Analysis of Laue data and wavelength normalisation

The wavelength normalisation problem was introduced in section 7.1.2. The measured intensity of a single Laue spot or of an energy deconvoluted spot needs correction or normalisation for a variety of wavelength-dependent factors if data are to be obtained comparable to monochromatic data. The wavelength at which a reflection is stimulated affects the measured spot intensity through a variety of processes  

The calculated spectrum (see chapter 4) is modified at the long wavelength end by absorption due to beam line windows or any airpaths in the Laue camera. Also, the short wavelengths are cut off if a reflecting mirror is used (and this may be the case for focussing or to aid more precise definition of spot multiplicity). 

In addition, there is the Lorentz factor (sin2 0)1 (Zachariasen 1945 Buras and Gerward 1975 Kalman 1979). 

The recorded Laue intensity (strictly, an integrated power) is given for the reflection hk (abbreviated to the symbol h) by (Campbell et al (1986) and references cited therein) 

d//dA denotes the spectral intensity distribution of the incident X-ray beam V is the volume of sample illuminated V0 is the sample unit cell volume 0 is the Bragg angle for the reflection h P is the polarisation factor A is an absorption correction for the sample in its capillaiy and D is a detector sensitivity and obliquity factor. Quantities such as P, A and D vary with any or all of A, 0 and x, the position of the diffracted beam on the detector the spectral intensity distribution is, in general, not precisely known in advance and the detector may suffer from spatial distortion and non-uniformity. Thus equation (7.17) may be written as 

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