Expected values and variances of Bragg peak intensities measured in a nanocrystalline powder diffraction experiment
نویسندگان
چکیده
منابع مشابه
Powder diffraction in Bragg–Brentano geometry with straight linear detectors
A common way of speeding up powder diffraction measurements is the use of one- or two-dimensional detectors. This usually goes hand in hand with worse resolution and asymmetric peak profiles. In this work the influence of a straight linear detector on the resolution function in the Bragg-Brentano focusing geometry is discussed. Because of the straight nature of most modern detectors geometrical...
متن کاملPhenomenological model of anisotropic peak broadening in powder diffraction
Anisotropic line-shape broadening (peak width which is not a smooth function of d-spacing) is frequently observed in powder diffraction patterns, and can be a source of considerable dif®culty for whole-pattern ®tting or Rietveld analysis. A model of the multi-dimensional distribution of lattice metrics within a powder sample is developed, leading naturally to a few parameters which can be varie...
متن کاملA new model for Spread Out Bragg Peak in proton therapy of uveal melanoma
In this research, in order to improve our calculations in treatment planning for proton radiotherapy of ocular melanoma, we improved our human eye phantom planning system in GEANT4 toolkit. Different analytical models have investigated the creating of Spread Out Bragg Peak (SOBP) in the tumor area. Bortfeld’s model is one of the most important analytical methods. Using convolution method, a new...
متن کاملOn the equivalence of the Rietveld method and the correlated integrated intensities method in powder diffraction
The Rietveld method is the most straightforward and statistically correct approach for the re®nement of crystal structure parameters from powder diffraction data. The equivalent two-stage approach, involving the re®nement of structural parameters based on integrated intensities extracted using the Pawley method, is extremely useful in circumstances such as the global optimization methods of str...
متن کاملElectron Ionization of Serine and Threonine: a Discussion about Peak Intensities
The present study describes the fragmentation under electron ionization (EI) of gas phase serine and threonine amino acids. Ab initio methods were performed to calculate the fragmentation paths and interpret the mass spectra. The six lowest energy conformers of L-serine, L-threonine and L-allo-threonine were obtained with B3LYP, G3MP2 and MP2 methods. The adiabatic and vertical ionizat...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Applied Crystallography
سال: 2017
ISSN: 1600-5767
DOI: 10.1107/s1600576717010494