Influence of molecular clustering on the interpretation of diffractograms of hydrocarbon films from tokamak T-10

Journal Article · Tue Dec 15 00:00:00 EST 2015 · Physics of Atomic Nuclei

DOI:https://doi.org/10.1134/S1063778815100075· OSTI ID:22471975

Neverov, V. S., E-mail: [e-mail] ^[1]; Voloshinov, V. V., E-mail: [e-mail] ^[2]; Kukushkin, A. B., E-mail: [e-mail] ^[1]; Tarasov, A. S., E-mail: [e-mail] ^[2]

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1. National Research Center Kurchatov Institute, Tokamak Physics Institute (Russian Federation)
2. Russian Academy of Science, Institute for Information Transmission Problems (Kharkevich Institute) (Russian Federation)

The influence of molecular clustering on the formerly suggested interpretation of diffraction patterns of hydrocarbon films formed in the vacuum vessel of the tokamak T-10 is analyzed numerically. The simulation of clustering of simple hydrocarbon molecules C(D, H){sub 4}, C{sub 2}(D, H){sub 4}, and C{sub 6}(D, H){sub 6} and molecules composed of curved graphene (fullerenes and toroidal nanotubes) is carried out with the rigid body molecular dynamics method. It is shown that formerly neglected atomic correlations C–C and C–D(H) in the amorphous hydrocarbon component decrease the calculated values of the scattered intensity in the range of scattering vector modulus 5 < q < 20 nm{sup –1} because of homogenization of scatters on the spatial scale of ∼1 nm. The allowance for these correlations does not change the diffraction patterns in the range q > 20 nm{sup –1}. The results suggest the necessity to introduce to the procedure of determining the structural content of the films, similar to those from the tokamak T-10, the clusters formed by the van der Waals adhesion of hydrocarbon molecules to “graphene” nanoparticles. This simplifies the mathematical optimization to the former level of complexity—but for an extended ensemble of objects—and makes it possible to calculate the diffraction patterns of these objects using the distributed computing resources. A modified algorithm of structural content identification on the basis of joint X-ray and neutron diffractometry is suggested.

• OSTI ID: 22471975
• Journal Information: Physics of Atomic Nuclei, Vol. 78, Issue 10; Other Information: Copyright (c) 2015 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7788
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ADHESION
ALGORITHMS
COMPUTERIZED SIMULATION
CORRELATIONS
FILMS
FULLERENES
GRAPHENE
HYDROCARBONS
MOLECULAR DYNAMICS METHOD
MOLECULES
NANOPARTICLES
NANOTUBES
NEUTRON DIFFRACTION
PLASMA SIMULATION
T-10 TOKAMAK
VAN DER WAALS FORCES
X RADIATION
X-RAY DIFFRACTION