Reading I16 Data Files

Every time a scan command is started in GDA, a file is written to the experiment directory:

>>> scan eta 0.05 31 pil 1

File created in:

$ /dls/i16/data/20##/mm12345-1/SCANFILE

Currently, two types of file are created:

• DAT file "12345.dat": ASCII format file, readable in a text editor, contains columns of scan data and limited metadata, detector images stored in separate folder.

• Nexus file "12345.nxs": HDF format file, readable using hdf readers. Contains hierarchy of data structures including full instrument description, all scanned axes and links to detector images.

Detector images are stored separately in a folder created for each scan:

$ /dls/i16/data/20##/mm12345-1/12345-pilatus3_100k-files/00001.tif

Some detectors also store data as HDF files:

$ /dls/i16/data/20##/mm12345-1/12345-pilatus3_100k-files/12345.hdf

The tif image files are 32bit uncompressed images, it is also possible to save cbf images.

Example Dat File

Example Nexus file

Software to read Scan files

If you have any comments, suggestions or corrections, please contact a member of the beamline staff.