Experimental aspects of neutron scattering

On HET, a high resolution (in neutron terms) of 1-2% is achieved by using a fast 600 Hz Fermi chopper located 10 m from the source. Scattered neutrons are detected in two azimuthal arrays of He detectors, the first at 4 m from the sample covering 3° to T and the second at 2.5 m covering 9° to 29°. A third detector array at 136° has proved to be invaluable in determining (multi) phonon and multiple scattering contributions to the signal. 

The traditional kinematic constraints on high-energy magnetic neutron scattering are severe. A large scalar difference between the incident and scattered neutron wavevectors, and respectively, is required, 

Characteristic parameters of pulsed neutron source time-of-flight chopper spectrometers. 

Source Proton energy (MeV) Target Proton current (pA) Frequency Spectrometer (Hz) (Operational) L/L, (m) Resolution (%) 

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