Lamp (large array manipulation program) allows you to visualise ILL data files as well as other types, like for example inx files. It is based on the idl package (interactive data language). Lamp is a multi-purpose program and can be used for data treatment by using macros written in idl, Fortran or C. See the LAMP BOOK.

Nplot/Plotmultiple (Matlab)

Matlab routines for treatment of Data from triple axis spectrometers (single detector and Flatcone).
(nplot, plotmultiple, etc.)
Instructions: download and copy in a directory of your choice. Then make sure that this directory is included in your Matlab PATH settings.
Author: Paul Steffens
Your questions and suggestions are welcome to steffens(at)

Nplot/Plotmultiple (Matlab)

PkFit, Filing

PkFit - a user friendly software for MacOS, OpenVMS and UNIX computers - is intended for the data processing of neutron Three-Axis Spectrometers (TAS). Inelastic, quasi-elastic or elastic spectra are fitted by a linear background plus a series of peak functions. The program offers several build-in peak functions but the user may add its own peak shapes through plug-in routines. The model can include the Bose factor, the kf or ki correction, the neutron absorption and the convolution of the signal with a one-dimensional or a four-dimensional resolution function. The later is calculated from the configuration parameters of the spectrometer through the help of the Cooper-Nathans method [3] or the Popovici method [4]. Fast 4D integration is performed by means of new methods, one based on a Monte-Carlo integration technique and the other based on a Gaussian approximation.

Filing - a user friendly software for MacOS, OpenVMS and UNIX computers - is intended for the data file handling of neutron Three-Axis Spectrometers (TAS).


Restrax is a tool for simulating the neutron optics of three-axis spectrometers (TAS) to optimise their resolution and luminosity and to interpret experimental data collected with them. The program code includes both a high-speed analytical (Gaussian) convolution algorithm and a Monte Carlo ray-tracing method providing enhanced accuracy in description of most of the spectrometer components.


Simres provides instrument scientists with more flexible (and more realistic) ray-tracing code useful for simulation of newly designed or upgraded instruments and optimisation of their configuration. This version permits to simulate intensity and distribution of neutron beam in both real and momentum subspaces at different positions along the TAS beamline.


A Virtual Three Axis Spectrometer - Using a Three Axis Spectrometer (TAS) is not easy since one has constantly translate parameters from real space to reciprocal space and vice versa

The goal of vTAS is to provide an interactive and graphical display of both the instrument configuration and the corresponding measured space thus making easier the understanding of the behavior of the instrument and its limits.
Simulation mode: vTAS allows experimentation with sample parameters, for example the Miller indices of the unit cell, whilst maintaining a representation of the instruments physical state, for example the location of the walls around the instrument, and its angular limits.

Data viewer mode: vTAS is capable of reading ILL TAS data files. It displays both the data and the corresponding instrument configuration.

vTAS also supports the multiplexed geometry FLATCONE both in the simulation mode and data viewer mode. A version with support for IMPS is now being prepared and a version with support of UFO is anticipated.

The first version of vTAS was developped by Alain Bouvet in 1998.
The new vTAS project was funded by the ILL and NMI3.


If anybody want to share his knowledge in ToF/HR data treatment, he is kindly invited to send his bugg-free well documented code to J. Ollivier. The code will be added to the list after checking. Any programmation language is accepted.