Increased recombination of CH3 radicals on stainless steel

被引：10

作者：

Gorodetsky, AE

Zalavutdinov, RK

Zakharov, AP

Vnukov, SP

Varshavskaya, IG

Makhankov, AN

Mazul, IV

Federici, G

机构：

[1] Russian Acad Sci, Inst Chem Phys, Moscow 119991, Russia

[2] Efremov Inst, St Petersburg 196641, Russia

[3] ITER Garching Joint Work Site, D-85748 Garching, Germany

来源：

JOURNAL OF NUCLEAR MATERIALS | 2005年 / 337卷 / 1-3期

关键词：

erosion and deposition; impurity transport; neutrals; recombination;

D O I：

10.1016/j.jnucmat.2004.10.133

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

By using a so-called 'stream technique', which consists of flowing gas in laminar regime along a quartz tube, we determine that CH3 radicals are completely removed from the pumped mixture (CH4/CHXHY/H-2/CH3) after several hundred collisions with the inner surface of a stainless steel insert (T = 380-470 K). The methyl sticking coefficient decreased to similar to 10(-6) and the recombination coefficient increased up to similar to 0.01 at impingement with the metal surface. After passing through the heated zone no hydrocarbon deposition occurred at 300 K. However, unsaturated hydrocarbons, which formed in discharge zone and appeared as a result of interaction of radicals with stainless steel, condensed in a liquid phase at a temperature of similar to 130 K and partial pressure of 0.0-0.1 Pa. Liquid films underwent partial polymerization and formed island deposits, which were stable at 300 K. (c) 2004 Elsevier B.V. All rights reserved.

引用

收藏

页码：892 / 896

页数：5

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