Speaker
Description
Neutron beamlines at spallation sources are exposed to a broad spectrum of neutron energies, from thermal to several hundred MeV, yet no single material can simultaneously moderate and capture neutrons across this entire range. Additive manufacturing offers a route to overcome this limitation by enabling the combination of complementary absorber materials into geometrically tailored, beamline-specific shielding components. The objective of this study was to develop composite filaments enabling attenuation and capture of thermal and fast neutrons, and employ them to print shielding structures for neutron beamlines. Here, we will present the implementation and characterization of a collimator specifically designed for the time-of-flight neutron diffractometer beamline POLDI at the Swiss Spallation Source SINQ. Background measurements at the sample table 12 m away from the collimator demonstrate a reduction of fast and epithermal neutron flux of approximately 20%, while the thermal neutron flux remains unaffected. These results demonstrate the capabilities of absorber-loaded filaments for additive manufacturing, enabling beamline-specific shielding components.