Loading “Dayta” System Files (University of Bristol Interface Analysis Centre)

Spectra acquired by the Bristol “Dayta” system are stored as sets of ACSII files with .SP_ file extensions. These files may be connected to a particular experiment through an associated .seq file. Sets of .SP_ spectrum files are listed in the .seq file together with the any experimental information (e.g. etch times.)

There are two methods for loading Bristol files.

• The simplest method is to convert files that are listed in a .seq file. All that is required is for the .seq file and all the .SP_ files listed within that file are located in the same sub-directory, then the .seq file is selected through the “Convert to VAMAS file” dialog window. If for any reason the set of .SP_ files does not match the set listed in the .seq file, then the .seq will need to be edited to remove or add entries as necessary. The VAMAS file that results will include an experimental variable for each spectrum loaded.

• The alternative method for loading the .SP_ files is to collect a set of these files in a sub-directory and then enter a new filename in the “Convert to VAMAS file” dialog window, but add an extension of .bri to the specified name (Figure 1). All .SP_ files in the directory will be read and appear in a single VAMAS file. The default action is that no experimental variable it defined for each spectrum. As a consequence spectra read will all appear in the same row in CasaXPS (i.e. in a format suitable for quantification of high resolution spectra). If on the other hand it would be more convenient to separate spectra by an experimental variable then the new file name entered in the dialog window should be followed by a –col string e.g. “newfile.bri –col” (omit the quotation marks). The experimental variable is the index number determined form the order in which the files are read.

Figure 1: Convert to VAMAS file dialog window, where a .bri file extension has been specified. The result is a file called newfile.vms containing all the .SP_ data files seen in the window.