# Navigation Area

# ResLib

# Main content

- Popovici and Cooper-Nathans resolution matrix calculations
- Numerical folding of user-supplied cross sections with resolution function
- Support for single-mode approximation and Voigt profiles
- Built-in least-squares fitting routines
- 2D and 3D Graphics
- 3-axis and crystallographic utilities
- Spectrometer motion simulation

Developed by Andrey Zheludev at Brookhaven National Laboratory, Oak Ridge National Laboratory and ETH Zuerich. Email: .

## What is ResLib?

Perhaps the most important aspect of analyzing inelastic neutron scattering data measured using a 3-axis spectrometer is properly taking into account the experimental resolution. Even though one is fairly confident that the Gaussian approximation to the resolution function is accurate, thanks to the Central Limit Theorem, the problem is still quite non-trivial. In general, to properly analyze experimental scans using a parameterized model cross section S(Q,w,p) , one needs to 1) be able to calculate the resolution function at each data point, given the spectrometer configuration and sample parameters, 2) numerically convolute the theoretical cross section with this resolution function; and 3) fit the convoluted cross section to the data. The ResLib library is designed to accomplish these tasks.

## Manual

The manual (PDF, 376 KB) contains a detailed description of all ResLib functions and a discussion of the actual formulas and approximations used in the calculations.

## The latest version is ResLib 3.4c (October 2009)

This version is identical to ResLib 3.4 except for a few bug fixes. As pointed out by Sibel Bayrakci and several others, there was a mistake in the formula used to calculation of the effective collimations provided by neutron guides in ResMat.m. Additional corrections were made in the calculation of scattering direction and sample orientation.

Download ResLib3.4c (ZIP, 375 KB)

Check out ResLibCal which provides a frontend to ResLib, ResCal5, Res3ax and ResCal:

http://ifit.mccode.org/Applications/ResLibCal/doc/ResLibCal.html