The use of selected neutron absorption resonance filters to suppress spurious events on hot neutron spectrometers

• We measured neutron transmission for eight absorption filters using time of flight.
• Resonance energies, their selectivity and efficiency are extracted for each filter.
• We detail how to choose and optimize filter use in neutron scattering experiments.
• Such filtering can be efficiently used to reduce background and spurious signals.

Resonant absorption can be used as a filter for high energy neutron spectroscopy. Here we report the transmission of eight thin foil filters: erbium, indium, iridium, dysprosium, hafnium, gadolinium, cadmium and samarium, measured using neutron time-of-flight techniques over a range of energies (1 meV to 10 eV). Measured transmission is converted into energy-dependent absorption cross-section which compares closely to tabulated values. Each resonance is characterized from 91 meV (samarium) to 2815 meV (gadolinium) by Lorentzian fits. Possibilities for the use of neutron filters depending on the type of spurious background are discussed and the performance is simulated for a specific example of a hot neutron triple axis spectrometer experiment.