To standardise and simplify the analysis of reflectivity data the software code SURFace has been developed at ISIS. The SURFace code is able to simulate and fit data using an intuitive and easy-to-use graphical interface. In such an environment the user is free to vary any of the parameters through sliders and text input boxes and immediately see the effect on the calculated reflectivity profile. The data input is based around easily transportable ASCII files
The SURFace code is ideally suited to simulating many of the experimental geometries measured on the SURF and CRISP reflectometers at ISIS, for example solid-liquid interfaces, solid air etc.. In addition data can be fitted using a SIMPLEX algorithm developed by D.S. Sivia (ISIS). The code is freely available and can be installed easily on a PC platform running Windows95/WindowsNT. Given the development status of the code comments on possible improvements and software faults are most welcome. Current projects include an interface for multi-layer samples and an analysis suite for polarised neutron reflectivity data. For any further questions or comments and information on how to obtain the software please contact John Webster (extension 63181, firstname.lastname@example.org) or Sean Langridge (extension 5269, email@example.com).
Screen shot 1 - A typical view of SURFace showing the observed reflectivity from D2O on a Si substrate (green line) and the fitted profile (blue line). The associated fitted parameters are displayed in Form2. The resultant scattering length density is also shown.
Screen shot 2- The same data as in screen shot 1, but displayed in Genie. Running on the Surf alpha workstation. As evidenced numerous fitting algorithms are available.
Screen shot 3 - The simulated reflectivity of a single layer with a 5Å rms roughness. The slider allows one to change (in this example) the scattering length density of the layer and to display the resultant profile. The simulation is displayed as a Guinier plot.
Screen shot 4 - A simulation plotted as the RQ^4. in this example the slider allows one to change the roughness of the selected interface