Digitale Medien
Copenhagen
:
International Union of Crystallography (IUCr)
Applied crystallography online
21 (1988), S. 818-822
ISSN:
1600-5767
Quelle:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Thema:
Geologie und Paläontologie
,
Physik
Notizen:
Small-angle scattering measurements from protonated polystyrene (PSH) and mixtures of deuterated and protonated toluene (C7D8 and C7H8) are presented. The data are compared with the simple `quasi-isotropic' Vineyard model, corrected for third- and higher-order multiple scattering by Monte Carlo methods. This model agrees surprisingly well with all protonated samples over the total thickness range considered. The empirical Jacrot g factor in the expression I(Q) = K(1 − T)g(λ)/4π works well over a more limited thickness range. The effective differential cross section can be calculated using Melkonian total cross sections, and this gives an absolute scattered intensity which is 9% lower than a calibration performed at Oak Ridge National Laboratory. Scattering from oversize samples must be back shielded. The model requires an anisotropic kernel to predict D/H toluene mixtures.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1107/S0021889888004078
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