Compact chopper spectrometers for pulsed sources

6th European Conference on Neutron Scattering

Voigt, J.^1,2 ; Violini, N.^1,2 ; Schweika, W.^1,2

JCNS, PGI, JARA-FIT, Forschungszentrum Jülich GmbH, Jülich

52425, Germany^1

European Spallation Source ESS ERIC, Lund, Sweden^2

关键词: Deep inelastic scattering;    Detector coverages;    Direct geometry;    High intensity;    High repetition rate;    Neutron energy;    Repetition rate;    Spectral distribution;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/746/1/012018/pdf
DOI  :  10.1088/1742-6596/746/1/012018

来源: IOP

【 摘 要 】

We report on the opportunities for direct geometry chopper spectrometers (DGCS) by polychromatic illumination of the sample. At pulsed sources the use of multiple initial neutron energies appears naturally, if the repetition rate of chopper in front of the sample is larger than the repetition rate of the source. As a consequence, a large part of the spectrum is measured redundantly with variable energy and momentum transfer resolution. This can be used to optimize a chopper instrument for deep inelastic scattering, relaxing the requirements on the pulse length, by which the sample is illuminated, and on the secondary flight path, while the width of the spectral distribution must be narrowed down. This can open the path to new types of compact direct geometry chopper spectrometers, which need comparably small areas of detector coverage and allow very high repetition rates to provide a high intensity even if sample size and divergence distributions are limited.