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Reflectometer D17

D17 is the first ILL dedicated reflectometer and it has been designed to be as flexible as possible in resolution and modes of operation. The instrument is suitable for the analysis of surface structures in solids and solid/liquid interfaces. Horizontal surface experiments, such as free liquids, will suffer from a severe restriction in Q-range and flux and are thus not recommended for this instrument.

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D17 LAMP Book

Depending on the type of grouping that is selected, COSMOS will output up to three output files for each of the reflectivity profile that it calculates.  The output files are all in ASCII.

The names of the files are identical, with different extensions.  You may choose the names of the files using the Out file column in the Data Table.  If this is not defined, the names of the files will be the number of the first run at the first angle.





The three types of file are:

*.out  

An output file with this extension is always returned by COSMOS.

This is an ASCII file that contains relevant information about the calculation and returns the unbinned data, along with the estimates for the q-resolution at each point.


The file has 22 lines of header information before the data begins.  The header summarizes the run numbers and calculation conditions for COSMOS. 

The 22nd line has the labels for the data columns.


The data are in 4 columns, which are (in order): scattering vector (in Å–1); reflectivity; error; resolution (in Å–1).

The format of each row is:

<number> <blank>  < number> <blank>  < number> <blank>  <number>

where each number occupies 13 characters.


The number of rows in the data depend on the number of time-of-flight channels used and the calculation parameters using in COSMOS.


You can find an example of a *.out file here.

 

*.dat

This is an ASCII file with 3 columns of data and no header.  The columns contain (from left to right) the values of Q (in Å–1), reflectivity and the error respectively.

This data file may be directly loaded in to the PARRATT32 reflectivity program.

You can find an example of a *.dat file here.

*.aft

This is an ASCII file with a four line header and 3 columns of data.  The columns contain (from left to right) the values of Q (in Å–1), reflectivity and the error respectively.

This data file may be directly loaded in to the AFIT reflectivity program.

You can find an example of a *.aft file here.