Quantitative characterization of a highly effective atomic hydrogen doser

被引:69
作者
Eibl, C [1 ]
Lackner, G [1 ]
Winkler, A [1 ]
机构
[1] Graz Tech Univ, Inst Festkorperphys, A-8010 Graz, Austria
来源
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS | 1998年 / 16卷 / 05期
关键词
D O I
10.1116/1.581449
中图分类号
TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
An atomic hydrogen doser of the Bertel type was characterized in terms of the degree of dissociation and angular distribution of the effusing particles. In this doser hydrogen is dissociated in a tungsten tube which is heated by electron bombardment. Various experimental techniques were used to determine the degree of dissociation as function of temperature and gas flux. It is shown that simple equilibrium considerations cannot be applied to obtain the degree of dissociation accurately. Nevertheless, for sufficiently small gas flux and temperatures above 1850 K, the degree of dissociation approaches 100%. The angular distribution was determined by a gold foil on a goniometer as detector, which is sensitive to atomic hydrogen only.:The experimental results were compared with Monte Carlo simulations. A strongly forward focused distribution is observed which allows efficient atomic hydrogen dosing. This doser was used to measure absolute initial sticking coefficients for atomic hydrogen on various single crystal metal surfaces: S-0(H) = 1.0 on Ni(111), 0.9 on Ni(110), 0.7 on Al(111), 0.6 on Al(100) and 0.5 on a polycrystalline gold foil, respectively. (C) 1998 American Vacuum Society. [S0734-2101(98)04405-4].
引用
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页码:2979 / 2989
页数:11
相关论文
共 29 条
[1]  
Barin I.P.D., 1989, Thermochemical Data of Pure Substances
[2]   AN INVESTIGATION OF VIBRATIONALLY ASSISTED ADSORPTION - THE CASES H-2/CU(110) AND H-2/AL(110) [J].
BERGER, HF ;
RENDULIC, KD .
SURFACE SCIENCE, 1991, 253 (1-3) :325-333
[3]  
BERGMANN L, 1987, LEHRBUCH EXPT PHYSIK, V3
[4]   SIMPLE SOURCE OF ATOMIC-HYDROGEN FOR ULTRAHIGH-VACUUM APPLICATIONS [J].
BISCHLER, U ;
BERTEL, E .
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS, 1993, 11 (02) :458-460
[5]   STICKING, ADSORPTION, AND ABSORPTION OF ATOMIC-H ON CU(110) [J].
BISCHLER, U ;
SANDL, P ;
BERTEL, E ;
BRUNNER, T ;
BRENIG, W .
PHYSICAL REVIEW LETTERS, 1993, 70 (23) :3603-3606
[6]   Adsorption and abstraction of atomic hydrogen (deuterium) on Al(100) [J].
Boh, J ;
Eilmsteiner, G ;
Rendulic, KD ;
Winkler, A .
SURFACE SCIENCE, 1998, 395 (01) :98-110
[7]   2-PHOTON EXCITATION OF THE N = 3 LEVEL IN H-ATOM AND D-ATOM [J].
BOKOR, J ;
FREEMAN, RR ;
WHITE, JC ;
STORZ, RH .
PHYSICAL REVIEW A, 1981, 24 (01) :612-614
[8]   INTERACTION OF HYDROGEN WITH SOLID-SURFACES [J].
CHRISTMANN, K .
SURFACE SCIENCE REPORTS, 1988, 9 (1-3) :1-163
[9]   The beam shaping in the molecular flow. [J].
Clausing, P. .
ZEITSCHRIFT FUR PHYSIK, 1930, 66 (7-8) :471-476
[10]  
DANIELS F, 1956, PHYSICAL CHEM