In a conventional diffractometer defocussing and flat specimen error can be convoluted together independently, but this is no longer valid in a LPSD system.
22 for profile arising from a central ray entering the LPSD at 0.
When a diffracted x-ray photon enters a LPSD its path in the detector gas is not perpendicular to the anode wire, except at the centre of the detector, and additional broadening, known as parallax broadening, is introduced into off-centre diffraction lines.
mu] PSD]([epsilon]) at an angle [beta] to the centre of the LPSD is given by,
The ultimate resolution of a LPSD is the spatial uncertainty of the position measurement of an individual x-ray photon incident normal to the anode wire of the detector.
040 mm are possible when the gas in the LPSD is under pressure.