Input: Experimental conditions

Besides the variation of the structure data, also the conditions for the simulation of the diffraction patterns may be changed very user-friendly. Therefore, in PowderCell a special screen has been created where only these data will be presented which are related with the experimental conditions:

radiation (i.e. X-rays or neutrons)
anode material (i.e. wavelength)
consideration of anomaleous dispersion
K_a₁/ K_a₂ doublet (L_a₁/ L_a₂ for W)
diffraction geometry
variable or fixed slit system
2q range and step width

For the X-radiation the following anode materials has been implemented: Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ag and W. Only for that the corresponding corrections (penetration depth, mass attenuation, anomaleous dispersion) may be considered during the powder pattern calculation. This is important e.g. for the quantitative phase analysis.

The resulting powder patterns also depend on the used diffraction geometry. PowderCell considers the Bragg-Brentano arrangement but also the Guinier geometry. There the use of a {011}-quartz-monochromator is assumed. How one can change the monochromator characteristic (diffraction angle etc.) will be given in the detailed help of the program.

Federal Institute for Materials Research and Testing
Unter den Eichen 87, D-12205 Berlin,
Germany