Guide to processed data for CH4 =============================== Data format =========== 3 columns of ASCII numbers. Comments start with "'" character (used by the Topas package). Data contents ============= Column 1: 2 theta angle Column 2: intensity Column 3: standard uncertainty in intensity File naming =========== The 8K file is named WBT0064309_CH4_.xye_filtered.xye The variable temperature files are named , where nnnn is the frame number counting from 0. So, for example, WBT0064309_CH4_0002.xye_filtered.xye is CH4 at 14K. Using the data ============== Data can be read into any common powder diffraction analysis software. The comment character may need to be changed. Deriving this data from the raw data ==================================== These datasets were derived from the raw data as follows: 1. Each frame was normalised to a common incident intensity using beam monitor counts for Monitor 2 found in the raw file. 2. Each frame was corrected for variable pixel gain by multiplying by a correction map. The correction map is in the HDF5 file vcal_241_sx_2017_10_10.gumtree.hdf at /entry1/data/signal with variance /entry1/data/variance. 3. Each frame was then summed in the vertical direction to yield a single value for each 2 theta value, ignoring the top and bottom 20 pixels. 4. A Fourier filter was applied to remove high-frequency components in the data, as per supplied Jupyter notebook Julia code (FFT-Wombat.ipynb). In the case of the 8K data, 3 frames were collected at the same temperature. These frames were summed together before performing step (3). Steps 1-3 were carried out using the Wombat Gumtree data reduction code. Please refer to https://github.com/Gumtree/Wombat_scripts/tree/18fd369e543a80650bb8a519f9c82e3b29a7c9a2/ExperimentScript/python/Reduction for the code used.