MARMOT at full swing

The MARMOT system is the latest major technical breakthrough in neutron spectrometers. Designed and built in-house at the ILL, it offers a new way to simultaneously analyse a wide range of neutron energies across a wide range of scattering angles. It is based on an innovative, bent silicon crystal technology, which enables new designs for monochromators and analysers specifically to enhance inelastic neutron scattering experiments. 

During the last reactor cycle at the ILL in 2025, which ended in late October, the MARMOT project reached a crucial milestone. The secondary spectrometer structure, with seven channels (out of 30 foreseen in total), was fully equipped with analyser crystal arrays and position-sensitive detectors, and was installed and commissioned on the ThALES instrument. The installation of the full system in 2026 will greatly increase the angular range.

MARMOT is a multiplexed, analyser-detector unit with 30 channels simultaneously covering a scattering angle range of 75 degrees. It is an 'energy dispersive detection system’ based on arrays of bent silicon analyser crystals (in perfect focusing condition) combined with position-sensitive detectors in an ingenious geometry, resulting in a continuous energy detection range from 3.5 meV to 7 meV. MARMOT measures large, selected regions in momentum and energy transfer simultaneously, while keeping the high monochromatic flux and good resolution of triple axis spectrometers. This is similar to time-of-flight spectrometers but without the need for beam pulsing and associated reduction in incident neutron flux.

MARMOT has been conceived to observe the dynamics of so-called quantum materials, which exhibit peculiar magnetic properties on an atomic scale, governed by the strange laws of quantum mechanics. Fundamental in nature, this research is essential to understand the collective behaviour of electronic systems under conditions that accentuate their quantum nature, and to contribute to the development of future information communication and storage devices. These insights not only deepen our knowledge of the quantum world but also contribute to future advances in information technologies.