Scientific Reviews: Two-Detector System for Small-Angle Neutron Scattering Instrument

Abstract

Most of the objects of small-angle neutron scattering (SANS) experiments require the measurements of a studied sample in a wide range of momentum transfer (Q-range). Larger Q-range means more reliable determination of a model of the investigated material as well as higher accuracy of its calculated structural parameters. The dynamic range of SANS instruments is normally determined by the size of the detector, which is limited mainly by technical reasons and by the wavelength range of available thermal neutrons in the neutron beam. Even in the case of the largest detector (1 m²) at one of the best beam lines—the D22 instrument at ILL—the dynamic range is about 50. Usually the problem of the Qrange is solved by a sequence of measurements with the detector at different positions. However, it leads to considerable increase in the data acquisition time. Moreover, the problem becomes critical when it is necessary to study processes in real time, especially irreversible processes.

Acknowledgments

We thank Prof. V.L. Aksenov and Prof. A.V. Belushkin for support of this project and the FLNP staff for assisting in the realization of the two-detector system at the IBR-2. A.A. Smirnov is acknowledged for the preparation of the scheme of the spectrometer (Figure 1) and Dr. S. Sergeenkov for useful discussions.

Notes

1. A. I. Kuklin, G. N. Bobarikina, A. A. Bogdzel, V. I. Gordeliy, A. Kh. Islamov, V. Yu. Konovalov, A. D. Rogov and M. Florek. Measurements and Monte-Carlo calculation of neutron spectrum. Parameters of Small Angle Spectrometer Beam Line at the IBR-2 Reactor. JINR Preprint P13-2002-249, Dubna (2002).

3. A. G. Soloviev, A. V. Stadnik, A. Kh. Islamov and A. I. Kuklin. Fitter: The package for fitting experimental data of the YuMO spectrometer by the theoretical form-factors. Version 1.0. Long Write-Up and User's Guide. JINR Communication E10-2003-36, Dubna (2003).