Description

This tool enables X-ray users to calculate the slit size (FWHM/2) for resolution smearing purposes based on their half beam profile data (as Q vs Intensity; any other data fields are ignored).

Method

The tool works by sequentially summing 10 or more intensity values until a maximum value is attained. It then locates the Q values for the points just before, and just after, half of this maximum value and interpolates between them to get an accurate value for the Q value for the half maximum.

NOTE! Whilst it may have some more generic applicability, the calculator has only been tested with beam profile data from Anton-Paar SAXSess^TM software. The beam profile file does not carry any information about the units of the Q data. It is probably |nm^-1| but the resolution calculations assume the slit height/width has units of |Ang^-1|. If the beam profile data is not in these units then it, or the result, must be manually converted.

Using the tool

1. Select Slit Size Calculator from the Tool menu on the SasView toolbar.

2. Load a beam profile file in the Data field using the Browse button.

   NOTE! To see an example of the beam profile file format, visit the file beam profile.DAT in your {installation_directory}/SasView/test_1d folder.

3. Once a data is loaded, the slit size is automatically computed and displayed in the tool window.