Initial Characterisation of a Prototype TMR Assembly for an Electron-Driven CANS at CERN's CLEAR Facility

The Versatile ULtra-Compact Accelerator-based Neutron source (VULCAN) project is developing a compact accelerator-driven neutron source (CANS) optimised for neutron diffractometry in industrial and university settings. Central to VULCAN is a novel target-moderator-reflector (TMR) assembly optimised to convert a 35 MeV pulsed electron beam into short neutron pulses (FWHM < 20 μs) in the 1.5-3.5 Å wavelength range. To validate the simulation-driven design process, a prototype TMR was developed for testing at CERN’s CLEAR facility, and this paper presents the design, installation, and results of the first experimental campaign. While moderated neutron pulses were successfully detected, significant discrepancies were observed between the experimental and simulated energy spectra. Potential causes are discussed and recommendations for follow-up measurements are provided.