عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Tokamak divertor plasma is characterized by variety of plasma parameters such as plasma density and temperature, as well as plasma composition and overcoming plasma dynamics processes. A model was surveyed for theoretical study of the interaction of hydrogen with dust surface and the results is applied to the formation of H2 molecule on the dust grain surfaces in the tokamak divertor plasma. In this model, by considering both physisorbed and chemisorbed sites on the grain surface, the adatoms on the surface migrate from one adsorb site to other adsorb site by thermal diffusion and form H2 on the dust grain surfaces. The H2 formation rate on the high temperature dust surfaces in the divertor plasma region has been found for a range of gas temperatures and densities.
 J. Kuppers, The hydrogen surface chemistry of carbonas a plasma facing material, Surf. Sci. Rep. 22 (1995) 249.
 V. Philipps, J. Roth, A. Loarte, Key issues in plasma–wall interactions for ITER: a European approach, Plasma Phys. Cont. Fusion, 45 (2003) A17.
 S.I. Krasheninnikov, A.Yu. Pigarov, R.D. Smirnov, T.K. Soboleva, Theoretical aspects of dust in fusion devices, Contrib. Plasma Phys, 50 (2010) 410-425.
 X. Sha, B. Jackson, D. Lemoine, Quantum studies of eley-rideal reactions between H atoms on a graphite surface, J. Chem. Phys, 116 (2002) 7158.
 T. Zecho, A. Guettler, X. Sha, B. Jackson, J. Kueppers, Abstraction of D chemisorbed on graphite (0001) with gaseous H atoms, Chem. Phys. Lett, 366 (2002) 188-195.
 A.Yu. Pigarov, S.I. Krasheninnikov, Modeling of dust- particle behavior for different materials in plasmas, Phys. Plasmas, 14 (2007) 052504.
 L. Hornekuer, E. Rauls, W. Xu, Z. Sljivancanin, R. Otero, I. Steensgaard, E. Luegsgaard, B. Hammer, F. Besenbacher, Clustering of chemisorbed H(D) atoms on the graphite (0001) surface due to preferential sticking, Phys. Rev. Lett, 97 (2006) 186102.
 L. Hornekuer, Z. Sljivancanin, W. Xu, R. Otero, E. Rauls, I. Steensgaard, B. Hammer, F. Besenbacher, Metastable structures and recombination pathways for atomic hydrogen on the graphite (0001) surface, Phys. Rev. Lett, 96 (2006) 156104.
 L. Jeloaica, V. Sidis, DFT investigation of the adsorption of atomic hydrogen on a cluster-model graphite surface, Chem. Phys. Lett, 300 (1999) 157-162.
 Y. Ferro, F. Marinelli, A. Allouche, C. Brosset, Density functional theory investigation of H adsorption on the basal plane of boron-doped graphite, J. Chem. Phys, 118 (2002) 8124.
 A. Messiah, Quantum mechanics, Amsterdam: North-Holland (1961).
 S. Cazaux, A.G. Tielens, ERRATUM: H2 formation on grain surfaces, ApJ, 604 (2004) 222.
 C. Thomas, T. Angot, J. Layet, Investigation of D (H) abstraction by means of high resolution electron energy loss spectroscopy, Surf. Sci, 602 (2008) 2311-2314.
 S. Morisset, F. Aguillon, M. Sizun, V. Sidis, Wave-packet study of H2 formation on a graphite surface through the Langmuir-Hinshelwood mechanism, J. Chem. Phys, 15 (2005) 194702.
 N. Ohno, N. Ezumi, S. Takamura, S.I. Rasheninnikov, A.Yu. Pigarov, Experimental evidence of molecular activated recombination in detached recombining plasmas, Phy. Rev. Lett, 81 (1998) 818-821.
 J. Winter, Dust in fusion devices-a multi-faceted problem connecting high- and low-temperature plasma physics, Plasma Phys. Control. Fusion, 46 (2004) B583.