube of radius R = 1 cm and length l = 100 cm was used [1,2].…”

Section: Experimental Techniquementioning

confidence: 99%

“…In experiments with pure methane, the approximate composition of mixture flowing out of the RF discharge was as follows: CH 4 , 80 × 10 14 cm −3 ; CH 3 , 0.2 × 10 14 cm −3 ; H 2 , (1−10) × 10 14 cm −3 ; H, 0.03 × 10 14 cm −3 ; C 2 H x , 2 × 10 14 cm −3 ; C 3 H y , 0.3 × 10 14 cm −3 [2]. The total concentration of new hydrocarbons and molecular hydrogen was 4-10% from the methane concentration.…”

Section: Experimental Techniquementioning

confidence: 99%

“…The value n was measured in experiments on the condensation of radicals at liquid-nitrogen temperature [2,14].…”

Section: Deposition and Formation Of New Hydrocarbon Species Under Comentioning

confidence: 99%

“…Behind the grid, in the afterglow region, the neutralized activated mixture consisted of a series of light hydrocarbons, molecules and atomic hydrogen. The analysis of the experimental data on the hydrocarbon film deposition [1,2] has shown that the main chemically active particles in such a mixture are methyl (CH 3 ) radicals and atomic hydrogen. The activated mixture passed through a tungsten insert located downstream of the flow approximately in the tube centre.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Methyl radical chemical reactions on a tungsten surface

Gorodetsky

Залавутдинов

Vnukov

et al. 2008

Plasma Devices and Operations

View full text Add to dashboard Cite

In this paper an interaction of the inner dome surfaces of the International Thermonuclear Experimental Reactor with a gas mixture containing hydrocarbon radicals has been modelled. To study the processes of transport and deposition of methyl radicals in a C x H y -H 2 -H (x = 1−3, y = 1−6) flow, a stream technique has been used. A radiofrequency inductive discharge initiated in methane at the inlet of a quartz tube was a source of methyl and hydrogen atoms. Methyl radicals were transported by a gas flow that passed through cylindrical tungsten inserts and were deposited on the tube wall, on silicon samples and on tungsten samples, forming polymer-like hydrogenated amorphous carbon films. It has been shown that at the tungsten insert temperature increases to 420 K, and carbon deposition rate decreased significantly. However, in the gaseous phase the secondary hydrocarbon species accumulated and condensed on the tungsten surface at a temperature lower than 340 K.

show abstract

Surface effects on the diagnostic of carbon/nitrogen low‐pressure plasmas studied by differentially pumped mass spectrometry

2014

View full text Add to dashboard Cite

In this work, the characterization of the species produced in reactive plasmas by differentially pumped mass spectrometry is addressed. A H2/CH4/N2 mixture (90 : 5 : 5) was fed into a direct current glow discharge and analysed by conventional and cryo-trap assisted mass spectrometry. The gaseous mixture was chosen because of its particular relevance in the inhibition of tritium-rich carbon film deposition in fusion plasmas (scavenger technique) and in the deposition of amorphous hydrogenated carbon films by plasma-assisted chemical vapour deposition. Important changes in the composition of the detected species upon surface modification of the reactor walls (stainless steel or covered by an amorphous hydrogenated carbon layer) or in the way they are sampled (length and spatial configuration of the stainless steel duct) were detected. They are analysed in terms of radical formation and recombination on the reactor walls or into the sampling duct, thus providing some insight into the underlying chemistry. In general, when the reactor walls are covered by an amorphous hydrogenated carbon layer, more hydrocarbons are produced, but the radical production is lower and seem to be less reactive than in stainless steel. Also, two sources of oxygen contamination in the plasma have been identified, from the native oxide layer in stainless steel and from unintended water contamination in the chamber, which modify considerably the detected species.

show abstract

Increased recombination of CH3 radicals on stainless steel

Cited by 14 publications

References 10 publications

Experimental Study of Hydrocarbon Film Deposition on Metallic Mirrors

Experimental Study of Hydrocarbon Film Deposition on Metallic Mirrors

Methyl radical chemical reactions on a tungsten surface

Surface effects on the diagnostic of carbon/nitrogen low‐pressure plasmas studied by differentially pumped mass spectrometry

Contact Info

Product

Resources

About